Adjuvant chemotherapy after curative resection for gastric cancer: a meta-analysis

Objective. The aim of this article is to review up-to-date clinical data published in the literature in regard to adjuvant chemotherapy in patients with gastric cancer after radical surgical resection. Materials and methods. Medline, Embase, PubMed, the Cochrane Library and CBMDisc were searched to identify data published regarding this issue from 1966 to 2013. All the calculations and statistical tests were done using RevMan5.2 software. Results. A total of 29 trials with 8580 patients met all inclusion criteria. Among them, 27 studies reported survival rates at the end of follow-ups, 64.2% alive among 3981 patients in the adjuvant chemotherapy arm and 57.3% alive among 4027 patients in the observation arm. Statistical results showed that the observation arm had a shorter disease-free survival (RR: 1.11, 95% CI: 1.07-1.15), and the treatment arm had a lower recurrence rate (RR: 0.79, 95% CI: 0.74-0.84). Leucopenia, anemia, nausea and vomiting, diarrhea, alopecia and infection occurred more frequently in the treatment arm. Adjuvant chemotherapy decreased the occurrence of peritoneum relapse [RR = 0.77, 95% CI (0.66-0.90)], lymphoid nodes relapse [RR = 0.58, 95% CI (0.45-0.75)] and local relapse [RR = 0.57, 95% CI (0.41-0.80)]. Conclusions. Adjuvant chemotherapy can improve the survival rate and disease-free survival rate and reduce the relapse rate after curative resection. Adjuvant chemotherapy cannot induce thrombocytopenia and mucositis or affect liver function. The tumor in situ recurrence and peritoneum, lymph nodes relapse decrease after chemotherapy, and patients benefit from adjuvant chemotherapy regardless of the numbers of positive lymph node, depth of local invasion, Asian or non-Asian, the length of follow-up, and numbers of cycles.