Adherence to National Comprehensive Cancer Network Guidelines for testing among high risk breast Cancer patients: a retrospective chart review study.

Background: Testing for variants can impact treatment decisions for breast cancer patients and affect surveillance and prevention strategies for both patients and their relatives. National Comprehensive Cancer Network (NCCN) guidelines recommend testing for patients at heightened risk of pathogenic variant. We examined the testing rate among high risk breast cancer patients treated in community oncology practices.

Methods: We conducted a retrospective medical chart review among community-based US oncologists using a physician panel approach. High risk breast cancer patients with a known family history of cancer and diagnosis with breast cancer at age ≥ 18 years between January 2013-October 2017 were included. We assessed the proportions of patients tested for variants in accordance with NCCN guidelines.

Results: Charts from 63 physicians, averaging 16 years of practice, were included; 97% were medical oncologists and 66.7% had a genetic counselor in their practice. We analyzed data for 410 randomly-selected patients with mean age of 52 years; 95% were female, 74% were White, and 19% had Ashkenazi Jewish ancestry. Among all patients, 94% were tested for variants. The testing rate ranged from 78 to 100% in various high risk groups; lower rates were observed among Black patients (91%), men (92%), and patients meeting NCCN criteria based on family history of male breast cancer (78%) and prostate cancer (87%). We observed a higher testing rate in patients treated by physicians with a genetic counselor in their practice (95% versus 91%).

Conclusions: Adherence to NCCN testing guidelines is high in this group of predominantly medical oncologists with extensive experience, with a high proportion having a genetic counselor in practice. Testing rates can be improved in patients with risk factors related to male relatives. High level of compliance to guidelines in a community setting is possible with a delivery model for genetic counseling and testing.