Complementary Chinese herbal medicine therapy improves survival of patients with gastric cancer in Taiwan: A nationwide retrospective matched-cohort study

Ethnopharmacological relevance: Many patients with gastric cancer seek traditional medicine consultations in Asian countries. This study aimed to investigate the prescription of Chinese herbal medicine (CHM) and its benefits for the patients with gastric cancer in Taiwan. Methods: From the Registry for Catastrophic Illness Patients Database, we included all patients with gastric cancer whose age at diagnosis was >= 18 from 1997 to 2010 in Taiwan. We used 1:1 frequency matching by age, sex, Charlson comorbidity score, treatment and index year to compare the CHM users and non-CHM users. We used the Cox regression model to compare the hazard ratios (HR) for the risk of mortality and the Kaplan-Meier curve for the survival time. Results: There was a total of 1333 patients in the CHM-cohort and 44786 patients in the non-CHM cohort. After matching, we compared 962 newly diagnosed CHM users and 962 non-CHM users. Adjusted HRs (aHR) were higher among patients of above 60-year-old group, with a Charlson Comorbidity Index score >= 2 before the index date, and those who need surgery combined with chemotherapy or radiotherapy. CHM users had a lower HR of mortality risk (adjusted HR: 0.55, 95% CI: 0.48-0.62). Compared to the non-CHM users, the aHR among CHM-users is 0.37 (95% CI:0.2-0.67) for those who used CHM more than 180 days annually. The Kaplan-Meier curve revealed that the survival probability was higher for complementary CHM-users. Bai-Hua-She-SheCao (Herba Hedyotidis Diffusae) was the most commonly used single herb and Xiang-Sha-Liu-Jun-Zi-Tang was the most commonly used herbal formula among CHM prescriptions. Conclusions: Complementary CHM improves the overall survival among patients with gastric cancer in Taiwan. Further ethnopharmacological investigations and clinical trials are required to validate the efficacy and safety.