Is survival among women diagnosed with breast cancer influenced by family history of breast cancer?

In this study, we examine the association between having a family history of breast cancer and survival after diagnosis with breast cancer. Data for this study were from the Utah Population Database, a linked database consisting of genealogy data of Mormon pioneer families, Utah Cancer Registry data, and Vital Statistics data. We observed that women who had a mother with breast cancer were more likely to die of any cause than women without a mother with breast cancer [hazard rate ratio (HRR) = 1.36, 95% confidence limits (CL) = 1.04, 1.79], as were women with over 30 female relatives with breast cancer (HRR = 1.69, 95% CL = 1.16, 2.45). Similar findings were observed for women dying of breast cancer. Other indicators of family history were not associated with survival except within specific age groups. Women diagnosed with breast cancer at age 50 or before had poorer survival if they had a family history of breast cancer. Relative risk estimates were 1.54 (95% CL = 0.98, 2.41) for first degree relative, 1.55 (95% CL = 0.87, 2.78) for mother, and 2.65 (95% CL = 1.23, 5.74) for more than 30 female relatives with breast cancer.