Adherence to NCCN Guidelines for Genetic Testing in Breast Cancer Patients: Who Are We Missing?

Genetic predisposition accounts for 5-10% of all breast cancers (BC) diagnosed. NCCN guidelines help providers identify appropriate candidates for counseling and testing. Concerns about underutilization of genetic testing have spurred interest in broader peri-diagnostic testing. We evaluated surgeon adherence to NCCN guidelines and studied patterns of testing in newly diagnosed BC patients.

A total of 397 patients were identified with newly diagnosed BC treated at our institution between 2016 and 2017 with no prior genetic testing. Eligibility for genetic testing based on NCCN criteria, referral, and patient compliance were recorded.

In total, 212 of 397 (53%) met NCCN testing criteria. Fifty-nine of 212 (28%) patients went untested despite meeting one or more criteria. Fourteen of 59 (24%) of these were referred but did not comply. Most common criteria for meeting eligibility for testing both in the overall cohort and among missed patients were family history-based. Age > 45 years old and non-Ashkenazi Jewish descent were predictive of missed referral (p < 0.01). We identified pathogenic mutations in 16 of 153 (10%) patients who did undergo testing (11 (7%) BRCA1 or 2 and 5 (3%) with other predisposition gene mutations) or 16 of 397 (4%) among the overall group.

Our data highlight the underutilization of genetic testing. Even in the setting of a full-service breast center with readily available genetic counseling, there is a substantial miss rate for identifying eligible patients, related to assessment of family history, patient age, and ethnicity, as well as patient compliance. Broader peri-diagnostic testing should be considered, and higher compliance rates with patients referred should be sought.