199 Background: Data on germline DNA repair defects and VUS rates are sparse in African American (AA) men with metastatic prostate cancer (PCa). Methods: Germline testing data from two centers with a significant percentage of metastatic AA PCa patients were combined and compared to Caucasian American (CA) with metastatic PCa. Fourteen canonical DNA repair genes (ATM, BARD1, BRCA1, BRCA2, BRIP1, CHEK2, MLH1, MSH2, MSH6, NBN, PALB2, PMS2, RAD51C, RAD51D) were assessed in all tested patients (pts) using a pathogenic/likely pathogenic (P/LP) classification. Variants of unknown significance (VUS) were assessed in an Invitae-derived dataset with consistent VUS reporting. Results: A total of 105 AA men with metastatic disease were evaluated and 7/105 of these men (6.67%) had P/LP alteration. Among the AA pt alterations, there were 4 pts with BRCA2, 2 pts with BRCA1, and 1 pt with PALB2. A total of 39/417 (9.3%) of CA metastatic patients had P/LP alterations in the canonical 14 genes. No differences were detected in the AA vs CA metastatic comparison (p=0.39). A total of 1/105 (0.95%) AA pts and 23/418 (5.5%) CA had non-BRCA P/LP mutations. The number of non-BRCA P/LP mutations were lower in the AA as compared to the CA men (p=0.045). When evaluating VUS calls in the metastatic AAs using Invitae multi-gene panels, 28/92 (30.43%) pts had a VUS in the canonical 14 genes as compared to 67/366 (18.31%) of the CA men. AAs were more likely than CA to have a VUS (p=0.010). These data indicate that metastatic AA pts and CA are not significantly distinct in the P/LP alterations in 14 canonical DNA repair genes but that there were lower percentages of P/LP in the AA non-BRCA gene subset. Further, when assessing these genes, it is clear that a VUS is more likely to be called in the AA men. Conclusions: Among men with metastatic PCa, AAs have similar rates of inherited P/LP alterations in 14 well accepted DNA repair genes as compared to CA men, however the non-BRCA gene P/LP alterations were less frequent among the AAs. Variants classified as a VUS were clearly higher in these AA pts as compared to the CA pts.

5568 Background: The relevance of germline mutations in metastatic prostate cancer is well established; however, comparison of germline genetics in African American (AA) versus Caucasian (CA) men with metastatic prostate cancer (PCa) is limited. Methods: Germline data from self-identified AA and CA metastatic PCa patients (pts) were collected from 5 academic cancer centers. Various commercial cancer-specific germline testing panels were used to evaluate 12-86 genes. Pathogenic (P) or likely pathogenic (LP) mutations, and variants of unknown significance (VUS), were reported according to ACMG guidelines. Self-reported family history (FH) was annotated for 99% of pts. Statistical analyses included Chi-squared and Fischer’s exact tests. Results: A total of 821 metastatic PCa pts were assessed: 152 AAs and 669 CAs. For P/LP alterations, AAs had a frequency of 11.2% (17/152) as compared to a frequency of 14.6% (98/669) in CAs (p = 0.302). AA pts were more likely to have a VUS than CA pts, 61% vs 43% respectively (OR = 2.09, 95%CI [1.45, 2.99], p < 0.001). BRCA mutations were similar between races, but AA were more likely to have a BRCA1 P/LP alteration (OR = 6.00, 95% CI [1.33, 27.09], p = 0.025). AA pts were less likely to have a P/LP alteration in a non-BRCA gene (OR = 0.34, 95% CI [0.15, 0.80], p = 0.013). Among DNA repair genes, there were no significant difference between AA and CA pts (p = 0.574); however, there was a trend toward AA pts having fewer P/LP alteration in a non-BRCA DNA repair genes (OR = 0.26, 95% CI [0.06, 1.08], p = 0.071). In pts with >1 first degree relative (FDR) with ovarian cancer, P/LP germline alterations were more likely in CAs (OR = 2.33, 95% CI [1.05, 5.17], p = 0.043); but there were no significant differences in AAs (p = 0.098). Those with >2 FDRs with PCa were more likely to have a P/LP change in CAs (OR = 2.32, 95% CI [1.04, 5.15], p = 0.043), but there were no difference in AAs (p = 0.700). In pts with ≥2 FDRs with breast cancer, P/LP germline alterations were more likely in both AAs (OR = 9.36, 95% CI [1.72, 50.84], p = 0.019) and CAs (OR = 3.92, 95% CI [1.79, 8.59], p = 0.001). Conclusions: We did not observe a difference in the overall frequency of germline P/LP alterations between AA and CA men with metastatic PCa but VUSs were more common in AA men. These AA men have an overall frequency of BRCA mutations similar to CA men; however, BRCA1 mutations were more prevalent in these AAs. Non-BRCA P/LP mutations are significantly less frequent in AA pts. A positive family history of >2 FDRs with breast cancer was associated with P/LP alterations in both AA and CA pts.

