Systematic evaluation of the safety and therapeutic effects of para-aortic lymphadenectomy for advanced gastric cancer: a systematic review and meta-analysis

OBJECTIVE: At present, there is still no definite conclusion on whether advanced gastric cancer (GC) requires additional para-aortic nodes dissection (PAND). The purpose of this study is to summarize current evidence on the potential benefits of the extended systemic lymphadenectomy (D2+) compared to D2 lymphadenectomy in the treatment of gastric cancer. MATERIALS AND METHODS: Systematic literature search was performed across PubMed, Embase, Cochrane library, Web of Science, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, VIP Database for Chinese Technical Periodicals, and China Biology Medicine disc using the following terms: gastric cancer, para-aortic lymphadenectomy, D2+ lymphadenectomy and D3 lymphadenectomy. RevMan 5.3 software was used for the meta-analysis. RESULTS: A total of 20 studies involving 5,643 patients were included, consisting of 6 randomized controlled trials (RCT) and 14 non-randomized controlled trials (nRCT). Compared with the D2 group, the operating time in the D2+ group was longer [mean difference (MD)=99.45 min, 95% confidence interval (CI) (48.93, 149.97), p<0.001], with more intra-operative blood loss [MD=262.14 mL, 95% CI (165.21, 359.07), p<0.001]. There were no significant differences in five-year overall survival (OS) [HR=1.09, 95% CI (0.95, 1.25), p=0.22] and post-operative mortality [RR=0.96, 95% CI (0.59, 1.57), p=0.88] between the two groups. The rate of post-operative complications in group D2+ was higher than that in group D2 [RR=1.42, 95% CI (1.11, 1.81), p<0.001]. CONCLUSIONS: Prophylactic D2+ surgery is not recommended, since D2+ surgery is associated with an increased rate of post-operative complications and does not improve the long-term survival rate of patients with advanced gastric cancer. However, D2+ surgery (especially D2+PAND) has certain survival advantages for specific patients, and D2+PAND surgery combined with chemotherapy may potentially improve long-term survival rate.