The efficacy and safety of Xihuang Pill/capsule in adjuvant treatment of breast cancer: A systematic review and meta-analysis of 26 randomized controlled trials

Xihuang Pill is a traditional Chinese medicine prescription for the treatment of breast cancer. There are many randomized controlled trials (RCTs) of Xihuang Pill in the treatment of breast cancer that have been published. Hence, a comprehensive systematic review and meta-analysis is needed.To evaluate the safety of Xihuang pill/capsule and its effect on the improvement of tumor progression, quality of life, immunity and prognosis in adjuvant treatment of breast cancer.Chinese and English databases such as Sinomed, PubMed, Embase were searched to collect the RCTs of Xihuang pill/capsule in adjuvant treatment of breast cancer. Then the researchers extracted data from the RCTs that met the inclusion criteria, and used Cochrane standard risk bias to assess the quality of the data, and used Rev Man 5.3 statistical software for statistical analysis.A total of 26 RCTs with 2272 participants were included. The primary outcomes showed that Xihuang pill combined with chemotherapy and with endocrine therapy may suppress of tumor progression {Chemotherapy: risk ratio (RR) = 0.59, 95%Confidence interval (CI) [0.48,0.73], P < 0.00001; Endocrine therapy: RR = 0.56, 95%CI [0.33,0.96], P = 0.04}. Xihuang pill combined with chemotherapy, with endocrine therapy and with radiotherapy may improve the quality of life (chemotherapy: RR = 1.73, 95%CI[1.11, 2.70], P = 0.02; Endocrine therapy: RR = 1.18, 95%CI [1.01,1.38], P = 0.03; radiotherapy:RR = 1.51, 95%CI [1.01,2.27], P = 0.05). Xihuang pill combined with TCM + chemotherapy may decrease the inefficiency rate for clinical symptom improvement (RR = 0.50, 95%CI [0.28, 0.88], P = 0.02). Xihuang pill combined with chemotherapy may increase the Karnofsky Performance Scale (KPS) {Weighted Mean Difference (WMD) = 15.40, 95%CI [8.18, 22.62], P < 0.0001}. For adverse events, Xihuang pill combined with chemotherapy may alleviate adverse digestive events and leukopenia; Xihuang pill combined with endocrine therapy will not increase adverse events; Xihuang pill combined with non-antitumor therapy may reduce the incidence of leukopenia and red blood cell or hemoglobin reduction.The addition of Xihuang pill/capsule to breast cancer in conventional anti-tumor therapy may inhibit tumor progression, improve patient quality of life, reduce toxic reactions, regulate immunity, and reduce tumor markers. However, due to the overall low quality of RCTs, the research results need more high-quality RCTs to further test the conclusions.