Combination of chemotherapy and immunotherapy for colon cancer in China: A meta-analysis

AIM:To investigate whether autologous dendritic cell(DC)-cytokine-induced killer(CIK)cell therapy is able to improve the therapeutic efficacy of chemotherapy in colon cancer.METHODS:We conducted a systematic review of published papers from the sources of MEDLINE,the Cochrane Central Register of Controlled Trials,EMBASE,the Wanfang Database,the China Science and Technology Periodical Database and China Journal Net.Published data were extracted independently by two authors using predefined database templates.The quality of the data from individual papers was also assessed.The effects of chemotherapy were compared with those of chemotherapy in combination with DC-CIK immunotherapy.The pooled analysis was performed using the data from random or fixed-effect models.RESULTS:Seven trials matched our inclusion criteria(n=533).The overall analysis showed significant survival benefit[one-year overall survival(OS),P<0.0001;twoyear OS,P=0.009;three-year OS,P=0.002]in favor of DC-CIK immunotherapy combined with chemotherapy.Disease-free survival(DFS)rate was improved after the combination of DC-CIK immunotherapy and chemotherapy(one-year DFS,P<0.0001;two-year DFS,P=0.002;three-year DFS,P=0.02).An improved overall response rate(P=0.009)was also observed in patients who received DC-CIK therapy.Furthermore,the analysis of T-lymphocyte subsets in peripheral blood indicated that the number of CD4+T cells significantly increased in the DC-CIK plus chemotherapy group(P<0.05).CONCLUSION:The combination of DC-CIK immunotherapy and chemotherapy was superior in prolonging the survival time and enhancing immunological responses.