Notably, the ability of risk assessment, testing, and counseling to reduce cancer incidence and mortality among such women has not been directly evaluated by studies to date, said the review authors, led by Heidi D. Nelson, MD, MPH, of Oregon Health & Science University, Portland.
“Without effectiveness trials of intensive screening, practice standards have preceded supporting evidence,” said Dr. Nelson and coauthors noted in a report on the review findings.
In observational studies, mastectomy and oophorectomy have been associated with substantial reductions in subsequent cancer incidence and mortality; however, they are invasive procedures with potential complications, the authors noted.
“To determine the appropriateness of risk assessment and genetic testing for BRCA1/2 mutations as a preventive service in primary care, more information is needed about mutation prevalence and the effect of testing in the general population,” they added.
Researchers studying BRCA1/2 assessment as preventive service in primary care have generally looked at highly selected patient populations in referral centers, and have reported relatively short-term outcomes, they said.
Research is additionally needed on access to genetic testing and follow-up, effectiveness of risk stratification and multigene panels, and the impact of direct-to-consumer genetic testing, among other key questions, the authors of the review added.
Treatment implications
While the USPSTF recommendations do not mention systemic therapy, finding a BRCA mutation in a cancer patient today has important implications for treatment, said Rachel L. Yung, MD, and Larissa A. Korde, MD, MPH
Specifically, poly (ADP-ribose) polymerase (PARP) inhibitors have proved effective in certain BRCA-related cancers, Dr. Yung and Dr. Korde said in an editorial on the updated recommendations appearing in JAMA Oncology.
The Food and Drug Administration has already approved several PARP inhibitors for treatment of BRCA-linked metastatic breast or ovarian cancers, and studies are underway for other tumor types, including prostate and pancreatic cancers that harbor a BRCA mutation.
“Increasing awareness of BRCA mutation as a target for treatment will likely lead to an increase in the identification of patients with cancer harboring germline BRCA mutations, which in turn will increase the need for cascade testing for relatives of affected probands,” wrote Dr. Yung and Dr. Korde.
Addressing disparities in care
The USPSTF recommendations for BRCA risk assessment do not address disparities in testing referral and variation in breast cancer phenotypes among women of African ancestry, owing to lack of evidence, according to Lisa Newman, MD, MPH, of the Interdisciplinary Breast Program at New York–Presbyterian/Weill Cornell Medical Center, New York.
“Paradoxically, the data-driven basis for the USPSTF recommendation statement may magnify existing genetic testing disparities,” Dr. Newman wrote in an editorial that appears in JAMA Surgery.
Non-Hispanic black women in the United States have a twofold higher incidence of triple-negative breast cancer, which is a well documented risk factor for BRCA1 mutation carrier status, according to Dr. Newman.
Despite this, she added, genetic counseling and testing referrals remain “disproportionately low” among U.S. patients of African ancestry.
“It remains imperative for clinicians to exercise clinical judgment and to be mindful of patient subsets that do not necessarily fit into recommendations designed for the majority or general populations,” Dr. Newman concluded in her editorial.
The USPSTF is funded by the Agency for Healthcare Research and Quality. Members of the task force receive travel reimbursement and honoraria for participating in USPSTF meetings.
