ObjectiveTo systematically review the efficacy and safety of capecitabine combined with irinotecan (CAPIRI) versus capecitabine combined with oxaliplatin (CAPOX) for patients with advanced/metastatic colorectal cancer.MethodsPubMed, EMbase, The Cochrane Library, VIP, WanFang Data and CNKI databases were electronically searched to collect randomized controlled trials (RCTs) on CAPIRI versus CAPOX for patients with advanced/metastatic colorectal cancer from inception to August 2018. Two reviewers independently screened literature, extracted data, and assessed the risk of bias of included studies. Then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 12 RCTs involving 1 049 patients were included. The results of meta-analysis showed that: there were no significant differences in complete response (CR), partial response (PR), stable disease (SD), progression disease (PD), overall respond rate (ORR), median progression-free survival (mPFS), and median overall survival (mOS) between two groups (P>0.05). However, CARIRI group was lower on the disease control rate (RR=0.93, 95%CI 0.86 to 1.00, P=0.04) than CAPOX group. Incidence of diarrhea was higher in CAPIRI group (RR=1.83, 95%CI 1.37 to 2.45, P<0.000 1). However, the incidence rate of peripheral neurotoxicity in CAPOX group was higher (RR=0.13, 95%CI 0.05 to 0.35, P<0.000 1). There were no significant differences between two groups in the incidence rates of nausea and vomiting, hand-foot syndrome, anemia, thrombocytopenia, leukocytopenia and alopecia (P>0.05).ConclusionsCurrent evidence shows that two groups are equivalent in terms of curative effects. CAPIRI has a higher incidence rate of diarrhea, while CAPOX has a higher risk of peripheral neurotoxicity. Due to limited quality and quantity of the included studies, more high quality studies are required to verify above conclusions.