Background: According to recent research, breast cancer has become the most commonly diagnosed non-skin cancer type among the entire population. Meanwhile, Chinese herbal medicine (CHM) has become an important therapy to improve the survival rate and quality of life in metastatic cancer patients, as part of a wider trend toward more personalized medicine. However, there is a lack of research in terms of the association between stage IV breast cancer and CHM. Therefore, this study aimed to investigate the association between CHM and the survival rate in breast cancer patients at different cancer stages, with a particular focus on patients diagnosed with stage IV.
Methods: Patients with an initial diagnosis of breast cancer identified from the Taiwan Cancer Registry Database (TCRD) and China Medical University Hospital (CMUH) database were included in this study. Demographic characteristics including gender, age, and comorbidities were evaluated. Between-group differences for continuous and categorical variables were evaluated by the Student's t-test and Chi-square test, respectively. Patients diagnosed with breast cancer were recruited and divided into cohorts of CHM users and non-users with a 1:1 propensity score matching. The survival of breast cancer patients was assessed by the Cox proportional hazard model. The cumulative incidence of survival was assessed by Kaplan-Meier analysis.
Results: The adjuvant CHM treatment was associated with a higher survival rate in stage IV breast cancer patients (HR: 0.45, 95% CI: 0.2853-0.7044]. Additionally, the use of CHM had a positive impact on survival in stage IV breast cancer patients who had received surgery (P: .0273, HR: 0.3406, 95% CI: 0.1309-0.8865), chemotherapy (P: .0004, HR: 0.3893, 95% CI: 0.231-0.656), and hormone therapy (P: .0013, HR: 0.3491, 95% CI: 0.1836-0.6636). In terms of the specific CHM associated with survival, Zhi-Gan-Cao-Tang (ZGCT), Phellodendron chinense Schneid. (huang-bai), and Paeonia lactiflora Pall. (chi-shao) were the 3 most commonly prescribed herbal medicines correlated with a higher survival rate among stage IV breast cancer patients.
Conclusions: CHM associated with conventional management achieved significant survival benefits in patients with stage IV breast cancer. Additional randomized controlled trials for prospective study are recommended for further validation.
Keywords: Chinese herbal medicine; Taiwan Cancer Registry Database; Zhi-Gan-Cao-Tang; breast cancer; retrospective cohort study.