Elemene injection as adjunctive treatment to platinum-based chemotherapy in patients with stage III/IV non-small cell lung cancer: A meta-analysis following the PRISMA guidelines

Background: Elemene injection is an anticancer Chinese patent medicine that is widely used for the treatment of advanced lung cancer. Its active ingredients are beta-, gamma- and delta-elemene, which are extracted from Curcuma aromatica Salisb. (Curcuma wenyujin Y.H. Chen & C. Ling). Purpose: To evaluate the effects of Elemene injection as adjunctive treatment to platinum-based chemotherapy (PBC) in patients with stage III/IV non-small cell lung cancer. Study design: A systematic review and meta-analysis of randomized clinical trials (RCTs). Materials and methods: A systematic review and meta-analysis were conducted following the PRISMA (Preferred Reported Items for Systematic Review and Meta-analysis) guidelines. Analyses were performed using Review Manager 5.3, Comprehensive Meta-Analysis 3.0 and Trial Sequential Analysis software. All RCTs comparing Elemene injection combined with PBC vs. PBC alone were selected and assessed for inclusion. The disease control rate (DCR) was defined as the primary endpoint, and the objective Response rate (ORR), survival rate, quality of life (QOL), cellular immune function and toxicities were the secondary outcomes. Results: 15 RCTs recruiting 1,410 patients with stage III/IV NSCLC were included. The methodological quality of most included trials was low to moderate. Compared with PBC alone, Elemene injection plus PBC can improve DCR (RR = 1.23, 95% CI 1.16 to 1.31, p < 0.00001), ORR (RR = 1.62, 95% CI 1.44 to 1.82, p < 0.00001), 1- and 2-year survival rates (RR = 1.33, 95% CI 1.11 to 1.59, p = 0.002; RR = 1.73, 95% CI 1.21 to 2.46, p = 0.002, respectively), QOL (RR = 1.91, 95% CI 1.58 to 2.32, p < 0.00001), CD4+ T cell counts (WMD = 10.43, 95% CI 8.25 to 12.62, p < 0.00001), and the CD4+/CD8+ ratio (WMD = 0.78, 95% CI 0.42 to 1.14, p < 0.0001) and can reduce severe toxicities by 58% (RR = 0.42, 95% CI 0.34 to 0.52, p < 0.00001). Conclusion: Elemene injection is a safe and effective adjunctive treatment to platinum-based chemotherapy in patients with stage III/IV NSCLC. Elemene injection can improve clinical efficacy, enhance cellular immune function and alleviate the toxicity of chemotherapy. High-quality RCTs with significant survival outcomes and longer follow-ups are warranted to confirm the results further.