Risk factors for the development of uterine cancer in breast cancer survivors: an army of women study.

Background: Our study compares breast cancer survivors without a secondary diagnosis of uterine cancer (BC) to breast cancer survivors with a diagnosis of uterine cancer (BUC) to determine clinical characteristics that increase the odds of developing uterine cancer.
Methods: A total of 7,228 breast cancer survivors were surveyed. A case-control study was performed with 173 BUC patients matched by age and race in a 1:5 ratio to 865 BC patients. Multivariable logistic regression examined which factors influence the odds of developing uterine cancer.
Results: A total of 5,980 (82.3 %) women did not have a previous hysterectomy at the time of breast cancer diagnosis, of which 173 (2.9 %) subsequently developed uterine cancer. There was no significant difference in body mass index (BMI) (34.4 vs. 34.1, p = 0.388) or age (52.3 vs. 52.3 years, p = 0.999) between the two groups. Increased odds for developing uterine cancer were found in patients with a personal history of hypertension [odds ratio (OR) = 1.62, 95 % confidence interval (CI) 1.45-2.70, p < 0.001], gallbladder disease (OR = 1.30, 95 % CI 1.14-1.55, p = 0.005), and thyroid disease (OR = 1.55, 95 % CI 1.37-1.69, p < 0.001). More than 80 % of women in both groups expressed a desire for a blood test to estimate the risk of uterine cancer (80.4 % BUC vs. 91.2 % BC, p < 0.001).
Conclusions: Hypertension, gallbladder disease, and thyroid disease in breast cancer survivors increase the odds of developing uterine cancer. Breast cancer survivors also express significant interest in potential serum tests to assess the risk of developing uterine cancer.