Scientists develop quick, cheap spit test for prostate cancer | Prostate cancer

Scientists have developed a spit test that could “turn the tide” of prostate cancer worldwide by detecting the disease earlier, detecting where men are at high risk and sparing others from unnecessary treatment.

The number of men diagnosed with prostate cancer worldwide is expected to double to 2.9 million per year by 2040, and annual deaths are expected to increase by 85%. It is already the most common form of male cancer in more than 100 countries.

Early diagnosis is crucial, but experts say current standard blood tests for PSA can go undetected in men with cancer and force others to undergo unnecessary treatments or undergo unnecessary additional checks and exams .

Now researchers from the Institute of Cancer Research in London (ICR) and the Royal Marsden NHS Trust appear to have found a better alternative.

A study shows that their new saliva test, which involves taking a DNA sample in seconds, is more accurate than the current standard blood test. The results will be presented this weekend at the world’s largest cancer conference.

“With this test, it may be possible to reverse the trend in prostate cancer,” said Ros Eeles, professor of oncogenetics at ICR. “We showed that a simple, inexpensive spit test, which can identify men at higher risk due to their genetic makeup, is an effective tool for detecting cancer at an early stage.”

Speaking at the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago, Eeles said the breakthrough came after decades of research into genetic markers of the disease.

“Our study shows that the theory works in practice: we can identify men at risk for aggressive cancers who need additional testing, and spare low-risk men from unnecessary treatments.”

Scientists and doctors developed the spit test after studying the DNA of hundreds of thousands of men. It works by looking in saliva for genetic signals linked to prostate cancer.

In the Barcode 1 trial, researchers recruited more than 6,000 European men to test the spit test. All were recruited from their GP practice and were aged between 55 and 69 – an age at which the risk of prostate cancer is increased.

Once the saliva was collected, the test calculated each man’s polygenic risk score (PRS). The score is based on 130 genetic variations in the DNA code linked to prostate cancer.

In people at highest genetic risk, the test gave fewer false positives than the PSA test, detected people with cancer who would not have been detected by the PSA test alone, and detected a higher proportion aggressive cancers than the PSA test. » said the ICR.

The test also accurately identified men with prostate cancer that had not been detected by an MRI.

Dheeresh Turnbull, 71, from Brighton, was one of the first men in the world to attempt the spit test and discovered he had prostate cancer when he got the results.

He said: “I was completely shocked when I received my diagnosis as I had absolutely no symptoms, so I know I would never have been diagnosed at this stage if I hadn’t taken part in the test. »

Turnbull underwent robotic surgery to remove part of his prostate and is doing well.

He said: “Because the saliva test revealed that I had a high genetic risk of developing the disease, my younger brother, who would have been too young to take part directly in the study, signed up and discovered that He also had an aggressive tumor in his prostate. It’s incredible to think that because of this study, two lives have now been saved in my family.

Eeles, a consultant in clinical oncology and cancer genetics at the Royal Marsden NHS Foundation Trust, warned that further research would be needed before the test could be widely rolled out.

“Our next step will be to test the genetic markers we have identified that are associated with prostate cancer risk in diverse populations, to ensure this test can benefit all men.”

Population aging and increasing life expectancy mean that the number of older men living longer around the world is increasing. Since the main risk factors for prostate cancer – such as being 50 or older and a family history of the disease – are unavoidable, experts say it will be impossible to prevent the increase in cases. simply through lifestyle changes or public health interventions.

However, better testing and earlier diagnosis could help reduce the burden and save lives.

“Cancers detected early are much more likely to be curable,” said Professor Kristian Helin, director general of the ICR. “And with prostate cancer cases expected to double by 2040, we need to put in place a program to diagnose the disease at an early stage.

“We know that the current PSA test can force men to undergo unnecessary treatment and, more worryingly, it is missing men with cancer. We urgently need an improved test to detect the disease. This research is a promising step toward this goal and highlights the role that genetic testing can play in saving lives.