The Prescription Pattern of Chinese Herbal Products Containing Ginseng among Tamoxifen-Treated Female Breast Cancer Survivors in Taiwan: A Population-Based Study

Background. The purpose of our study is to analyze the association between prescribed Chinese herbal products (CHPs) containing Ginseng and the risk of endometrial cancer among tamoxifen (TMX) users and to identify any possible interactive effects between Ginseng and TMX with respect to preventing the development of subsequent endometrial cancer in an estrogen-dependent breast cancer population in Taiwan. Methods. All patients newly diagnosed with invasive breast cancer receiving tamoxifen treatment from January 1, 1998, to December 31, 2008, were selected from the National Health Insurance Research Database. The usage, frequency of service, and CHP-Ginseng prescribed across the 30,556 TMX-treated breast cancer (BC) survivors were evaluated. Logistic regression was employed to estimate the odds ratios (ORs) for the utilization of CHP-Ginseng. Cox's proportional hazard regression was performed to calculate the hazard ratios (HRs) for endometrial cancer associated with Ginseng use among the TMX-treated BC cohort. Results. The HR for the development of endometrial cancer among breast cancer survivors who had ever taken Ginseng after TXM treatment was significantly decreased compared to those who never used CHP. Conclusion. A significant inhibitory relationship between Ginseng consumption and subsequent endometrial cancer less than 2 years after TMX treatment was detected among BC survivors.