Association of Community Cancer Centers: Institution-Directed Quality Improvement of Genetic Counseling and Testing for Community Oncology Patients with Breast Cancer

Abstract

Hereditary breast cancer accounts for 10 percent of all breast cancers currently diagnosed in the United States. 1 About 30 percent of the known inherited breast cancers are associated with pathogenic (or likely pathogenic variants) in BRCA1/2, 2,3 the most understood germline mutations. These cancers occur earlier in life and more often in patients with cancer susceptibility genes. The mean age of patients with germline BRCA1/2 pathogenic variants who develop breast cancer is considerably lower, compared to the mean age of patients with sporadic breast cancer (42 years vs. 64 years, respectively), which clearly factors into decision making. There is a higher prevalence of triple-negative breast cancer (estrogen receptor [ER]−, progesterone receptor [PR]−, human epidermal growth factor receptor 2 [HER2]-) among those with a pathogenic BRCA1 variant, while individuals with a pathogenic variant in BRCA2 more commonly develop ER+ breast cancer and lower grade tumors. 4 Additionally, patients with a pathogenic variant in BRCA1/2 have a higher risk of developing a second primary breast cancer and other cancers, including pancreatic cancer, ovarian cancer in women, and prostate cancer in men. 3,4