Adequate gross resection margin length ensuring pathologically complete resection in gastrectomy for gastric cancer: A systematic review and meta-analysis.

Aim: A positive resection margin (RM) is associated with poor survival after gastrectomy for gastric cancer (GC). However, the adequate RM length to avoid a positive RM remains controversial. We performed a systematic review to examine the RM length required to avoid a positive RM in gastrectomy for GC. Methods: This systematic review involved all relevant articles identified in PubMed, the Cochrane Library, Web of Science, and ClinicalTrials.gov until August 2023. The incidence of a positive RM related to the RM length and the possible incidence of a positive RM estimated from the discrepancy between the gross and pathological RM length were evaluated. The Newcastle-Ottawa Scale was used to quantify study quality. Results: Thirteen studies involving 8983 patients were analyzed. Investigation of the incidence of a positive RM in relation to the RM length showed that a proximal RM length of 6 cm guaranteed a negative RM in gastrectomy. Analyses of the possible incidence of a positive RM revealed that a negative RM would be guaranteed if the proximal RM length was 6 cm in distal gastrectomy, if the esophageal resection length was 2 cm in total gastrectomy for GC without esophageal invasion and 2.5 cm in total or proximal gastrectomy for GC with esophageal invasion or esophagogastric junction cancer, and if the distal RM length was 4 cm in proximal gastrectomy for early GC. Conclusions: The adequate RM lengths to ensure a pathologically negative RM in each type of gastrectomy for GC were herein suggested.