Guidance
Rationale and impact
- Psychological support for early menopause
- Identifying perimenopause and menopause
- Discussing management options with people aged 40 or over
- Cognitive behavioural therapy for vasomotor symptoms
- Genitourinary symptoms associated with menopause in people with no personal history of breast cancer
- Genitourinary symptoms associated with menopause in people with a personal history of breast cancer
- Vaginal laser treatment
- Management options for depressive symptoms or depression in people with menopause-associated symptoms
- Cognitive behavioural therapy for sleep problems associated with menopause
- Taking medical history of coronary heart disease or stroke into account before offering treatment
- Managing menopause-associated symptoms in people who have taken gender-affirming hormone therapy in the past
- Effect of HRT on life expectancy in people aged 45 and over
- Effect of combined HRT on specific health outcomes in people aged 45 or over
- Effect of oestrogen-only HRT on specific health outcomes in people aged 45 or over
- Cardiovascular disease prevention
- Dementia prevention
- Effects of HRT use in early menopause on specific health outcomes
- Starting and stopping HRT for anyone
Rationale and impact
These sections briefly explain why the committee made the recommendations and how they might affect practice.
Psychological support for early menopause
Why the committee made the recommendation
In the committee's experience, some people can be distressed by going through menopause at an earlier age than expected and earlier than their peers. If someone is experiencing emotional distress to a level that raises concerns, the committee agreed that they may need to be referred to psychology services.
How the recommendation might affect practice
It is common practice to provide psychological support to this group of people. While a potential referral will have a resource impact, support from psychology services will lead to improvements in quality of life and reduce future contacts with health services.
Identifying perimenopause and menopause
Why the committee made the recommendation
Evidence is lacking on the average age of menopause in people from ethnic minority backgrounds. However, the committee was aware, from experience, that people from some ethnic minority groups, and people with some lifelong conditions (for example, Down's syndrome), experience menopause at a younger age. The committee agreed it was important to raise awareness of this so that healthcare professionals can more easily identify symptoms of menopause in ethnic minority populations or in people with lifelong conditions.
How the recommendation might affect practice
The recommendation will raise awareness that people from some ethnic minority groups, and those with some lifelong conditions, experience menopause at a younger age. It is unclear whether this will change clinical practice, but it might lead to earlier identification of menopause and earlier management of menopause symptoms.
Discussing management options with people aged 40 or over
Recommendations 1.4.1 to 1.4.4
Why the committee made the recommendations
Based on experience, the committee agreed that these basic principles of care would allow people to make an informed choice about management options:
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using an individualised approach with discussions about benefits and risks of any management option and
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tailoring information to individual circumstances and potential risk factors.
Hormone replacement therapy
The committee noted there are different ways of prescribing hormone replacement therapy (HRT) in terms of mode of administration, types of hormones, schedule, and individualised dose and duration. All these options influence benefits and risks so the best combination of them differs from one person to another and should be carefully chosen with, and for, each person. The committee agreed that clinicians should provide and discuss information about all this so that the person can take an active part in shared decision making.
Baseline risks of specific health outcomes and the benefits and risks of HRT also depend on a person's age at the start of perimenopause, as well as their individual circumstances and risk factors. It is particularly important to take age into account, for example, when thinking about the:
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risks of dementia or stroke with HRT and
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use of HRT in people experiencing early menopause.
The committee agreed it was essential to discuss duration of use when a person chooses to take HRT. It was decided that this was important because, even if the exact duration is unknown at the start, people would get an idea (from the clinician's knowledge about typical use) how long they may be taking HRT for and be made aware that this would be discussed again at reviews. The committee also agreed that it is impossible to recommend 1 specific duration of use because this would depend on several factors, including the reason for starting HRT and a person's medical history, age and symptoms. It was agreed that it was important to discuss continuation of HRT at every review because circumstances and preferences could change. The committee acknowledged that, in many people, menopause symptoms may return when HRT is stopped. They agreed this should also be discussed with the person in the context of duration of use. The person should also be aware that, if this happens, they could restart HRT, if this would still provide the best balance benefits and risks for them.
Cognitive behavioural therapy
Evidence showed that cognitive behavioural therapy (CBT) could be an option for some people with vasomotor symptoms, depressive symptoms or sleep problems. CBT could be used either alongside HRT or, for people for whom HRT is contraindicated or who prefer not to take it, instead of HRT. Several types of CBT (for example, online or group sessions) were found to be effective, but the evidence did not show that 1 option was better than another. The committee therefore recommended that the available options should be discussed with the person. They were also aware that some people needed information on what CBT involves. It was recognised that people have different preferences and needs and that these should be taken into account during these discussions (for example, reasonable adjustments may be needed for people with learning disabilities).
How the recommendations might affect practice
The recommendations reflect best practice principles for shared decision-making. The recommendations will make healthcare professionals aware of what to discuss as part of this process.
Cognitive behavioural therapy for vasomotor symptoms
Why the committee made the recommendation
The committee based the recommendation on both the evidence and their expert knowledge. They looked at evidence on CBT compared with no intervention or to treatment as usual.
There was no evidence available for trans men and non-binary people registered female at birth. However, the committee agreed that the use of CBT for menopause-associated symptoms would be suitable for anyone, regardless of whether they have taken gender-affirming hormone therapy in the past. (This is also covered in the rationale on managing symptoms associated with menopause in people who have taken gender-affirming hormone therapy in the past.)
Overall, the evidence showed CBT was beneficial for women with vasomotor symptoms associated with menopause. The benefits related to 3 outcomes: the frequency of symptoms, severity of symptoms and how much the symptoms bothered the person (using a questionnaire that measured 'distress or bother'). The greatest effect was seen in how much symptoms bothered the person – many women felt their symptoms affected them less after taking part in CBT.
The committee also discussed the following limitations that affected the quality of the evidence:
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some concerns related to study design and to potential bias in the way studies were carried out
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uncertainties around outcomes, with different results being obtained for different outcome measurement scales and subgroups
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uncertainties around how large the effect of CBT was, even when it was found to be effective.
For this reason, the committee decided to recommend CBT in addition to HRT, or as an option for people who prefer not to take HRT or for whom HRT is contraindicated. They also agreed the chosen CBT approach should be specifically designed for menopause symptoms.
How the recommendation might affect practice
These recommendations are a change to clinical practice. While wider use of CBT as an additional option could increase costs and add pressure to already limited services, especially in the short-term, it also gives people more choices for managing symptoms, including the option to have both CBT and HRT. This may lead to better outcomes.
The committee noted that there are long waiting times for CBT. They also noted that people currently trained in providing this kind of therapy may not be familiar with menopause-specific CBT, so training on this may incur costs and increase waiting times in the short term. However, online and group CBT may be easier and less costly to adapt to be menopause specific. There are also resources available to train people in providing menopause-specific CBT (that could also inform the adaptation of online CBT), which could facilitate implementation.
Currently, the treatment recommended for vasomotor symptoms associated with menopause is HRT. Access to CBT may address some health inequalities, providing other effective options for those who cannot or do not wish to use pharmacological treatments for menopause symptoms.
Genitourinary symptoms associated with menopause in people with no personal history of breast cancer
Recommendations 1.5.4 to 1.5.12
Why the committee made the recommendations
The committee discussed evidence from network meta-analyses (NMA) which looked at a number of management options for specific subtypes of genitourinary symptoms associated with menopause such as vaginal dryness, pain with sex, and vulvovaginal discomfort or irritation. They also took into account evidence from the health economic model developed for the 2024 update of this guideline.
