ASPO Abstracts
Beyond tamoxifen use for breast cancer treatment: factors unique to secondary endometrial cancer diagnosis
Category: Early Detection & Risk Prediction, Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2018
Abstract Body:
Purpose: Tamoxifen treatment for breast cancer is known to increase risk of endometrial cancer; however, few studies have identified other factors associated with endometrial cancer following breast cancer treatment with tamoxifen. The objective of the study is to compare the sociodemographic and clinical factors of patients diagnosed with endometrial cancer after breast cancer with those of patients with primary endometrial cancer and with primary breast cancer only. Methods: We conducted a case-comparison study using the population-based Surveillance, Epidemiology, and End Results (SEER) dataset. Among women, ages 20-89, between the years 1978 and 2013, we defined cases as patients diagnosed with endometrial cancer at least 6 months after a breast cancer diagnosis. We created two comparison groups : 1) women diagnosed with primary breast cancer or primary endometrial cancer and did not have a secondary cancer diagnosis during the defined period , and 2) women diagnosed with cancer at a site other than the breast or reproductive tract. Race/ethnicity, stage at diagnosis, menopausal status (pre < 50 years at diagnosis; post 50 years), and tumor grade were used as covariates. Results: Women with secondary endometrial were more likely to be older at breast cancer diagnosis compared to women with breast cancer only (OR: 1.04), 95% CI: 1.024-1.05), and were also more likely to have higher grade, earlier stage breast cancer compared to women diagnosed with breast cancer only. Compared to women diagnosed with primary endometrial cancer only , women with secondary endometrial cancer were older at endometrial cancer diagnosis (OR: 1.202; 95% CI: 1.18-1.23), and had higher endometrial tumor grade. Conclusion: Identifying the differences between these cancer patient groups may reveal insights for identifying risk factors for endometrial cancer among women being treated for breast cancer. Ultimately, recognizing such risk factors can help guide breast cancer treatment decisions and avoid subsequent endometrial cancer.
Keywords: Cancer Prevention, Breast and Endometrial cancer, SEER