According to the findings of a recent study, men who have been diagnosed with aggressive prostate cancer that has spread (metastasized) into other areas of the body may want to consider getting a genetic test to get the same benefits. Men with metastatic prostate cancer appeared significantly more likely to harbor germline mutations in DNA repair genes than those with localized disease, according to data published in The New England Journal of Medicine. The frequency of germline mutations in men with prostate cancer — which did not differ according to age at diagnosis or family history of prostate cancer — suggests a need for routine genetic testing in this population.
In a study involving 692 men with advanced prostate cancer that had spread, researchers led by Dr. Peter Nelson at the Fred Hutchinson Cancer Research Center looked at 20 genes known to be involved in DNA repair. These genes are highly associated with prostate cancer risk. If Nelson and his team found more mutations in these genes among men with metastatic prostate cancer, then that would suggest that these genes are good predictors of more aggressive cancer. The rate of mutations in these genes was nearly 12% among these men, compared to about 5% among men with slower growing, localized prostate cancer.
“The result is surprising and important for men with prostate cancer, as this information may prioritize certain therapies. It is also important for family members, as they may have inherited a gene that predisposes them to developing one of several types of cancer and heightened awareness could enhance early detection and treatment. These findings present a compelling argument for updating prostate cancer guidelines to include germline DNA testing as a part of standard care for men with metastatic prostate cancer.”
-Peter Nelson, MD
BRCA2 was the most common gene found, which was mutated in 5% of men. The study therefore contemplates the possibility of starting to carry out tests on relatives for BRCA2 mutations. These markers could increase survival for many diagnosed with prostate cancer by narrowing down the severity of the cancer. More studies are needed to confirm whether mutated DNA repair genes could help in predicting how a disease will run, the scientists said. But in the future, it might be a big help in identifying which men with prostate cancer have the more aggressive type and which have the slow-growing type, to inform patients if they need more screening and medications, and how much monitoring should be conducted.
For now, says Nelson and his team, the test should be part of any man’s care if he is diagnosed with advanced prostate cancer. “We’re definitely advocating for all men with metastatic prostate cancer to have this testing,” he says. “The frequency of 12% is a reasonably high enough hit rate to support that kind of testing.” The question as to whether insurance companies will cover the cost of the testing is another issue entirely, but with results such as these it may help to change national guidelines to include this test for men, and as a result may help inspire insurers to cover said costs.