There was no evidence available for trans men and non-binary people registered female at birth. The committee agreed that their conclusion from the available evidence could be extended to those who have never taken gender-affirming hormone therapy. But they did not think they could be extended to those who have taken this type of therapy in the past, because it is not known whether such therapy would alter the benefits and risks of any management option (especially hormonal treatments), or which management option might be best for the person.
Evidence showed that vaginal oestrogen (particularly estriol but also oestradiol) was effective in reducing vaginal dryness and pain with sex. Estriol also showed effectiveness in reducing vulvovaginal discomfort or irritation. The economic model conducted for this review showed that vaginal oestrogen was cost-effective.
There was limited evidence on long-term use of vaginal oestrogen preparations. However, the committee acknowledged that efficacy and tolerability would be assessed regularly, as per the recommendations on reviewing treatment.
To gain a better understanding of it, the committee made a recommendation for research on the safety of vaginal oestrogen when used for more than 12 months.
Based on their expertise, the committee agreed that what is known about the safety of long-term use should be taken into account and discussed with the person before offering vaginal oestrogen. They agreed that the following points should also be brought up:
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Serious adverse effects from vaginal oestrogen are rare. For example, the committee was aware of the 2019 Medicines and Healthcare products Regulatory Agency drug safety update on HRT safety advice, which states that there is no evidence of an effect of vaginal oestrogen on breast cancer risk. This was consistent with the findings from the NMA, which showed that discontinuation due to adverse events was relatively low.
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In the committee's experience, people are not always aware that symptoms often return when vaginal oestrogen is stopped.
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Because absorption into the bloodstream is minimal, there is no need to combine vaginal oestrogens with systemic progestogen treatment to protect the person against endometrial hyperplasia and cancer (whereas, with systemic HRT, people with a uterus need progestogen treatment for protection – see the rationale section on starting and stopping HRT).
Preparations were not all shown to be equally effective. However, there were also uncertainties around the differences observed. So, the committee agreed that, overall, it was unlikely that 1 type of vaginal oestrogen preparation would be more effective than another. They concluded that people with genitourinary symptoms associated with menopause should be given different options for vaginal oestrogen preparations so they could choose the 1 they prefer.
The committee thought that people did not always realise that moisturisers or lubricants can be used alone or in addition to vaginal oestrogen and, therefore, thought that this information should be included in discussions about management options.
The NMA suggested that non-hormonal vaginal moisturisers and lubricants were less effective than vaginal oestrogen, but a smaller proportion of people stopped using their treatment when using non-hormonal vaginal moisturisers or lubricants than when using other types of treatments. This may suggest that, when non-hormonal vaginal moisturisers and lubricants worked for a person, the person felt comfortable to keep using them (for example, because these are readily available over the counter options). While the evidence highlighted uncertainty around the effectiveness of non-hormonal moisturisers and lubricants, based on their experience, the committee decided that moisturisers and lubricants could be tried when vaginal oestrogen is contraindicated or not preferred.
The committee discussed the role of vaginal prasterone and oral ospemifene in the management of genitourinary symptoms associated with menopause. They noted that both these medicines are more expensive than vaginal oestrogen, moisturisers or lubricants. However, the NMA showed them to be effective in reducing vaginal dryness and pain with sex but not vulvovaginal discomfort or irritation. They were also seldom discontinued because of adverse events.
The economic model showed vaginal prasterone was not cost-effective as a first-line option. However, given its clinical effectiveness, the committee agreed that it could be offered as a second-line management option when other options (vaginal oestrogen, or non-hormonal moisturisers or lubricants) are ineffective for persisting genitourinary symptoms or are not tolerated.
Evidence showed that ospemifene was not cost-effective and could therefore not be recommended as a first-line treatment option for all people with genitourinary symptoms associated with menopause. However, the committee noted that, for some people, local application of vaginal oestrogen may be impractical. For example, people with physical or intellectual disabilities may find it difficult to use local vaginal oestrogen. Ospemifene is an oral tablet and should therefore be considered as an option in such specific circumstances.
The committee was aware that the symptoms of overactive bladder can occur alongside genitourinary symptoms associated with menopause and that vaginal oestrogen can be given in these circumstances. They decided not to include people with a personal history of breast cancer in the recommendation on this because vaginal oestrogen is not the first-line treatment for genitourinary symptoms associated with menopause in this population.
How the recommendations might affect practice
The evidence showed that the most cost-effective option for the treatment of genitourinary symptoms associated with menopause is vaginal oestrogen, which is routinely offered in current practice. The recommendations will standardise practice rather than change it.
Genitourinary symptoms associated with menopause in people with a personal history of breast cancer
Recommendations 1.5.13 to 1.5.18
Why the committee made the recommendations
The committee acknowledged that evidence was sparse, with only 4 studies providing information on breast cancer recurrence in people with a personal history of breast cancer taking vaginal hormone treatment for genitourinary symptoms associated with menopause. The committee also had methodological concerns about some of the studies, particularly about:
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how they accounted for confounding factors (including how many factors, which factors and how they accounted for these factors in their analysis of data) and
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duration of follow-up, which was not long enough to capture breast cancer recurrence.
There was no evidence available for trans men and non-binary people registered female at birth. The committee agreed that their conclusion from the available evidence could be extended to those who have never taken gender-affirming hormone therapy. But they did not think they could be extended to those who have taken this type of therapy in the past, because it is not known whether such therapy would alter the benefits and risks of any management option (especially hormonal treatments), or which management option might be best for the person.
The committee discussed the evidence comparing vaginal oestrogen to no treatment in women with a personal history of breast cancer. Most of the evidence included all women together and so did not distinguish between those who used adjuvant treatment for breast cancer and those who did not. Based on this evidence, it is not possible to say with certainty whether vaginal oestrogen, when used for genitourinary symptoms associated with menopause, leads to any change in breast cancer recurrence or not.
The uncertainties around the evidence also led the committee to agree that:
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The first choice for people with a personal history of breast cancer and genitourinary symptoms associated with menopause should be non-hormonal moisturisers and lubricants.
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Vaginal oestrogen should only be considered as a second-line option, when non-hormonal treatment has not been effective, and symptoms continue to impact negatively on the person's quality of life. The committee noted that people may not realise that non-hormonal moisturisers and lubricants could also be used in combination with vaginal oestrogen, so they agreed to highlight this.
The committee made these recommendations because:
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non-hormonal treatment may be less effective than local hormonal treatment but
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although it is important to treat menopause-associated symptoms, the risk of breast cancer recurrence is a greater concern.
The committee advised that the mechanism of action of aromatase inhibitors makes genitourinary symptoms likely. However, the mechanism of action of tamoxifen is less likely to cause genitourinary symptoms and may even alleviate some of them. Vaginal oestrogen may also lessen the efficacy of aromatase inhibitors.
The committee agreed it could not be confident about the evidence on the safety of local vaginal oestrogens in those taking either tamoxifen or aromatase inhibitors. This was because of:
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concerns about the quality of the evidence and
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lack of data comparing the risk of breast cancer recurrence in people taking aromatase inhibitors alone with the same risk in people taking vaginal oestrogen (the comparison was aromatase inhibitor versus aromatase inhibitor plus vaginal oestrogen).
For this reason, the committee agreed that, if vaginal oestrogen is considered for people on aromatase inhibitors as an adjuvant treatment, treatment options should be discussed with a breast cancer specialist (for example, this may include switching to tamoxifen).
The committee noted that treatment decisions would need to be tailored to each person because:
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Some people have a lower risk of breast cancer recurrence than others (as covered by NICE's guideline on early and locally advanced breast cancer). The committee decided that this was an important factor because it is worse to potentially add to the risk of those who already have a high risk than those who have a low risk of recurrence.
