Use of germline testing in patients with prostate, pancreatic, or ovarian cancer in Washington (WA) state.

6572 Background: Germline genetic mutations are seen in approximately 10-15% of patients with prostate, pancreatic, and ovarian cancer. While universal germline testing is recommended for patients with these cancers to inform both familial risk and therapeutic approach, underutilization of germline testing has been reported. We investigated the rates of and factors associated with germline testing in a population-based sample of patients with prostate, pancreatic, and ovarian cancer in WA state. Methods: We linked Washington state cancer registry records from 2017-2019 with claims records for two large commercial insurers, Medicare, and Medicaid. Patients with prostate (metastatic, regional node-positive, or high-risk localized), pancreatic, and ovarian (including fallopian tube and peritoneum) cancer who were diagnosed in 2017-2019 were identified. Using claims from this database, we identified patients who received germline testing in the first two years of diagnosis. We excluded those who were not continuously enrolled in a health plan during the testing period of interest or died within 3 months of diagnosis. We used a multivariate logistic regression model to investigate factors associated with germline testing. Results: Among 2,077 patients, 429 (20.7%) received germline testing. Testing rates were 6.3% (53 of 842 patients) in prostate cancer, 15.4% (118 of 765 patients) in pancreas cancer, and to 54.9% (258 of 470 patients) in ovarian cancer; median time to testing for prostate, pancreas, and ovarian cancer was 162, 133, and 64 days respectively. Testing rates were higher in later years, in patients with more advanced stage cancers and lower in Asian patients and patients with more comorbid conditions. Conclusions: Despite guideline recommendations, germline testing rates are low among cancer patients in WA state, with the lowest rates in prostate cancer patients and in Asian and higher comorbidity populations. Underutilization of germline testing may not only adversely affect treatment, but also represents a missed opportunity for testing of high-risk families. Further studies should identify and address barriers to germline testing in high-risk populations. [Table: see text]