Genetic test that analyzes DNA to identify men at greatest risk for developing the disease could become common clinical laboratory screen for cancer
Researchers in the UK believe a common spit test can be more accurate at determining which men are more likely to develop prostate cancer than the clinical laboratory prostate-specific antigen (PSA) blood test currently used by the National Health Service (NHS) for that diagnosis.
During a recent study, scientists at the Institute of Cancer Research, London (ICR), found that germline DNA extracted from saliva, which was then used to derive polygenic risk scores for cancer, resulted in a higher percentage of participants “found to have clinically significant disease” than the percentage that would have been identified with the use of PSA or MRI.
They published those findings and others in the New England Journal of Medicine.
The salvia test works by analyzing men’s DNA to find out if they are genetically pre-disposed to developing the disease. Men who find out they are likely to develop prostate cancer can then pursue further testing and scans.
“The test assesses 130 genetic variants to provide a risk score for prostate cancer, which is the second most common cause of cancer deaths in men in the UK,” The Guardian reported.
The study found that 187 of the men in the study had prostate cancer. According to the American Cancer Society, one in eight men will be diagnosed with prostate cancer in their lifetime.
“We can identify men at risk of aggressive cancers who need further tests and spare the men who are at lower risk from unnecessary treatments,” said study leader Rosalind Eeles, PhD, of the ICR London, in The Guardian.
“With this test, it could be possible to turn the tide on prostate cancer,” Rosalind Eeles, PhD, of the Institute of Cancer Research, London, told the BBC. (Photo copyright: Prostate Cancer UK.)
Landmark Discovery
Michael Inouye, PhD, professor of systems genomics and population health at the University of Cambridge, told the BBC that researchers will look back on this study “as a landmark.” He also acknowledged that it would be a long road before widespread implementation of the test.
While some sources call the ICR’s test promising, they also acknowledge it may only have a modest effect and that there may be possible racial disparities in the findings. The study was primarily based on people with European ancestry. According to Prostate Cancer UK, black men in the UK have double the risk of developing the disease. A similar trend can be observed in the US, Statistica reported.
Dusko Ilic, PhD, professor in stem cell sciences at King’s College London, told the BBC that there was “no direct evidence” of these findings having an effect on survival or quality of life. He stressed the need for more studies to better assess the value of the test.
The salvia test is expected to be included in Prostate Cancer UK’s TRANSFORM trial, a $58 million research program partly funded by the NHS to determine the best way to screen for cancer in the UK.
Effect on Clinical Pathologists
Prostate cancer is expected to surge in the US over the next 15 years, according to UC Davis Health. Thus, pathologists should expect more men to seek ways to assess their risk. Pathologists would be wise to educate themselves fully on new and emerging tests and tools to best meet the needs of their patients.
Given the publicity generated by former President Biden’s announcement that he has an advanced case of prostate cancer, clinical laboratories should also expect more patients to request diagnostic tests that either screen for or confirm the presence of the disease.
—Ashley Croce
