Despite Few Genetic Services for Veterans With Cancer, Frequency of Possibly Pathogenic Germline Variants in Their Tumors Is Similar to that in the General Population
Greater access to and use of tumor profiling for patients treated through the US Department of Veterans Affairs (VA) Medical System may identify possibly pathogenic germline variants that need a referral for a genetics workup for evaluation and germline sequencing. To determine the proportion of veterans who would benefit from genetic counseling, researchers at the University of Michigan applied criteria regarding gene variants that may predispose patients to cancer to 208 veterans at the Veterans Administration Ann Arbor Healthcare System (VA AAHS) and to 20,014 veterans whose data was obtained from the National Precision Oncology Program (NPOP) database who had tumor profiling during the 5 years from 2015 to 2020 (JCO Oncol Pract. 2022; doi:10.1200/OP/21/00693).
The cancers in the VA AAHS cohort affected 20 different primary tumor sites, and 130 of the 208 patients in the cohort, or 63%, had advanced cancer at diagnosis. “[W]e sought to determine how many veterans have PPGVs [potentially pathogenic germline variants] on the basis of tumor-only sequencing to specifically characterize the scope of the unmet need for cancer genetics services within the VA,” wrote Anthony Scott, M.D., Ph.D., University of Michigan, Ann Arbor, MI, and colleagues.
In analyzing the VA AAHS cohort, the researchers reviewed annotated clinical reports of mutations identified by tumor-only profiling as well as the medical records of veterans with solid tumors. They then identified (PPGVs) by using the recommendations of the European Society for Medical Oncology and the American Board of Medical Genetics and Genomics, among other professional societies, as well as recommendations from published criteria or the consensus they reached from their experience at the VA AAHS. They then applied the same criteria to veterans whose data was obtained from the NPOP database.
Using these methods, the researchers found that 18 of the 208 patients in the VA AAHS cohort, or 8.5%, had mutations that were PPGVs. These 18 patients included many veterans who would not have received a referral for genetic counseling based on tumor type. Moreover, analysis of the national database revealed a similar percentage (6%) of PPGVs.
However, according to Dr Scott and colleagues, because of “a lack of confirmatory germline testing of these PPGVs [by] using a matched normal sample (blood or other nontumor sample), we cannot confirm what proportion of PPGVs are truly present in the germline.”
“Our results indicate a PPGV frequency (6%-9%) consistent with the prevalence of inherited cancer predisposition syndromes in the general population, underscoring the need for medical genetics as part of standard oncologic care for veterans,” Dr. Scott and colleagues wrote.
“These data point toward the need to expand genetics services for our veteran population. These services currently exist only at a handful of centers, and funding may be limited for their provision as well.”
“Challenges identified specific to the veteran population include paucity of genetics providers, either at a veteran’s VA facility or nearby non-VA facilities….We explore current and future care delivery models to optimize incorporation of medical genetics and genetic counseling to best serve veterans needing such services.”
