For the study — presented Feb. 16 at the 2017 Genitourinary Cancer Symposium in Orlando, Florida — researchers examined the detailed family history of 605 prostate cancer patients at Tulane Cancer Center in New Orleans. Of the group, 147 patients had a family history that met National Comprehensive Cancer Network guidelines. Those men then received a commercially available genetic test from Invitae to identify and characterize pathogenic mutations related to defects in the DNA repair mechanism.
Researchers found a pathogenic variant in a cancer-related gene in about 16.3 percent of patients, a variant of unknown significance in 40.8 percent of patients, and no significant mutations in 42.9 percent of patients.
“Genetic testing of family members can help identify those at risk earlier and enable physicians to provide more proactive care,” Oliver Sartor, MD, one of the study’s authors, said in a press release. “Given small family sizes and a frequent lack of information about relatives, we suspect that broader genetic testing of prostate cancer patients may be warranted, beyond what current guidelines recommend, as mutations may be found in patients without a known family history of cancer.”
The study adds to the growing body of evidence that genetic testing (for BRCA1 and BRCA2, for instance) in DNA-repair genes can affect men and their families. If a man has a mutation, his close relatives might also be at increased risk of having that mutation and thus developing prostate and other cancers.
“Our understanding of the role of genetic changes in influencing a man’s risk of developing prostate cancer has deepened, just as it has for a woman’s risk for breast and ovarian cancer,” said Robert Nussbaum, MD, Invitae’s chief medical officer. “We also know genetic information can help predict which men are more likely to develop aggressive disease.”
Nussbaum added that “through cascade testing in families, finding the first such mutation in a man with prostate cancer can alert other relatives — men and women — of a substantially higher risk for breast, ovarian, prostate and pancreatic cancer. Finally, there is the possibility of providing better personalized therapies for those with this potentially lethal disease by highlighting treatments that target tumors deficient in homologous