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Vaginal oestrogen is absorbed locally. Some of it is absorbed systemically, that is, further into the body, but, compared with systemic HRT, the amount is minimal, and so it may or may not be a sufficient amount to affect breast cancer recurrence. This makes it difficult to assess the safety of vaginal oestrogen with respect to breast cancer recurrence.
In someone with an oestrogen receptor negative breast cancer, oestrogen does not affect the growth of cancer cells, but in someone with an oestrogen receptor positive breast cancer, it increases the risk of recurrence.
In someone with an oestrogen receptor positive breast cancer taking adjuvant treatment:
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if this treatment inhibits the production of oestrogen (in the ovaries or in fat or muscle tissues), it will have no effect on any oestrogen coming from a source outside the body, and this oestrogen would then be able to bind to cancer cells and stimulate their growth but
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if this treatment stops oestrogen from binding to oestrogen receptors (regardless of whether the oestrogen is produced by the body or absorbed from some treatment), it will stop oestrogen, regardless of source, from binding to receptors on cancer cells and so their growth will not be stimulated.
There was relatively little evidence for the use of vaginal oestrogen to manage genitourinary symptoms associated with menopause after breast cancer, particularly related to long-term use and use in conjunction with adjuvant therapy. Therefore, the committee made a recommendation for research on the safety of vaginal oestrogen in terms of breast cancer recurrence.
People who carry genetic variants that increase the risk of breast cancer
No evidence on the use of vaginal oestrogen was identified for people who carry genetic variants that increase the risk of breast cancer. The committee therefore decided that it could not make a recommendation but made a recommendation for research on the safety of vaginal oestrogens for people who have a high genetic risk of breast cancer.
How the recommendations might affect practice
The recommendation about the use of non-hormonal treatment options as first-line treatment for people with a personal history of breast cancer and genitourinary symptoms associated with menopause is in line with current practice. There is variation in:
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the clinical factors taken into account when considering local vaginal oestrogens after an ineffective first-line treatment
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when to seek specialist oncology advice
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what is discussed with people, particularly around the uncertainty of the evidence.
The recommendations will standardise practice.
Vaginal laser treatment
Why the committee made the recommendation
The committee made a recommendation on vaginal laser treatment that applies to people with genitourinary symptoms associated with menopause, regardless of whether they have a personal history of breast cancer.
The evidence showed that laser treatment was effective for all outcomes. However, the committee agreed that, despite some promising results, the evidence base was too small. In addition, laser treatment has a potential for harm (for example, scarring) and evidence showed it was not cost-effective. As a result, it should only be offered in the context of research. The committee also made a recommendation for research on vaginal laser treatment to address this.
There was no evidence available for trans men and non-binary people registered female at birth. The committee agreed that their conclusion from the available evidence could be extended to those who have never taken gender-affirming hormone therapy. But they did not think they could be extended to those who have taken this type of therapy in the past, because it is not known whether such therapy would alter the benefits and risks of any treatment (especially hormonal treatments), or which treatment option might be best for the person.
How the recommendation might affect practice
Laser treatment was not included in the previous version of this guideline, but the recommendation to only consider it in the context of research will not affect practice.
Management options for depressive symptoms or depression in people with menopause-associated symptoms
Recommendations 1.5.21 and 1.5.22
Why the committee made the recommendations
The committee made recommendations based on the evidence which looked at CBT compared with no treatment or to treatment as usual, in the context of menopause. The common criteria used in all studies to show that women had experienced or were approaching menopause was the presence of vasomotor symptoms.
There was no evidence available for trans men and non-binary people registered female at birth. However, the committee agreed that the use of CBT for menopause symptoms would be suitable for anyone, regardless of whether they have taken gender-affirming hormone therapy in the past. (For more details, see the rationale on managing symptoms associated with menopause in people who have taken gender-affirming hormone therapy in the past.)
There were many different scales and measurements for mental health-related symptoms, and, in the context of menopause:
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most of the evidence on depressive symptoms showed no difference between CBT and the comparison groups (no treatment or treatment as usual)
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some evidence showed that CBT improved mood in women with depressive symptoms
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no evidence showed that CBT might make depressive symptoms any more severe.
There were some concerns about the evidence. These related to study design and to biases in the way studies were carried out. There were also uncertainties around:
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the outcomes, with different results being obtained for different outcome measurement scales and subgroups and
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how large the effect of CBT was, even when it was found to be effective.
However, the committee acknowledged that the overall effectiveness of CBT for depressive symptoms is established (see NICE's guideline on depression in adults). For this reason, they agreed that CBT should be a management option for depressive symptoms associated with vasomotor symptoms.
If depression is suspected or diagnosed, the committee noted that the optimal treatment plan can only be achieved by following both this menopause guideline and NICE's guideline on depression in adults.
How the recommendations might affect practice
These recommendations could lead to a change to clinical practice. Wider use of CBT could increase costs and add pressure onto already limited services, especially in the short term. However, it also gives people more management choices, including the option to have both CBT and HRT. Having more options may result in better outcomes.
There are currently long waiting times for CBT. However, the use of online and group CBT may make it easier and less costly to introduce CBT for depressive symptoms associated with menopause, where this option is not already in place.
Cognitive behavioural therapy for sleep problems associated with menopause
Why the committee made the recommendation
The committee based the recommendation on the evidence on CBT compared with no treatment or compared with treatment as usual.
There was no evidence available for trans men and non-binary people registered female at birth. However, the committee agreed that the use of CBT for menopause symptoms would be suitable for anyone, regardless of whether they have taken gender-affirming hormone therapy in the past. (For more details, see the rationale on managing symptoms associated with menopause in people who have taken gender-affirming hormone therapy in the past.)
Evidence showed CBT improved sleep quality, but this varied depending on the scale used to measure sleep disturbances. The committee agreed it was difficult to define difficulties with sleep, but the evidence showed that CBT was beneficial for various aspects of sleep, as defined by each scale (for example, the measures contributing to scales included the number of hours of sleep per night, how long it takes to fall asleep and the number and duration of night-time awakenings; there were also some specific scales for insomnia). The committee acknowledged there may be other options to manage difficulties with sleep associated with menopause. NICE will monitor evidence on these for a future update. While not all the CBT approaches used in the evidence were specifically developed for menopause-associated symptoms, the committee agreed that this kind of CBT would be more effective given that the evidence showed that:
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the women with sleep problems also had vasomotor symptoms which can negatively impact sleep and
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menopause-specific CBT was also beneficial for the management of vasomotor symptoms.
The committee agreed that the evidence had some limitations, including uncertainties around:
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outcomes, with different results being obtained for different outcome measurement scales and subgroups
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how large the effect of CBT was, even when it was shown to be effective.
The committee also had concerns around study design and biases around how studies were carried out.
As a result, they recommended CBT as an option rather than as routine management for sleep problems associated with menopause.
How the recommendation might affect practice
These recommendations could lead to a change to clinical practice. Although increased use of CBT could have a resource impact and add pressure to already limited services, especially in the short term, it also provides more management choices, including the option to have both CBT and other treatments (including HRT). This may lead to better outcomes.
There are currently long waiting lists for CBT and people who are already trained in this type of therapy may need further training before they can provide menopause-specific CBT. However, the use of online or group CBT may make it easier and less costly to adapt as menopause-specific CBT. The committee was aware of existing resources that can be used to train people in providing menopause-specific CBT (including adapting online CBT). They agreed that this would facilitate implementation.
Taking medical history of coronary heart disease or stroke into account before offering treatment
Why the committee made the recommendation
For people with a history of coronary heart disease or stroke, the committee agreed that different risk factors mean that people have different baseline levels of risk. They concluded that decisions on HRT use for menopause-associated symptoms would need to be tailored to the person and their particular risk factors and risk levels and that, therefore, these decisions should be made with a healthcare professional with expertise in menopause.
