Search

Purpose An estimated 10% of breast and ovarian cancers result from hereditary causes. Current testing guidelines for germ line susceptibility genes in patients with breast carcinoma were developed to identify carriers of BRCA1/ 2 variants and have evolved in the panel-testing era. We evaluated the capability of the National Comprehensive Cancer Network (NCCN) guidelines to identify patients with breast cancer with pathogenic variants in expanded panel testing. Methods An institutional review board–approved multicenter prospective registry was initiated with 20 community and academic sites experienced in cancer genetic testing and counseling. Eligibility criteria included patients with a previously or newly diagnosed breast cancer who had not undergone either single- or multigene testing. Consecutive patients 18 to 90 years of age were consented and underwent an 80-gene panel test. Health Insurance Portability and Accountability Act–compliant electronic case report forms collected information on patient demographics, diagnoses, phenotypes, and test results. Results More than 1,000 patients were enrolled, and data records for 959 patients were analyzed; 49.95% met NCCN criteria, and 50.05% did not. Overall, 8.65% of patients had a pathogenic/likely pathogenic (P/LP) variant. Of patients who met NCCN guidelines with test results, 9.39% had a P/LP variant. Of patients who did not meet guidelines, 7.9% had a P/LP variant. The difference in positive results between these groups was not statistically significant (Fisher’s exact test P = .4241). Conclusion Our results indicate that nearly half of patients with breast cancer with a P/LP variant with clinically actionable and/or management guidelines in development are missed by current testing guidelines. We recommend that all patients with a diagnosis of breast cancer undergo expanded panel testing.

10504 Background: Pathogenic/likely pathogenic (P/LP) germline genetic variants are estimated to occur in 10-15% of all prostate cancer (PCa) patients. However, genetic testing for PCa patients is underutilized, partially due to complicated and restrictive testing guidelines developed at a time when the cost of testing was high. We conducted a study based in community urology clinics to determine the incidence of P/LP variants in PCa patients who met and did not meet the NCCN 2019 PCa germline genetic testing criteria. Methods: An IRB-approved, multicenter, prospective registry was initiated with 15 community and academic urologists nationwide. Eligibility criteria included patients with a PCa diagnosis unselected for personal or family history, stage or histology who had not been previously tested. Consecutive patients ages 18-90 were consented and underwent an 84-gene germline panel test. HIPAA-compliant electronic case report forms distributed to clinician collected information on patient diagnoses, NCCN testing criteria, and results-based recommendations. Results: To date, 640 enrolled patients have genetic testing results available. Overall, 69 (10.8%) patients had 72 P/LP variants detected, 15% of which were in BRCA1/2. Of the 532 patients for whom we have clinician-reported data, 293 (55%) met NCCN criteria and 239 (45%) did not. Median age was 70 (range 44-90). Overall, 11.1% (59/532) of patients with clinician-reported data had a P/LP variant. 36 (12.3%) of patients who met NCCN criteria and 23 (9.6%) of patients who did not meet criteria had a P/LP variant. The difference in P/LP rate between the two groups was not statistically significant (p=0.33). If only a conservative 12-gene PCa panel was considered, P/LP yield was 5.5% (29/532), with 8 (28%) of these patients missed by guidelines. Stratification by self-reported ethnicity was: 76% White/Caucasian (52 patients w/ P/LP), 18% Black/African American (2 patients w/ P/LP), and