ESR1 A908G mutation-positive breast cancer was significantly associated with a first-degree family history of breast cancer (odds ratio [OR] = 2.69, 95% confidence interval [CI] = 1.15 to 6.28), whereas mutation-negative breast cancer was not.
This population-based study, the largest so far to screen for the ER-alpha A908G mutation in breast cancer, confirms the presence of the mutant in invasive breast tumors.