How the recommendation might affect practice
It is current practice that people with pre-existing conditions get expert advice on HRT as a treatment option for menopause-associated symptoms. However, there is variation in which expert would be consulted on this. This recommendation will standardise practice.
Managing menopause-associated symptoms in people who have taken gender-affirming hormone therapy in the past
Recommendations 1.5.34 and 1.5.35
Why the committee made the recommendations
The committee noted a lack of evidence on HRT use in trans men and non-binary people registered female at birth who have taken gender-affirming hormone therapy in the past. This uncertainty means that, for example, it is not known whether past hormone treatment could influence the choice of HRT, or whether giving HRT to someone who previously had hormone therapy would alter their health risks. For this reason, the committee agreed that trans men and non-binary people registered female at birth who have taken gender-affirming hormone therapy in the past should be able to discuss their menopause-associated symptoms with a healthcare professional with expertise in menopause. They can then make a shared decision about any potential treatment the person may wish to have. Because of the lack of evidence, the committee also made a recommendation for research on the impact of HRT on health outcomes for trans men and non-binary people registered female at birth, which covers people who have never taken gender-affirming hormone therapy, or who have taken it in the past but are not currently taking it.
The committee discussed the evidence related to CBT. This did not include evidence related to trans men or non-binary people registered female at birth. However, the committee agreed that the use of CBT for menopause symptoms would be suitable for any person, regardless of whether they have taken gender-affirming hormone therapy in the past.
The committee decided to make a specific recommendation for trans men and non-binary people registered female at birth who have taken gender-affirming hormone therapy in the past to promote equality in access to CBT services for managing menopause-associated symptoms within these groups, acknowledging their unique experiences and needs. Because, without further evidence, other recommendations in this guideline cannot be extended to these groups, the committee agreed that a separate recommendation would highlight CBT as a management option for these groups.
How the recommendations might affect practice
In the committee's experience, there is no clear current practice related to the treatment of menopause-associated symptoms in people who have taken gender-affirming hormone therapy in the past. The committee agreed that access to both advice from a healthcare professional with expertise in menopause and to CBT were a matter of equality and inclusivity.
The recommendations may increase the number of referrals both to healthcare professionals with expertise in menopause, and for CBT. The committee noted that there is pressure on services providing CBT. However, the recommendations should also lead to more appropriate care and improved outcomes for people who have had gender-affirming hormone therapy in the past.
Effect of HRT on life expectancy in people aged 45 and over
Why the committee made the recommendation
The committee discussed the evidence on the impact of HRT on all-cause mortality (life expectancy). The multitude of confounding factors that may affect life expectancy meant that evidence had to be restricted to randomised controlled trials (RCTs). This is because, in RCTs, participants are randomly assigned to different treatment groups, which helps control known and unknown confounders.
The committee noted that high-quality evidence showed no difference in mortality with either oestrogen-only or combined HRT compared with not taking HRT. They agreed that this was an important finding and therefore emphasised the need to tell people thinking about either treatment option that taking combined or oestrogen-only HRT is unlikely to affect life expectancy.
The committee looked at the analysis for groups of women starting HRT at different ages. They noted that, for most age groups, there was no difference in mortality between those who are taking or have taken HRT compared with placebo. There was also no significant variation in this difference depending on the age of starting HRT.
A decrease in all-cause mortality was reported for 1 isolated subgroup (women starting oestrogen-only HRT aged between 50 and 59). In isolation, this was a statistically significant figure. But in a wider context, it cannot be interpreted as good evidence of a different effect in this group. This is because:
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there was no identifiable pattern of change in risk as people aged and
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the statistical analysis showed that any differences observed between age groups could be down to random chance and therefore did not represent a real difference between age groups.
As a result, the committee did not refer to this decrease in all-cause mortality in the recommendation.
How the recommendation might affect practice
It is current practice to discuss benefits and risks with people when treatment options are being considered. The effect of treatment on life expectancy is an important part of these discussions and was not covered in the previous version of this guideline. The recommendations will standardise the information that will be given. But it is unclear how this will change the treatment choices made and how this will impact on practice.
Effect of combined HRT on specific health outcomes in people aged 45 or over
Recommendation 1.6.2 and table 1
What this rationale covers
The committee highlighted the importance of presenting people with a complete picture of benefits and risks associated with HRT to enable shared and informed decision making.
This rationale briefly describes the available evidence on combined HRT and how it affects risks related to:
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cancer: breast
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cancer: endometrial
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cancer: ovarian
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coronary heart disease
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stroke
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dementia.
It also covers other considerations related to cardiovascular disease, and the need for further research in this area.
There was no evidence available for trans men and non-binary people registered female at birth. The committee agreed that their conclusion from the available evidence could be extended to those who have never taken gender-affirming hormone therapy. But they did not think it could be extended to those who have taken this type of therapy in the past, because it is not known whether such therapy would alter the benefits and risks of any treatment (especially hormonal treatments), or which treatment option might be best for the person. So, they made a recommendation for research on the impact of HRT on health outcomes for these groups. Combined and oestrogen-only HRT are prescribed to different groups of people, and so the committee looked separately at the benefits and risks associated with the 2 types of HRT.
Why the committee made this recommendation
Cancer: breast
In line with other NICE guidance, the committee agreed that advice needs to be tailored to the person according to their individual risk factors, such as having a family history of breast cancer, living with overweight, or drinking alcohol. The committee acknowledged that people also need to be made aware that these factors will affect absolute risks of breast cancer both when not taking and when taking HRT.
The committee discussed evidence on the effect of taking HRT on breast cancer incidence and breast cancer-related mortality that came from:
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randomised controlled trials (RCTs) and
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a meta-analysis of individual patient data from observational studies.
Overall, it showed the risk of breast cancer incidence was consistently greater with combined HRT than with oestrogen-only HRT. The committee therefore looked in more detail at how combined HRT or oestrogen-only HRT each might affect the risk of breast cancer.
RCT evidence
Evidence from RCTs showed an increased risk of breast cancer incidence for women who are taking or have taken combined HRT compared with women taking placebo. The group included in the trial took combined HRT for approximately 6 years and was followed up for breast cancer for about 7 years after the trial ended.
The evidence showed that, with combined HRT, breast cancer risk was increased regardless of ethnicity or whether there was a family history of breast cancer.
Observational study evidence
Evidence from observational studies was consistent with evidence from the RCTs but provided further information on the duration and recency of use. It showed that, for women who were taking combined HRT, the risk of breast cancer incidence:
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was higher than in those who did not take HRT
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started increasing in the first year of use
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increased with duration of use.
For women who had taken combined HRT in the past, it showed that the risk of breast cancer incidence:
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remained higher than for women who did not take HRT
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was greater the longer women had used combined HRT
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reduced after stopping HRT but was still increased for as long as at least 10 years after stopping use.
The evidence showed that breast cancer risk with sequential combined HRT is lower than with continuous combined HRT but is higher than without HRT. The committee therefore decided that this should be discussed as part of shared decision making so that people can make an informed choice.
All types of progestogen were associated with an increased risk of breast cancer incidence, although there was limited evidence on the risk of breast cancer incidence with micronised progesterone or dydrogesterone. Overall, there was insufficient evidence to say whether micronised progesterone or dydrogesterone may lead to a different risk of breast cancer incidence and therefore the committee made a recommendation for research on whether different types of progestogen in HRT alter breast cancer risk.
It was unclear from the evidence whether, for people who take HRT, the risk of breast cancer changes with the mode of administration. The committee therefore made a recommendation for research on modes of administration for systemic HRT.
Cancer: endometrial
The committee discussed evidence from RCTs and observational studies.
