The Effect of Family History of Breast Cancer and Breast Biopsies on Breast Cancer Risk and Outcomes in the California Teachers Study Cohort

Breast cancer is the most frequently diagnosed invasive cancer in women in the United States. Factors that influence the relationship between family history of breast cancer, history of non-diagnostic breast biopsy, and breast cancer risk are not fully understood. This study explored the relationships between family history of breast cancer, biopsy history, and breast cancer outcome. The associations between tumor characteristics such as stage of diagnosis, tumor size, histology, receptor status, survival, and family and biopsy history were examined.;The dataset used for this study was from the California Teachers Study (CTS) cohort. The CTS is a long-term, follow-up (prospective cohort) study of 133,479 female teachers and school administrators. In 1995 and 1996, participants completed an extensive questionnaire that focused on lifestyle, medical history, and women's health. Follow up data collection is done annually. The outcomes data used for this study is as of 2010.;Our results show a positive association between family history of breast cancer and history of non-diagnostic breast biopsy, however, having a history of breast biopsy was not associated with early stage at diagnosis, tumor grade, tumor size, or receptor status of breast cancer. Our results also indicate that women with positive family history of breast cancer, post-menopausal women, pre- and post-menopausal African American women, women who have regular mammograms, and women on hormone therapy are more likely to report a history of breast biopsy.;We conclude that history of non-diagnostic breast biopsy is not associated with breast cancer risk prediction or disease outcome.