The efficacy of Chinese herbal medicine as an adjunctive therapy for colorectal cancer: A systematic review and meta-analysis

Although Chinese herbal medicine (CHM) has been widely used as an adjunctive therapy for colorectal cancer in Asia, its efficacy is not well defined. The purpose of this systematic review is to assess the efficacy of CHM as an adjunctive therapy to chemotherapy for the patients with colorectal cancer. Randomized controlled trials with CHM to treat colorectal cancer were extensively searched in seven databases. Two researchers independently assessed the quality and validity of included trials and extracted outcome data for synthesis. 20 trials were included for analysis. Compared to using chemotherapy alone, CHM combined with chemotherapy significantly increased 1- and 3-year survival rate [odds ratio (OR) 2.41, 95% confidence interval (CI) 1.32-4.41; OR 2.40, 95% CI 1.49-3.87]. The combined therapy significantly slowed colorectal cancer progression (OR 0.50, 95% CI 0.32-0.77) and improved quality of life (OR 3.43, 95% CI 2.35-5.02). It had positive effects in immunoregulation. CHM as an adjunctive therapy also had significant advantages in reducing the adverse effects of chemotherapy. This systematic review suggests that CHM as an adjunctive therapy with chemotherapy versus chemotherapy alone has significant efficacy in terms of prolonging survival, enhancement of tumor response, improvement of quality of life, immunoregulation, and alleviation of acute adverse effects. However, a firm conclusion could not be reached because of the poor quality of the included trials. Further trials with higher quality are required and the efficacy in other forms of advantages remains to be further determined.