Some of the RCT evidence showed that using continuous combined HRT decreased the risk of endometrial cancer for women taking combined HRT, compared with women not taking HRT.
For women currently taking continuous combined HRT, with any duration of use, some observational studies showed a reduced risk of endometrial cancer while others showed that there was no difference in risk of endometrial cancer compared with women not taking HRT.
The committee discussed the well-established association between oestrogen-only HRT and the risk of endometrial cancer. They agreed it was important to explain to people with a uterus that:
-
this is why they would be offered combined HRT as per recommendation 1.8.1 in the section on starting HRT but
-
although oestrogen has an adverse effect on the endometrium when used on its own, progestogens counteract this in a dose-dependent manner.
They concluded that continuous combined HRT, where progestogen is taken every day with oestrogen, decreases the risk of endometrial cancer.
Evidence from another observational study showed that sequential combined HRT, when used for 10 years or more, increases the risk of endometrial cancer, but not when it is used for less than 10 years. Based on their own knowledge and experience, the committee agreed that the risk is likely to increase slowly over time. They agreed that, with sequential combined HRT, the protective effect of progestogen increases with the number of days on which progestogen is taken every month.
Because the way sequential HRT is taken may vary in duration of use, days of progestogen per cycle, and oestrogen dose, the committee decided to highlight how different sequential HRT regimens and duration of use affect the risk of endometrial cancer. However, they recognised that, overall, this corresponded to a very slight increase in the absolute risk of endometrial cancer.
Cancer: ovarian
The committee discussed the evidence from RCTs as well as from observational studies.
Overall, evidence from an RCT showed that there were more ovarian cancer cases in people taking combined HRT than in people not taking HRT, but the difference was not statistically significant. The committee noted that the number of people diagnosed with ovarian cancer was very small in both groups and this made the evidence less robust.
The observational evidence showed that the risk of ovarian cancer increased with HRT use. The committee noted that both the number of participants and the number of diagnosed cases of ovarian cancer were far larger in the observational evidence than in the RCT, which made the findings more robust.
However, the committee agreed that, although the risk was increased overall, the risk was small in absolute terms, especially with the low baseline risk of ovarian cancer. Overall, there was an increase in ovarian cancer incidence by 1 in 1,000. The committee agreed that all of this should be explained when HRT is being considered.
Coronary heart disease
The committee based their recommendations on evidence from RCTs and observational studies.
The majority of the RCT and observational evidence both showed that the risk of coronary heart disease did not increase when taking HRT. The committee agreed this information should be shared with people to allow them to make an informed decision.
The committee also discussed the evidence on the possible impact of 2 factors:
-
the length of time between menopause and first use of HRT
-
duration of HRT use.
They looked at coronary heart disease risk for different subgroups, and at the statistical significance of any differences observed between these subgroups. As a result, they agreed they could not make any recommendations about the impact of either of these factors on coronary heart disease risk in people taking HRT. This is because there were:
-
no statistically significant subgroup differences in the RCT evidence and
-
inconsistent results between different observational studies.
Findings from the RCT evidence did not all lead to the same conclusions.
For coronary heart disease and cardiac event composite scores, most RCT evidence showed no difference between combined HRT and placebo. This was shown for both continuous and sequential HRT.
However, some isolated results were not in line with this overall trend, but for most of them:
-
the isolated results were not statistically significant or
-
the difference between the group in which these results were obtained and other subgroups was not statistically significant.
See evidence review C: cardiovascular disease and stroke for further discussion of this.
Stroke
The committee based their recommendations on RCTs and observational studies.
Evidence showed a significant difference in risk depending on the mode of administration. The use of combined HRT does not increase the risk of stroke when the oestrogen component is taken transdermally, but it does increase the risk if it is taken orally. These findings were supported by observational evidence. The committee decided that it was important to share this information so that it could be taken into consideration.
However, national statistics show that the baseline risk for stroke in women aged under 60 is very low. The committee agreed that this should be explained to anyone thinking about HRT because the risk may remain small despite any change in risk reported in the RCT and observational study findings.
RCT evidence
The RCTs showed that, overall, there is an increased risk of stroke in women currently taking combined HRT with oral oestrogen.
Evidence on duration of use showed that risk of stroke:
-
did not increase when combined HRT was used for up to 4 years but
-
increased when combined HRT was taken for 5 to 9 years.
Evidence related to age at starting combined HRT containing oral oestrogen also showed a greater risk of stroke in women currently taking HRT. This risk increased with age at starting HRT (that is, the older people were when they started taking HRT). This was when HRT was taken for 5 to 9 years.
Evidence also showed significant differences in the risk of stroke depending on ethnicity. Among those taking combined HRT, the risk of stroke was greater in women of Black ethnicity compared with people from other backgrounds, though numbers of people affected by stroke in all ethnic minority groups were small. Because of the small size of the population taking part in the trials, the evidence was not very robust, so the committee reflected this uncertainty by explaining that the risk 'may' be greater for Black people. The committee agreed that all of this should be explained to people from ethnic minority backgrounds to help them reach a decision.
Observational evidence
Observational evidence on oral oestrogen doses as part of combined HRT, when compared with not taking HRT, showed:
-
an increased risk of stroke in women taking continuous combined HRT when the oestrogen dose was high and
-
no difference in risk when the oestrogen dose was lower.
Impact of timing of HRT for menopause symptoms on risk of coronary heart disease
There was not a lot of data to check whether the following factors impact on risk of coronary heart disease:
-
the age of the person when they start HRT and
-
the time between a person's menopause and when they start HRT.
This resulted in what is called 'lack of statistical power'. In other words, the lack of data means that statistical test could show a difference where there is none.
In what little data was available, the risk did not have a clear tendency to decrease or increase with either of the above 2 factors (that is, with the age of the person when they start HRT or the time between a person's menopause and when they start HRT).
As a result, the committee decided to make a recommendation for research on the impact of timing of HRT on risk of coronary heart disease.
Impact of the type of progestogen in combined HRT on cardiovascular disease risk
There was insufficient evidence to conclude whether, as part of HRT, different progestogens had different impact on risk of cardiovascular disease. The committee made a key recommendation for research on different types of progestogen.
Impact of mode of administration of combined HRT on coronary heart disease
There was insufficient evidence on whether 1 mode of administration of combined HRT differed to another in its impact on risk of coronary heart disease. The committee therefore made a key recommendation for research on different modes of administration.
Risk of cardiovascular disease with HRT in people from ethnic minority backgrounds
The committee noted that there was little evidence on how HRT affects people from ethnic minority backgrounds in terms of cardiovascular health and stroke (as well as all other health outcomes), so they made a recommendation for research on the impact of HRT on health outcomes for these groups of people.
Other considerations relating to cardiovascular disease
The committee were aware of systematic reviews by Boardman et al. (2015), Kim et al. (2020) and Salpeter et al. (2006) – see the list of excluded studies in evidence review C: cardiovascular disease and stroke. These 3 systematic reviews did not meet the inclusion criteria of NICE's 2024 evidence review because:
-
they combined data for participants who received combined HRT and oestrogen-only HRT (Boardman et al. 2015) or
-
some individual studies included within a review did not match NICE's 2024 criteria and therefore the entire systematic review could not be included (Kim et al. 2020 and Salpeter et al. 2006).
The studies included in these systematic reviews were checked and any that matched the relevant criteria were included in NICE's 2024 evidence review.
However, the committee did comment on whether the conclusions made in NICE's 2024 evidence review aligned with the findings of these 3 systematic reviews. Although there were differences observed in certain areas, none of them challenged the overall conclusion that HRT does not increase coronary heart disease risk.
