Characteristics of early short-term traditional Chinese medicine in breast cancer patients: A population-based cohort study

Background: Traditional Chinese medicine (TCM) is frequently utilized as a complementary therapy for breast cancer patients. TCM primarily involves the use of Chinese herbal products (CHPs), which consist of single or multiherb formulas with diverse therapeutic effects documented in medical classics. The study aims to investigate the association between medication possession ratios to CHPs within 2-year post breast cancer diagnosis and 5-year survival, to explore the potential beneficial class effect of TCM. Methods: This retrospective population-based cohort study included newly diagnosed breast cancer patients between 2003 and 2006, identified from the National Health Insurance Research Database of Taiwan. Logistic regression and Cox proportional hazards analysis were utilized to assess the likelihood of medication possession ratios (MPRs) for CHPs and to examine the association of variables with 5-year survival. Results: A total of 3472 patients with breast cancer were included. Patients who had MPR of 1% to 9% and 10% to 19% for CHPs within 2 years after breast cancer diagnosis exhibited better 5-year survival rates compared with those who did not use CHPs (adjusted hazard ratio [aHR] 0.69, 95% confidence interval [CI] 0.55-0.86, p = 0.001; aHR 0.50, 95% CI 0.28-0.88, p = 0.016). Furthermore, the use of TCM formulations specifically targeting insomnia, such as Tian-wang-bu-xin-dan and Suan-zao-ren-tang, demonstrated a significantly positive association with survival (aHR 0.71, 95% CI 0.52-0.98, p = 0.035) among patients who were short-term users of CHPs (MPR of 1% to 19%). Conclusion: Short-term use of TCM (ie, MPR to CHPs 1~19%) within 2-year post breast cancer diagnosis present positive association with survival outcome. Tian-wang-bu-xin-dan and Suan-zao-ren-tang may have benefits to 5-year survival, but their causality still need further investigation.