An innovative saliva test offers hope for the early detection of prostate cancer. It promises more precise results than conventional methods.
Prostate cancer is the most common cancer in men in Germany. Scientists have now developed a saliva test that has the potential to improve the treatment of this cancer worldwide by detecting the disease earlier and better identifying men at high risk.
The test could therefore save many men from unnecessary biopsies and treatments. The method was developed by researchers at the Institute of Cancer Research, London (ICR) and the Royal Marsden NHS Foundation Trust.
Early detection with current method is inaccurate
Prostate cancer is already the most common type of cancer in men in many countries. And according to the ICR, the number of prostate cancer cases is expected to double by 2040. Prostate cancer is easily treatable if detected early. Early detection is therefore crucial.
The problem: The current method, the so-called PSA blood test, is often inaccurate and can also lead to overdiagnosis (false positive results) and unnecessary surgery in some men. Read more about why the current PSA test can lead to unnecessary biopsies and side effects such as impotence.
Info: What does PSA mean?
PSA stands for prostate-specific antigen: This is a protein that the prostate produces and which also passes into the blood in small amounts. Since cancer cells produce more PSA than healthy cells, an increased PSA level can indicate prostate cancer. However, other factors can also cause the PSA level to rise, such as inflammation, cycling or benign prostate enlargement.
Researchers at the Institute of Cancer Research (ICR) in London and the Royal Marsden NHS Foundation Trust may have found a better alternative. Their study shows that their new saliva test, which takes a DNA sample in a few seconds, is more accurate than the current standard blood test. The results were presented this weekend at the world's largest cancer conference.
DNA from saliva leads to reliable early detection
For their saliva test, scientists and doctors examined the DNA of hundreds of thousands of men. The test works by looking for genetic signals in people's saliva that, according to current knowledge, are linked to prostate cancer.
In the so-called Barcode-1 study, researchers recruited more than 6,000 European men aged between 55 and 69 who are at increased risk of prostate cancer. After collecting saliva, the test calculated each man's so-called polygenic risk score (PRS), which is based on 130 genetic variations in the DNA code that are associated with prostate cancer.
- In men with the highest genetic risk, the test produced fewer false positive results than the PSA test.
- The test identified men with cancer who would have been missed by the PSA test alone.
- The test detected a higher proportion of aggressive cancers than the PSA test.
- The test also identified men with prostate cancer who had been missed by an MRI scan.
Test is a breakthrough after decades of research
“With this test, it may be possible to win the battle against prostate cancer,” said Ros Eeles, Professor of Oncogenetics at the ICR. “We have shown that a simple, inexpensive saliva test that identifies men at higher risk based on their genetic predisposition is an effective means of early detection of cancer.” 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 the 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 further testing and spare those at lower risk from unnecessary treatment.”
Prevention: Lifestyle changes are not enough
However, Professor Eeles of the ICR warned that further research is needed before the test can be used widely. “Our next step will be to test the genetic markers we have identified that are associated with a risk of prostate cancer in different population groups.” This will ensure that this test can benefit all men.
One thing is clear: As life expectancy increases, the number of older men worldwide is increasing. And age is a major risk factor for prostate cancer, as are genes. Experts therefore believe that it will be impossible to prevent the rise in cancer cases through lifestyle changes or public health measures alone. However, better testing and earlier diagnosis could help reduce the burden and save lives.