Dementia
The committee noted that there was relatively little evidence on dementia compared with other health outcomes, with only 7 studies identified. They acknowledged that most of the evidence was from observational studies and so they very carefully looked at how various confounders had been adjusted for.
The committee agreed that some of the evidence did not make the necessary adjustments for confounding factors, such as socioeconomic status, or did not reliably ascertain incidence of dementia.
To guide their discussions and support the recommendations, the committee agreed to focus on 2 observational studies, 1 from the UK and the other from Denmark (which both made the most appropriate adjustments for confounders). They also focused on the Women's Health Initiative Memory Study (WHIMS) of women starting HRT over the age of 65, which is based on data from an RCT from the Women's Health Initiative (WHI).
The committee agreed that the evidence from the 2 observational studies was inconsistent:
-
One study showed no difference in risk of dementia between combined HRT use and no HRT, with different durations of use.
-
The other study showed an increase in incidence of dementia with combined HRT use when compared with no HRT, and the risk increased with duration of use.
The committee agreed that, although both studies adjusted for many relevant confounders, neither adjusted for all. They concluded that the evidence might be at risk of bias from confounding.
They noted that the evidence was for all types of dementia. The risk for some types of dementia may be different to others, and the proportion of each type identified at follow-up may differ for each study. The committee thought this may explain some of the differences in risk.
Evidence from the WHIMS study on combined HRT compared with placebo was inconsistent with the observational evidence from the UK, but in line with that from Denmark (showing an increased risk in dementia in the HRT group). They also noted that the population was different from a typical group of people taking HRT, in that they first started taking HRT at age 65 or over.
The committee were not unanimous in their interpretation of the evidence and how to formulate a recommendation best reflecting the evidence base. Some members of the committee had concerns about highlighting a risk of dementia when evidence from a UK setting showed no difference in risk.
However, the committee reached a majority decision. Taking all evidence into account, they decided the evidence pointed towards a possible increased risk in dementia incidence if HRT is started at a later age. They agreed it was important that people thinking about HRT for menopause-associated symptoms should be made aware of this, so that they could make an informed decision.
As part of this, the committee:
-
chose to use the word 'might' to express uncertainty, given the differences between study results
-
agreed that it was important to highlight, based on the WHIMS evidence, the increase in risk that was noted when HRT was started over 65 years of age.
Recommendations for research
The committee recognised that there are still uncertainties around the current evidence base and that further research is needed. They noted that the previous version of the guideline included a recommendation for research related to dementia and decided to keep this.
The evidence was unclear about the impact of mode of administration on risk of dementia. The committee therefore prioritised a recommendation for research on mode of administration for systemic HRT.
How the recommendation might affect practice
It is current practice to discuss benefits and risks with people when thinking about treatment options. The recommendation will standardise and update the information that will be shared. While the 2024 version of this guideline includes some new or updated information to share, it is unclear how this will affect treatment choices and impact on practice.
It is possible that the recommendation may increase the use of transdermal HRT, given that it was not associated with an increased risk of stroke (and, according to 2015 recommendations that were not reviewed in 2024, it is also associated with a lower risk of venous thromboembolism than oral preparations).
Effect of oestrogen-only HRT on specific health outcomes in people aged 45 or over
Recommendation 1.6.3 and table 2
What this rationale covers
The committee agreed that people should be presented with a complete picture of benefits and risks associated with HRT to enable shared, and informed, decision making.
This rationale briefly describes the available evidence on oestrogen-only HRT and how it affects risks related to:
-
cancer: breast
-
cancer: endometrial
-
cancer: ovarian
-
coronary heart disease
-
stroke
-
dementia.
It also covers other considerations related to cardiovascular disease, and the need for further research in this area.
There was no evidence available for trans men and non-binary people registered female at birth. The committee agreed that their conclusion from the available evidence could be extended to those who have never taken gender-affirming hormone therapy. But they did not think it could be extended to those who have taken this type of therapy in the past, because it is not known whether such therapy would alter the benefits and risks of any management option (especially hormonal treatments), or which management option might be best for the person. So, they made a recommendation for research on the impact of HRT on health outcomes for these groups.
Combined and oestrogen-only HRT are prescribed to different groups of people, as per recommendation 1.8.1, and so the committee looked separately at the benefits and risks associated with the 2 types of HRT.
Why the committee made this recommendation
Cancer: breast
In line with other NICE guidance, the committee agreed that advice needs to be tailored to the person according to their individual risk factors, such as having a family history of breast cancer, living with overweight, or drinking alcohol. The committee acknowledged that people also need to be made aware that these factors will affect absolute risks of breast cancer both when not taking and when taking HRT.
The committee discussed evidence on the effect of taking HRT on breast cancer incidence and breast cancer mortality that came from:
-
randomised controlled trials (RCTs) and
-
a meta-analysis of individual patient data from observational studies.
Overall, it showed the risk of breast cancer incidence was consistently greater with combined HRT than with oestrogen-only HRT. Only women, trans men and non-binary people who have had a hysterectomy are eligible to take oestrogen-only HRT, so most people taking HRT will take combined HRT.
The committee discussed the evidence from the analysis of different durations of use of oestrogen-only HRT versus no HRT or versus placebo.
RCT evidence
RCT evidence showed a reduced risk in the incidence of breast cancer for women who are taking, or have taken, oestrogen-only HRT compared with women taking placebo. Women taking oestrogen-only HRT as part of the trial took it for approximately 6 years and were followed up for breast cancer for 7 years after the trial ended.
The evidence showed the risk was reduced regardless of ethnicity. There was insufficient data to detect whether having or not having a family history of breast cancer lead to a different level of breast cancer risk with oestrogen-only HRT.
Observational study evidence
Evidence from observational studies was not consistent with the RCT evidence but provided further information on the duration and recency of use. It showed that for women currently taking oestrogen-only HRT, the risk of breast cancer incidence:
-
was higher in those who had been taking HRT for at least 1 year and
-
increased with duration of use.
For women who had taken oestrogen-only HRT in the past, it showed the risk of breast cancer incidence:
-
was not quite as high as in those currently taking it
-
was greater the longer they had taken HRT
-
remained higher than for women who had never taken HRT for up to at least 10 years after stopping use.
Interpretation of the evidence on breast cancer incidence with oestrogen-only HRT
The committee decided that the difference between RCT results and evidence from observational studies meant that it was not possible to be certain of the conclusions. They also agreed this should be highlighted in the wording of the recommendation, by explaining that there was little or no increase in the risk of breast cancer incidence.
The committee also looked at evidence that compared different types of oestrogens and different modes of administration. The evidence did not show any differences in risk of incidence of breast cancer for different types of oestrogen. There was some uncertainty in relation to mode of administration. The committee therefore made a recommendation for research on mode of administration for systemic HRT.
Mortality from breast cancer
Evidence from an RCT showed that there was a reduction in the risk of mortality from breast cancer in those using oestrogen-only HRT compared with placebo. The observational data was not in line with the RCT data, as it showed there was an increased risk of mortality from breast cancer in oestrogen-only HRT users. The committee agreed that, although the RCT evidence showed a reduced risk, there was also evidence showing an increased risk. Therefore, it was important to highlight in the recommendations that there is a possibility of a small increase in the risk of breast cancer mortality.
Cancer: endometrial
The committee discussed the evidence from RCTs and observational studies. The evidence from RCTs was unclear because there were only 2 studies with no, or few, cases of endometrial cancer.
The committee also discussed the evidence from observational studies on oestrogen-only HRT versus no HRT in women with a uterus. It showed that the risk of endometrial cancer is increased in those:
-
currently taking oestrogen-only HRT and
-
who have been taking HRT for over 10 years (and are still taking it) or have taken oestrogen-only HRT in the past for over 10 years.
