The efficacy and safety of compound kushen injection for adults with esophageal cancer: A meta-analysis of randomized controlled trials

Compound Kushen injection (CKI), derived from the traditional Chinese medicine Sophora flavescens, has been widely prescribed to treat a variety of cancers including esophageal cancer (ESCA) in China. This study aimed to evaluate the efficacy and safety of CKI for ESCA systematically. The protocol was registered in the PROSPERO database with No. CRD42022320503. PubMed, Embase, the Cochrane Library, Web of Science, CNKI, Wanfang Database, Clinicaltrials, and Chi-CTR were searched to select RCTs that compared CKI with other interventions for ESCA with outcome measures including clinical efficacy, complete response, quality of life (QoL), adverse events (AEs), and serious AEs (SAEs). The Cochrane Risk of Bias 2 (RoB2) tool was used to assess the quality of RCT. The overall effect sizes were estimated with odds ratios (ORs) and 95% confidence intervals (CIs) on binary outcome data. Meta-analyses were conducted to estimate effect sizes. Subgroup and sensitivity analyses on characteristics of RCTs were performed to test the robustness. Publication bias was also detected with different methods. The evidence strength was assessed with the Grading of Recommendation, Assessment, Development, and Evaluation method. This study finally included 35 RCTs with 2491 ESCA patients. The RoB of RCTs was some concern. The effect size of OR was 2.92 (95% CI [2.39, 3.57]) on clinical efficacy, 2.27 (95% CI [1.84, 2.81]) on complete response, 3.71 (95% CI [2.86, 4.80]) on QoL, 0.39 (95% CI [0.30, 0.50]) on AEs, and 0.13 (95% CI [0.07, 0.27]) on SAEs where the statistical significances (P < 0.00001) were found for all outcome measures. These overall effect sizes showed that CKI was more efficacious and safety for ESCA. Moreover, subgroup and sensitivity analyses found consistent results. Most publication bias analyses showed insignificant differences. The evidence strengths were moderate. The moderate evidence from this comprehensive PRISMA-compliant meta-analysis suggested that CKI may be a valuable alternative for adult patients with ESCA on its significant efficacy and safety. However, more RCTs of high quality with low RoB, large sample sizes, and long follow-up periods are still warranted to update the ESCA clinical guideline for physicians and policymakers in further study.