Efficacy and safety of elemene combined with chemotherapy in advanced gastric cancer A Meta-analysis

Background: Elemene is a natural compound extracted from Zingiberaceae plants, and is used in various cancer. However, the efficacy and safety elemene combined with chemotherapy in advanced gastric cancer (GC) are lack of systematic assessment. Methods: we searched the PubMed, EMBASE, Web of Science, Cochrane Library, China Academic Journals (CNKI), Chinese Science and Technology Journals (CQVIP) and Chinese Biomedical Literature databases. Randomized controlled trials (RCTs) comparing elemene plus chemotherapy with chemotherapy alone in participants with advanced GC and reporting at least one of the following outcomes were selected and assessed for inclusion. JADAD scale was used to assess the quality. Data was screened and extracted by two independent investigators. The primary clinical outcome was overall response rate (ORR); the secondary outcomes were quality of life (QOL) and adverse events (AEs). Analysis was performed using Review Manager 5.3. Results: Sixteen RCTs matched the selection criteria, which reported on 969 subjects. Risk ratios (RR) and corresponding 95% confidence intervals (CIs) were pooled for ORR, life quality based on KPS, and risk of AEs. Compared to chemotherapy alone, elemene combined with chemotherapy in the treatment of GC may increase the efficiency of ORR(RR: 1.41; 95% CI: 1.23-1.60; P < .0001), improve their life quality based on KPS (RR: 1.84; 95% CI: 1.45-2.34; P < .00001), and reduce the adverse reactions, including leukopenia(RR: 0.73; 95% CI: 0.62-0.85; P < .00001), neutropenia (RR: 0.75; 95% CI: 0.60-0.95; P = .02), anemia (RR: 0.76; 95% CI: 0.60-0.95; P = .02), thrombocytopenia (RR: 0.56; 95% CI: 0.43-0.73; P < .00001). Nausea and vomiting (RR: 0.84; 95% CI: 0.84-1.07; P = .39), diarrhea (RR: 0.69; 95% CI: 0.41-1.15; P = .15), neurotoxicity (RR: 0.77; 95% CI: 0.59-1.00; P = .05) and hepatic dysfunction (RR: 0.95; 95% CI: 0.58-1.54; P = .83) were similar between two groups. Conclusions: Elemene may have the potential to improve the efficacy and reduce the AEs of chemotherapy for gastric cancer. However, the long-term, high-quality researches with a large sample size in different populations are required.