This increase in risk was present regardless of whether the treatment was oral or transdermal.
The committee discussed the well-established association between oestrogen-only HRT and the risk of endometrial cancer. They agreed it was important to explain to people with a uterus that this is why they would be offered combined HRT as per recommendation 1.8.1 in the section on starting HRT.
Cancer: ovarian
The committee discussed the evidence from observational studies. No evidence from RCTs was identified. Overall, with oestrogen-only HRT, the evidence showed that the risk of ovarian cancer:
-
was higher in those who had been taking HRT for at least 5 years
-
increased with duration of HRT use.
However, the committee agreed that risk remained small in absolute terms, because the baseline risk of ovarian cancer is low. The risk increased by 1 in 1,000 women for oestrogen-only HRT, when currently taking it, having started at the age of 50. The committee agreed that all of this should be explained when HRT is being considered.
Coronary heart disease
The committee based their recommendations on RCTs and observational studies.
The majority of the RCT and observational evidence both showed the risk of coronary heart disease did not increase when taking HRT. The committee agreed this information should be shared with people to allow them to make an informed decision.
The committee also discussed the evidence on the possible impact of 2 factors:
-
the length of time between menopause and the first use of HRT
-
the person's age at first HRT use.
They looked at coronary heart disease risk for different subgroups, and at the statistical significance of any differences observed between these subgroups. As a result, they agreed they could not make any recommendations about the impact of either of these factors on coronary heart disease risk in people taking HRT. This is because there were:
-
no statistically significant subgroup differences in the RCT evidence
-
inconsistent results between different observational studies and
-
inconsistency between the conclusions of the RCT evidence and observational studies.
RCT evidence
When looking at women of all ages at first HRT use together as 1 group, the evidence showed no difference in risk of coronary heart disease between women who had been taking oestrogen-only HRT for 5 to 9 years and were still taking it, and women who were not taking HRT and had never taken it.
Subgroup analysis that looked at whether coronary heart disease risk was affected differently (if at all) for people of different ages at first HRT use, showed:
-
an isolated reduced risk in 1 subgroup (when people were 50 to 59 at first HRT use) but
-
no difference in risk for any of the other subgroups.
In addition, statistical testing showed that the difference between people aged 50 to 59 at first HRT use and other subgroups was not significant and so should not be included in information shared with people considering HRT.
Observational study evidence
The committee looked at observational evidence on whether the length of time between a person's menopause and the moment they start HRT affects their risk of coronary heart disease. For women currently taking oestrogen-only HRT, who had been taking it for an unknown duration, the 2 observational studies reported different conclusions on this:
-
One study showed a reduced risk of coronary heart disease when HRT was started within 4 years of menopause, while the other study showed no difference in risk when HRT was started between the ages of 45 to 54 (which is likely to be within 4 years of menopause).
-
One study showed no difference when HRT was started more than 10 years after menopause, while the other study showed a reduction in risk when HRT was started between the ages of 65 and 74 (which is likely to be 10 years or more after menopause).
The committee recognised that some observational studies may have been influenced by residual confounding factors such as socioeconomic status, smoking, medical history or other factors which may be related to HRT use and cardiovascular risk.
Differences in direction of effect across study types
When looking at the effect of age at first use of HRT on the risk of coronary heart disease, there was also some variation in results across different study types, for example:
-
the RCT evidence showed no difference in risk when HRT was started between the ages of 60 and 69
-
an observational study showed a reduction in risk when HRT was started between the ages of 65 and 74.
The age groups overlap between the RCT and observational study, but the results for these overlapping age groups are contradictory, making it difficult to reach a conclusion with regards to age trends.
Stroke
The committee based their recommendations on RCTs and observational studies.
The RCTs showed that, overall, there is an increased risk of stroke in women currently taking oral oestrogen-only HRT. These findings were supported by observational evidence. National statistics also show that the baseline risk for stroke in women aged under 60 is very low. The committee agreed that this should be explained to anyone thinking about HRT because the risk may remain small despite any change in risk reported in the RCT and observational study findings.
Observational evidence showed that transdermal oestradiol did not increase the risk of stroke whereas oral oestradiol did. The committee noted that this was consistent with the pattern in combined HRT. They agreed that this should be explained so that people can factor this into their decision making.
The observational evidence showed an increased risk of stroke when oestrogen-only HRT was given at a high dose while, at low and medium doses, there was no increase in risk for oestrogen-only HRT compared with no HRT. Risk was also increased in women currently taking oestrogen-only HRT who had been taking it for 5 to 9 years when they had been aged 60 years or over at first HRT use. The committee decided that both these points should be covered when making shared decisions on treatment.
Impact of timing of HRT for menopause symptoms on risk of coronary heart disease
There was not a lot of data to check whether the following factors impact on risk of coronary heart disease:
-
the age of the person when they start HRT and
-
the time between a person's menopause and when they start HRT.
This resulted in what is called 'lack of statistical power'. In other words, the small amount of data means that statistical test could show a difference where there is none.
In what little data was available, the risk did not have a clear tendency to decrease or increase with either of the above 2 factors (that is, with the age of the person when they start HRT or the time between a person's menopause and when they start HRT).
As a result, the committee decided to make a recommendation for research on the impact of timing of HRT on risk of coronary heart disease.
Impact of mode of administration of oestrogen-only HRT on coronary heart disease
There was no evidence on whether 1 mode of administration of oestrogen-only HRT differed to another in its impact on risk of coronary heart disease. The committee therefore prioritised a recommendation for research on the mode of administration for systemic HRT.
Risk of cardiovascular disease with HRT in people from ethnic minority backgrounds
The committee noted that there was little evidence for people from ethnic minority backgrounds for cardiovascular health and stroke (as well as all other health outcomes), so they made a recommendation for research on the impact of HRT on health outcomes for these groups of people.
Other considerations relating to cardiovascular disease
The committee were aware of systematic reviews by Boardman et al. (2015), Kim et al. (2020) and Salpeter et al. (2006) – see the list of excluded studies in evidence review C: cardiovascular disease and stroke. These 3 systematic reviews did not meet the inclusion criteria of NICE's 2024 evidence review because:
-
they combined data for participants who received combined HRT and oestrogen-only HRT (Boardman et al. 2015) or
-
some individual studies included within a review did not match NICE's 2024 criteria and therefore the entire systematic review could not be included (Kim et al. 2020 and Salpeter et al. 2006).
The studies included in these systematic reviews were checked and any relevant ones were then included in NICE's 2024 evidence review if they matched its criteria.
However, the committee did comment on whether the conclusions made in NICE's 2024 evidence review aligned with the findings of these 3 systematic reviews. Although there were differences observed in certain areas, none of them challenged the overall conclusion that HRT does not increase coronary heart disease risk.
Dementia
The committee noted that there was relatively little evidence on dementia compared with other health outcomes, with only 7 studies identified. They acknowledged that most of the evidence was from observational studies and so they very carefully looked at how various confounders had been adjusted for.
The committee agreed that some of the evidence did not make the necessary adjustments for confounding factors, such as socioeconomic status, or did not reliably ascertain incidence of dementia.
To guide their discussions and support the recommendations, the committee agreed to focus on 2 observational studies, 1 from the UK and 1 from Denmark (which both made the most appropriate adjustments for confounders). They also focused on the Women's Health Initiative Memory Study (WHIMS) of women starting HRT over the age of 65, which is based on data from a randomised controlled trial (RCT) from the Women's Health Initiative (WHI).
The observational evidence showed no significant differences in dementia risk when comparing oestrogen-only HRT with no HRT use. The evidence from the WHIMS study also showed no significant differences in incidence of dementia, between those who are taking or have taken oestrogen-only HRT and those taking placebo.
