Meta-analysis of D1 versus D2 gastrectomy for gastric adenocarcinoma: let us move on to another era.

OBJECTIVES To conduct a meta-analysis of randomized controlled trials evaluating the efficacy and drawbacks of limited (D1) versus extended lymphadenectomy (D2) for proven gastric adenocarcinoma. METHODS A search of Cochrane, Medline, PubMed, Embase, Science Citation Index and Current Contents electronic databases identified randomized controlled trials published in the English language between 1980 and 2008 comparing the outcomes of D1 versus D2 gastrectomy for gastric adenocarcinoma. The meta-analysis was prepared in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses statement. The 6 outcome variables analyzed included length of hospital stay; overall complication rate; anastomotic leak rate; reoperation rate; 30-day mortality rate and 5-year survival rate. Random effects meta-analyses were performed using odds ratios (OR) and weighted mean differences (WMD). RESULTS Six trials totaling 1876 patients (D1 = 946, D2 = 930) were analyzed. In 5 of the 6 outcomes the summary point estimates favored D1 over D2 group with a statistically significant reduction of (i) 6.37 days reduction in hospital stay (WMD -6.37, confidence interval [CI] -10.66, -2.08, P = 0.0036); (ii) 58% reduction in relative odds of developing postoperative complications (OR 0.42, CI 0.27, 0.66, P = 0.0002); (iii) 60% reduction in anastomotic breakdown (OR 0.40, CI 0.25, 0.63, P = 0.0001); (iv) 67% reduction in reoperation rate (OR 0.33, CI 0.15, 0.72, P = 0.006); and (v) 41% reduction in 30-day mortality rate (OR 0.59, CI 0.40, 0.85, P = 0.0054). Lastly there was no significant difference in the 5-year survival (OR 0.97, CI 0.78, 1.20, P = 0.7662) between D1 and D2 gastrectomy patients. CONCLUSIONS On the basis of this meta-analysis we conclude that D1 gastrectomy is associated with significant fewer anastomotic leaks, postoperative complication rate, reoperation rate, decreased length of hospital stay and 30-day mortality rate. Finally, the 5-year survival in D1 gastrectomy patients was similar to the D2 cohort.