Landscape of potential germline pathogenic variants in select cancer susceptibility genes in patients with adult-type ovarian granulosa cell tumors

OBJECTIVE

The objective of this study was to assess the frequency of potential germline pathogenic variants that may contribute to risk of development of adult granulosa cell tumors (AGCT) given the paucity of germline testing guidelines for these patients.

METHODS

This was a retrospective cross-sectional study analyzing comprehensive genomic profiling (CGP) results of AGCT with the FOXL2 p.C134W mutation submitted to Foundation Medicine between 2012 and 2022. Cases with a potential germline pathogenic variant were identified by filtering single nucleotide variants and short indels by variant allele frequency (VAF) and presence in ClinVar for select cancer susceptibility genes. Odds ratios for AGCT risk were calculated compared to a healthy population.

RESULTS

Prior to analysis, 595 patients were screened and 516 with a somatic FOXL2 p.C134W mutation were included. Potential germline pathogenic variants in a DNA repair-related gene (ATM, BRCA1, BRCA2, CHEK2, PALB2, PMS2, RAD51C, or RAD51D) were found in 6.6% of FOXL2-mutated AGCT. Potential germline pathogenic CHEK2 variants were found in 3.5% (18/516) of AGCT patients, a rate that was 2.8-fold higher than Genome Aggregation Database non-cancer subjects (95% CI 1.8-4.6, p < 0.001). The founder variants p.I157T (38.9%, 7/18) and p.T367fs*15 (c.1100delC; 27.8%, 5/18) were most commonly observed. CHEK2 VAF indicated frequent loss of the wildtype copy of the gene.

CONCLUSIONS

These results support ongoing utilization of genomic tumor profiling and confirmatory germline testing for potential germline pathogenic variants. Further prospective investigation into the biology of germline variants in this population is warranted.

Integrating Medical Genetics Into Precision Oncology Practice in the Veterans Health Administration: The Time Is Now

PURPOSE

Increased access and utilization of tumor profiling of cancers in our veteran population uncovered a modest number of potentially pathogenic germline variants (PPGVs) that require genetics referral for follow-up evaluation and germline sequencing. 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 sought to investigate the number of veterans who would benefit from having such resources at both local and national levels.

METHODS

Annotated clinical reports of mutations identified by tumor-only profiling and medical records of veterans with solid tumors at the Veterans Administration Ann Arbor Healthcare System (VA AAHS) between 2015 and 2020 were reviewed. PPGVs were identified according to society recommendations (such as ESMO and American Board of Medical Genetics and Genomics), expert review, and/or previously published criteria. After the analysis of our local VA population, these same criteria were then applied to veterans in the National Precision Oncology Program (NPOP).

RESULTS

Two hundred eight veterans underwent tumor profiling at the VA AAHS over the defined time period. This included 20 different primary tumor sites with over half (n = 130) being advanced cancer at diagnosis. Of these, 18 veterans (8.5%) had mutations suggestive of a PPGV. Applying these criteria to the larger NPOP database (n = 20,014), a similar percentage (6%) of PPGVs were identified.

CONCLUSION

These results indicate a PPGV frequency (6%-9% of veterans) 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. We explore current and future care delivery models to optimize incorporation of medical genetics and genetic counseling to best serve veterans needing such services.