Uterine serous carcinoma and germline genetic testing: patterns of referral, completion and pathogenic variant detection.

BACKGROUND: Current guidelines recommend consideration of germline genetic testing for patients with uterine serous carcinoma (USC) but real-world data are limited on completion rates of testing and pathogenic variant (PV) identification. This study aimed to evaluate the rate of genetic testing referral and completion in a cohort of patients with USC, determine the prevalence of clinically meaningful PVs found on testing and explore factors associated with genetics referral and testing completion. METHODS: We retrospectively examined the medical records of all individuals diagnosed with USC between 2019 and 2024 seen at a single academic cancer centre. Outcomes of interest included referral for germline genetic testing, completion of testing and testing results. RESULTS: . Only a personal history of cancer other than USC was independently associated with the discovery of a PV on germline genetic testing. In those without a prior personal history of cancer, the PV prevalence was 5.6%. CONCLUSIONS: Given the high prevalence of PVs in this population, germline genetic testing for all patients diagnosed with USC can provide clinically meaningful benefit but is currently underused in practice.