Mainstreamed genetic testing of patients with breast cancer: Experience from a single surgeon’s practice in a large U.S. academic center.

Abstract

10577 Background: Germline genetic testing for cancer susceptibility has proven to be a powerful tool in cancer risk assessment, screening, and prevention but a huge gap exists between the number of germline genetic testing candidates and the number of patients actually tested. This study aimed to evaluate the impact of mainstreamed genetic testing (MGT) model into a single academic breast surgeon’s practice on genetic test completion. Methods: Before September 2019 (pre-MGT phase), a breast surgery practice at Massachusetts General Hospital followed a traditional model of pre-test consultation with a genetic professional. After September 2019 (post-MGT phase), the same practice offered eligible patients with immediate testing in the same visit. We evaluated the appointment completion in the pre-MGT phase and compared the test uptake and test results between the two phases. Results: We identified 204 patients in the pre-MGT phase and 202 patients in the post-MGT phase. In the pre-MGT phase, the median waiting time for genetic counseling was seven days for patients with a newly diagnosed cancer, 211 days for patients with a remote personal history of cancer, and 224 days for non-cancer patients who had a family history. A total of 105 (51.5%) patients completed a genetic counseling appointment (Table). In the post-MGT phase, a significantly higher proportion of patients (88.1%, p < 0.001) consented to genetic testing, while the proportion of patients who tested positive was lower (pathogenic variant: 11.9% vs. 20.0%; variant of uncertain significance: 19.9% vs. 28.0%; p = 0.047). Conclusions: Implementing MGT can reduce the number of clinical visits, significantly shorten patients’ wait time to test initiation, and increase the completion of genetic testing. [Table: see text]