.
Image: The container to collect saliva in at home. Credit: Zsofia Kote-Jarai, The Institute of Cancer Research, London
Thousands of men could have their prostate cancer diagnosed at an earlier stage when it is easier and cheaper to treat, thanks to a new spit test which can be taken at home.
An innovative new study launched this week, led by researchers at The Institute of Cancer Research, London, is looking at whether the saliva test can speed up prostate cancer diagnoses and save the NHS money.
Identify 12,350 people earlier
In the coming year, more than 52,000 people will be diagnosed with prostate cancer. Up to one in four of these will be diagnosed at a later stage, requiring more extensive treatments which cost the NHS around £650 million.
The team estimates that their saliva test could identify up to 12,350 people earlier, saving the NHS around £500 million a year and saving lives.
Pick up people with high genetic risk
The research team have developed the test which calculates the risk of prostate cancer from DNA extracted from saliva – called a genetic risk score. GPs will offer the test to their patients, and those identified as higher risk will be offered prostate cancer checks.
The £2 million study, funded by the National Institute for Health and Care Research (NIHR) Invention for Innovation (i4i) Early Cancer Diagnosis Clinical Validation and Evaluation programme, aims to pick up more people with prostate cancer at an earlier stage – when it is more treatable.
Recent research from the same team showed that a simple saliva test was more accurate at identifying future risk of prostate cancer for men at higher-risk than the current standard blood test, which measures levels of a protein called prostate-specific antigen (PSA).
Now, they have developed an updated version of the test, called PRODICTTM, which looks for more genetic variants that indicate cancer than the original test – more than 400 genetic variants, which are both commonly occurring and rare.
Used in diverse populations
The study aims to recruit 1,000 people with prostate glands – men, non-binary people and trans women – from diverse ethnic groups, aged between 40 and 55 years.
The original saliva test could only be used for people of European ancestry as the genetic data weren’t available for men of Asian, African, or Black African-Caribbean ancestry, despite Black men being twice as likely to develop the disease.
The team at The Institute of Cancer Research (ICR) will follow the participants for three years to see if they develop prostate cancer and assess if these cancers are picked up earlier than usual. They will also evaluate whether the test is cost-effective, and any barriers to implementing it into primary care.
'Revolutionise healthcare'
Professor Ros Eeles, Professor of Oncogenetics at The Institute of Cancer Research, London, and Consultant in Clinical Oncology and Cancer Genetics at The Royal Marsden NHS Foundation Trust, said:
“With our simple to collect, at-home, spit test, we hope not only to extend the lives of people diagnosed with prostate cancer, but also save the NHS a significant amount of money.
“Too many men are diagnosed with prostate cancer at a late stage, when it is less likely to be curable and requires intensive, expensive, treatment. We desperately need a screening programme for prostate cancer that picks up the men at risk of aggressive cancers who need further tests, but spares the men who are at lower risk from unnecessary treatments.
“In men of European heritage, we’ve shown that identifying men at higher risk due to their genetic makeup is an effective tool to catch the cancer early. Now, we’re excited to be able to roll out our test to diverse populations – as Black men are twice as likely to develop prostate cancer – and younger groups, as those with a genetic predisposition are more likely to be diagnosed at younger ages.
“If our PRODICTTM test is successful, it could revolutionise healthcare as the first of many saliva tests provided to patients in primary care for a range of diseases, identifying people who will need further treatments by looking for variants in their DNA.”
Reduce health inequalities
Dr Zsofia Kote-Jarai, Senior Scientist at The Institute of Cancer Research, London, who developed the PRODICTTM test, said:
“We have uncovered hundreds of rare and common genetic variants that are linked to prostate cancer – some of these are linked specifically to aggressive disease, and some are found only in men with African ancestry.
“Putting these pieces of the jigsaw together, we now have a much better picture of the genetic causes of prostate cancer – and we’ve developed a simple and cheap test to identify those at higher risk.
“I hope that our PRODICTTM test will play an important role in reducing health inequalities men face, as Black men are twice as likely to develop prostate cancer but are too often diagnosed later.”
Professor Peter Johnson, The OLS Cancer Programme Chair and NHS England National Clinical Director for Cancer, said:
"We know that if we are to improve people’s chances of overcoming cancer we need to find better ways to detect and diagnose it as early as possible. The UK Government’s Cancer Programme, delivered by OLS, is investing in a range of promising technologies to expand our research in this field. The projects we are funding with the NIHR will accelerate the progress from the laboratory into clinical testing, to make sure the UK is exploring all the potential in our Life Sciences sector to help patients and support new inventions."
'Incredibly grateful'
Ian Mason, 66, from Oxfordshire was diagnosed with prostate cancer in April , four years after joining the team's earlier trial into the saliva test.
“I was referred by my GP to join the study four years ago and following a saliva test I was told I was in the top 10% percent for risk of developing prostate cancer. No one in my family has had the disease and my PSA score was low, so I was really shocked.
“Whilst on the trial I had yearly PSA tests and MRI scans and in April I received the news that I had prostate cancer. Shortly after my diagnosis I was treated with surgery at The Royal Marsden, and I have since been recovering well. I’m incredibly grateful that due to the simple saliva test my risk was identified and I was closely monitored, and I was therefore diagnosed at a treatable stage.”