Advice
The technology
The technology
trublood-prostate (Datar Cancer Genetics) is a diagnostic test that uses immunocytochemistry to diagnose prostate cancer from blood samples of people with suspected symptoms of cancer. It uses circulating tumour cells (CTCs) or circulating ensembles of tumour-associated cells (C-ETACS) that are isolated from blood samples and treated through a negative enrichment technique. Harvested CTCs are then characterised by immunocytochemistry profiling specific to primary prostate adenocarcinoma (positive to alpha-methylacyl-CoA-racemase [AMACR] and prostate-specific membrane antigen [PSMA] antibodies and negative to p63 antibodies). Studies have shown that these immunohistochemical antibodies can be used by urological pathologists in cases when light microscopic findings of a biopsy are unclear (Ross et al. 2020; Magi-Galluzzi 2018). AMACR-positive cytoplasmic staining is expressed by about 80% of limited prostatic adenocarcinoma on needle biopsy (Magi-Galluzzi 2018). PSMA positive staining is seen in over 90% of prostatic adenocarcinomas on needle biopsy (Tsourlakis et al. 2015). Test results take 8 days. Depending on the test result people will be classed as either low risk with prostate biopsy not recommended or high risk with prostate biopsy recommended.
Innovations
trublood-prostate is the first in vitro diagnostic test based on C-ETACS and CTCs isolated from blood samples. It is a non-invasive test. Currently, people with symptoms of prostate cancer and a high prostate-specific antigen (PSA) test result for their age are referred for a multi-parametric MRI (mpMRI). Depending on the result of the mpMRI, people are referred for an invasive procedure such as prostate biopsy to get a definitive diagnosis. trublood-prostate aims to avoid a biopsy, or flag it up, in addition to mpMRI test. The company claims that the potential test benefits would be reducing unnecessary invasive procedures and hospital visits. It claims its technology has an accuracy to detect prostate adenocarcinoma of 99.50%, a sensitivity of 100% and a specificity of 99.33%. These accuracy data are from unpublished company evidence for validation of the trublood-prostate diagnostic test.
Current care pathway
People with suspected prostate cancer are offered a blood test that looks for raised PSA levels. If these are raised, NICE's guideline on prostate cancer recommends offering mpMRI as the first-line investigation and reporting the results using a 5‑point Likert scale. Different biopsies are offered depending on the results of mpMRI Likert scale. People whose mpMRI Likert score is 1 or 2 could opt out or opt in for a systematic prostate biopsy after discussing the risk-benefit ratio of the procedure with a healthcare professional. People whose Likert score is 3 or more will be offered a mpMRI-influenced prostate biopsy. The method used for the biopsy can be either transperineal, when the needle goes through the skin between the testicles and the back passage, or transrectal ultrasound-guided biopsy (TRUS), when the needle goes through the wall of the back passage.
A TRUS biopsy is done using local anaesthetic. Usually, 10 to 12 small pieces of tissue from different areas of the prostate are sampled and it takes 5 to 10 minutes. A template transperineal biopsy is normally done under general anaesthetic. In this, 2 to 3 small pieces of tissue from 8 sites are sampled and it takes about 20 to 40 minutes. A mapping transperineal biopsy is not offered as part of an initial assessment, unless as part of a clinical trial.
The NHS rapid diagnostic and research pathways handbook for implementing a timed prostate cancer diagnostic pathway set out that, if appropriate, a prostate biopsy should be done within 9 days from GP referral and a target of 5 days turnaround for reported pathology should be agreed as a minimum standard. This is a 14‑day turnaround from GP referral to prostate biopsy result.
The following publications have been identified as relevant to this care pathway:
Population, setting and intended user
trublood-prostate is intended for use either in triaging people with suspected prostate cancer before having a conventional invasive prostate biopsy, or for diagnosing suspected prostate cancer in people who are not well enough to have a prostate biopsy.
trublood-prostate is for use in primary, secondary and tertiary care settings. The test can be done at the same time as a PSA test and is requested by a GP, urologist or oncologist by completing a trublood-prostate test request and consent form and then sending it to Datar Cancer Genetics in the UK.
Pre-specified quantity of pre-barcoded trublood-prostate collection kits can be stocked at the primary, secondary or tertiary care centre or provided on advance request (with at least 48 hours notice) from the company. The trublood-prostate collection kit contains vacutainer tubes, test requests and patient consent forms, sample collection instructions, sample packing and shipping instructions. Other materials needed but not provided are blood collection needles, single-use alcohol swabs and medicated dressings.
The blood samples (16 ml) collected are sent to the Datar Cancer Genetics laboratory in the pre-paid shipping package provided by the company. No additional specialist training on sample preparation is needed for staff in the blood test centre. The test result is sent back to the referring clinician by secure email and a hard copy sent by post. Test results take 8 days.
The company recommends that trublood-prostate results be used in addition to mpMRI to identify people with a high risk of cancer and to achieve diagnostic triaging for people in whom the diagnosis still needs confirmation by tissue biopsy.
Costs
Technology costs
trublood-prostate costs £750 per person (excluding VAT), including trublood-prostate collection kit and shipment.
Costs of standard care
According to the national schedule of NHS reference cost 2018/2019 a transrectal ultrasound-guided biopsy of prostate (LB76Z) costs £504 and a transperineal template biopsy of prostate (LB77Z) costs £1,413. mpMRI for prostate costs £215 (RD03Z). Cost of staff time and equipment needed to collect a blood sample is £4 (DAPS08, phlebotomy).
Resource consequences
The company states that the technology is currently not used in the NHS.
The company states that the adoption of trublood-prostate for diagnosing prostate cancer could avoid unnecessary biopsies and reduce travel time. There is no published evidence to support these claims.
No charge is made for samples that are not tested (for example, haemolysed or coagulated samples, samples damaged in transit, insufficient samples, delayed samples and samples with significant deviations in shipping conditions). The requesting hospital or GP clinic will receive an invoice for the test after the Datar Cancer Genetics laboratory has generated a result. No additional equipment needs to be purchased and therefore no maintenance or training is needed.