6508 Background: Physicians in the community have a broad range of experience using genomics data to inform treatment decisions. They typically have a heavier patient load than found in academic centers and treat a variety of tumor types. Genomic data has been reportedly used less than anticipated, even when results were actionable. Monthly didactic molecular tumor boards have been implemented in a number of cancer centers to try to fill gaps in knowledge. Methods: A weekly virtual consultative molecular tumor board (MTB) was implemented (Mar 2016) at an academic hybrid, multi-site community-based cancer institute to provide rapid molecularly-driven treatment guidance to physicians, augment genomics education, provide supporting documents for off-label use and clinical trials. A baseline survey was performed prior to first MTB. MTB assessments were summarized and provided to treating physician. Data was abstracted from the electronic medical records and clinical trials management system. Descriptive statistics were utilized to summarize utilization of MTB and treatment recommendations. Results: Genomics testing with a large panel (~600 genes) was requested for 809 patients (Jun 2015-Feb 2017). The MTB received 81 requests for review from 32 physicians from 14 locations. Most commonly reviewed disease sites were lung, ovary, pancreatic, colon, breast and head and neck cancers; 37% of reviews requested were for rare tumors. Median time to review request was 15 days from receipt of results. MTB recommendations were followed in 70% of cases, 16% continued current/other therapy, 11% declined rapidly (hospice/died), and 3% of patients decided against recommendations. Forty-four (44) percent were screened for recommended clinical trials; 26% went on study. Conclusions: Implementation of a weekly virtual consultative MTB facilitates molecularly-driven treatment decisions in community setting, especially in rare tumor types and enhances clinical trial accruals.

Genetic testing is important for comprehensive cancer care. Commercial analysis of the BRCA1/2 genes has been available since 1996, and testing for hereditary breast and ovarian cancer syndrome is well established. The National Comprehensive Cancer Network (NCCN) guidelines identify individuals for whom BRCA1/2 analysis is appropriate and define management recommendations for mutation carriers. Despite recommendations, not all who meet NCCN criteria undergo genetic testing. We assess the frequency that individuals meeting NCCN criteria decline BRCA1/2 analysis, as well as factors that affect the decision-making process. A retrospective chart review was performed from September 2013 through August 2014 of individuals who received genetic counseling at the Levine Cancer Institute. A total of 1082 individuals identified through the retrospective chart review met NCCN criteria for BRCA1/2 analysis. Of these, 267 (24.7%) did not pursue genetic testing. Of the Nontested cohort, 59 (22.1%) were disinterested in testing and 108 (40.4%) were advised to gather additional genetic or medical information about their relatives before testing. The remaining 100 (37.5%) individuals were insured and desired to undergo genetic testing but were prohibited by the expense. Eighty five of these 100 patients were responsible for the total cost of the test, whereas the remaining 15 faced a prohibitive copay expense. Financial concerns are a major deterrent to the pursuit of BRCA1/2 analysis among those who meet NCNN criteria, especially in patients diagnosed with breast or ovarian cancer. These findings highlight the need to address financial concerns for genetic testing in this high-risk population.