Systematic Evaluation of the Safety and Therapeutic Effects of Para-aortic Lymphadenectomy for Advanced Gastric Cancer: a Systematic Review and Meta-analysis

Abstract Background: At present, there is still no definite conclusion on whether advanced gastric cancer requires additional para-aortic nodes dissection (PAND). The purpose of this study is an attempt to provide significant data to guide clinical decision-making. Methods: The literature was searched using the terms of gastric cancer, para-aortic lymphadenectomy and D2+ lymphadenectomy and D3 lymphadenectomy. The databases searched included 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. RevMan 5.3 software was used for the meta-analysis.Results: In total, 20 studies were included, consisting of 6 randomized controlled trials (RCT) and 14 non-randomized controlled trials (nRCT). These studies involved 5643 patients. The meta-analysis showed the following results: (1) compared with group D2 (D2 lymphadenectomy), the operating time in group D2+ (D2+ lymphadenectomy) 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]; (2) there were no significant differences in five-year overall survival [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; (3) the rate of post-operative complication in group D2+ was higher than that in group D2 [RR=1.42, 95%CI (1.11, 1.81), P<0.001]. Conclusions: It is noteworthy that the combination of perioperative chemotherapy and D2+ surgery, particularly D2+ PAND, shows some survival advantages for specific patients. Although prophylactic D2+ surgery is not recommended as it increases postoperative complications and does not improve long-term survival in patients with advanced gastric cancer.