A recent study has found that examining saliva by spitting into a test tube at home is better than a blood test for identifying men with a high genetic risk of developing aggressive (i.e., fast-spreading and more difficult-to-treat) prostate cancer.
The study was conducted by researchers from the Institute of Cancer Research in London and the Royal Marsden Foundation of the British National Health Service, and the preliminary results were presented at the annual meeting of the American Society of Clinical Oncology in Chicago, USA, which was held between May 31 and June 4. This June, the British newspaper The Independent wrote about it.
Prostate-specific antigen test
The blood test used to detect prostate cancer is the prostate-specific antigen (PSA) test. This antigen is a protein made only by the prostate gland. Some of it leaks into the blood, but its amount in the blood depends on age and the health of the prostate.
A high level of prostate-specific antigen in the blood may be a sign of prostate cancer, but it may also be a sign of a condition other than cancer, such as an enlarged or inflamed prostate or a urinary tract infection.
The prostate-specific antigen test is a blood test to help detect prostate cancer, but it is not a perfect test and will not detect all types of prostate cancer.
The test, which can be done in a GP surgery, measures the level of prostate-specific antigen in the blood.
Saliva test
In contrast, the saliva test (the subject of the new study), which can be sampled at home, looks for genetic variants associated with prostate cancer.
Researchers at the Institute of Cancer Research in London and the Royal Marsden Foundation of the National Health Service told the newspaper that for men with a high genetic predisposition to the disease, saliva analysis was more accurate than the prostate-specific antigen test as an early assessment tool.
The team said their research could help bring about a paradigm shift in prostate cancer by providing a cheap, easy-to-use saliva test to detect the disease early and save thousands of lives.
The team found that the saliva test gave fewer false positive results and detected a higher proportion of aggressive cancers than the PSA blood test.
Professor Christian Heylen, CEO of the Cancer Research Institute, told the newspaper that cancer cases that are detected early are likely to be curable, and with prostate cancer cases doubling by 2040, we must have a program to diagnose the disease early.
He added that they know that the current prostate-specific antigen test can cause men to undergo unnecessary treatments, and what is most worrying is that it may not detect men with cancer, indicating the urgent need for improved testing to detect the disease.
As for the new test, he pointed out that this research is a promising step towards this goal, and it highlights the role that genetic tests can play in saving lives.