The committee discussed some of the limitations in the WHIMS study, such as the low incidence of dementia in the placebo arm, which was lower than the incidence of dementia in the UK. They also noted that the population was different from a typical group of people taking HRT, in that they first started taking HRT at the age of 65 or over.
Recommendations for research
The committee recognised that there are still uncertainties around the current evidence base and that further research is needed. They noted that the previous version of the guideline included a recommendation for research related to dementia and decided to keep this.
The evidence was unclear about the impact of mode of administration on risk of dementia. The committee therefore prioritised a recommendation for research on mode of administration for systemic HRT.
How the recommendation might affect practice
It is current practice to discuss benefits and risks with people when considering treatment options. The recommendation will standardise the information that will be shared. While the 2024 version of this guideline includes some new or updated information to share, it is unclear how this will change the treatment choices made and how this will impact on practice.
It is possible that the recommendation may increase the use of transdermal HRT since it was not associated with an increased risk of stroke (and, according to 2015 recommendations that were not reviewed in 2024, it is also associated with a lower risk of venous thromboembolism than oral preparations).
Cardiovascular disease prevention
Why the committee made the recommendation
Given the findings about the effect of HRT on coronary heart disease and stroke (as covered in the rationales on the effect of combined and of oestrogen-only HRT) the committee agreed that the evidence did not support the use of combined or oestrogen-only HRT for primary or secondary prevention of cardiovascular disease.
How the recommendation might affect practice
It is unclear whether it is current practice to use HRT for the specific purpose of primary or secondary coronary heart disease prevention. So, the recommendation is likely to standardise practice.
Dementia prevention
Why the committee made the recommendation
The committee noted the scope of this guideline and agreed that the indication for HRT prescriptions in the UK was menopause symptoms. Therefore, the aim of the included studies was not dementia prevention. They agreed it was important to highlight that the evidence did not support this indication.
How the recommendation might affect practice
It is unclear whether it is current practice to use HRT for the specific purpose of dementia prevention. So, the recommendation is likely to standardise practice.
Effects of HRT use in early menopause on specific health outcomes
Why the committee made the recommendation
No evidence was identified on the benefits and risks of either taking or not taking HRT relating to osteoporosis, risk of fractures or cardiovascular outcomes, or endometrial or ovarian cancer in people experiencing early menopause (people aged 40 to 44). Some evidence was identified on the effect of taking or not taking HRT on breast cancer risk in this age group.
The committee did not look at evidence on whether early menopause itself may have an impact on health outcomes, and how to manage any impact it might have. Therefore, they could not make any recommendations on the benefits and risks of HRT to manage any differences in risk that may result from early menopause.
The committee agreed it was important to take a person's age at the onset of menopause-associated symptoms into account during discussions about HRT (in line with the section on discussing management options). They agreed that the age cut-offs defining premature ovarian insufficiency (POI), early menopause and typical menopause were a little arbitrary. They also agreed it is clinically plausible that the benefits and risks evolve gradually from what they are for people with premature ovarian insufficiency to what they are for people aged 45 or over. As a result, it is likely that, for people with early menopause, the benefits and risks of either taking or not taking HRT lie somewhere between those for people with premature ovarian insufficiency and those for people aged 45 or over, for whom there is more evidence about these benefits and risks.
The committee discussed the similarities between early menopause and POI. Although there is little evidence of the impact of HRT on health outcomes in people with POI, it is current practice for this group to take HRT routinely. HRT is offered to them to lower the risk of some health outcomes, for example, osteoporosis. The situation may be similar for early menopause, for which routine HRT is also current practice.
Evidence showed that, as for people aged 45 or over, the risk of breast cancer in early menopause is increased when taking HRT compared with not taking HRT. However, the committee agreed that taking HRT in early menopause may affect the risk of different health outcome in different ways (that is, it may decrease some risks and increase others), as it does for people with POI and for people experiencing menopause at 45 or over.
As a result, the lack of evidence on outcomes other than breast cancer meant that it was not possible to make recommendations about the overall balance of benefits and risks of taking or not taking HRT in early menopause.
The committee agreed that it was important to highlight this lack of evidence and made a key recommendation for research on the impact of HRT in early menopause on specific health outcomes to address it.
How the recommendation might affect practice
While the recommendation may help people make decisions about treatment, it is unclear how it will change these decisions and how that will impact overall resource use. It would however be unethical to prevent such information being discussed with people experiencing early menopause even if it did lead to an increase in resource use.
Starting and stopping HRT for anyone
Recommendations 1.8.1 to 1.8.3 and 1.8.7
Why the committee made the recommendations
Starting HRT
When a person decides they want to take HRT for menopause-associated symptoms, the committee recommended, that, if the person has a uterus, they should be offered combined oestrogen and progestogen. Whereas, if the person has had a total hysterectomy, they should be offered oestrogen alone.
The main reason for this is the established knowledge that oestrogen alone, if given to people with an intact uterus, can stimulate the growth of the uterine lining (endometrium). In turn, this oestrogen stimulation can lead to an increased risk of endometrial hyperplasia (overgrowth of the endometrium) and potentially, endometrial cancer.
This is consistent with the evidence showing that oestrogen-only HRT increases the incidence of endometrial cancer in people with a uterus (see the section related to the effect of oestrogen-only HRT on endometrial cancer for people aged 45 and over). However, because it is now considered unsafe to give oestrogen-only HRT to people with a uterus, no further research is being carried out, and the recommendation is based on established knowledge more than on the evidence identified for this guideline. Adding progestogen to the HRT regimen helps protect the endometrium by counteracting the stimulating effects of oestrogen, and so reduces the risk of endometrial hyperplasia and cancer.
Progestogen is given to protect the uterine lining, so it is not needed for people who have had a total hysterectomy. The committee discussed that this may be different for people with a subtotal hysterectomy. They decided that they could not be prescriptive about the type of HRT to be used for people who have had a subtotal hysterectomy because their condition is clinically complex, and they had not reviewed evidence about the effect of HRT on risk of endometrial cancer for this group. They acknowledged that people who were going to have, or had had, a subtotal hysterectomy would likely be under the care of a specialist (or a relevant member of the associated multidisciplinary team) who could discuss HRT options tailored to their needs.
Some people have a hysterectomy for a condition that may be affected by HRT, such as endometriosis. The committee did not review evidence related to such conditions. However, they recognised that the decision about the type of HRT that best balances benefits and risks for a person who has had a hysterectomy may be affected by the condition that led to the hysterectomy. For this reason, advice from a healthcare professional with specialist knowledge of that condition may be needed.
The committee noted that it is common practice to prescribe the smallest effective dosage of a treatment to help balance its benefits and risks, so they recommended this for HRT too. Effectiveness of HRT can vary between people, so starting with the lowest effective dosage helps find the right balance between effectively treating symptoms and managing risks from the treatment, taking into account each person's specific needs.
Stopping HRT
A personal history of cancer is a contraindication to systemic HRT because it has been shown that systemic HRT can lead to cancer progression or recurrence. Therefore, the committee agreed that systemic HRT should be stopped in people who are diagnosed with breast cancer because this would be off-label use and therefore there would be safety concerns. However, they agreed that this is already covered in NICE's guideline on early and locally advanced breast cancer.
How the recommendations might affect practice
The recommendations reflect current practice in choice of HRT prescribing for people with a uterus or for people who have had a total hysterectomy.
It is common practice to seek advice from a healthcare professional with expertise in a condition when the clinical situation is complex, such as identifying the most suitable type of HRT for someone whose condition may be affected by it. This would usually be an informal process, so it is unlikely to have a significant impact on practice.
Stopping HRT if a person is diagnosed with breast cancer is also current practice.