Impact of extended lymphadenectomy on morbidity, mortality, recurrence and 5-year survival after gastrectomy for cancer. Meta-analysis of randomized clinical trials.

PURPOSE: To compare morbidity, mortality, recurrence and 5-year survival between D1 and D2 or D3 for treatment of gastric cancer.

METHODS: Systematic review and meta-analysis of RCTs. Metaview in RevMan 4.2.8 for analysis; statistical heterogeneity by Cochran's Q test (P<0.1) and I(2) test (P>50%). Estimates of effect were calculated using random effects model.

RESULTS: D2 or D3 was associated with higher in-hospital mortality, with RR = 2.13, p=0.0004, 95% CI, 1.40 to 3.25, I(2)=0%, P=0.63; overall morbidity showed higher incidence in D2 or D3, RR = 1.98, p<0.00001, 95% CI, 1.64 to 2.38, I(2) = 33.9%, P=0.20; operating time showed longer duration in D2 or D3, weighted mean difference of 1.05, p<0.00001, 95% CI, 0.71 to 1.38, I(2) = 78.7%, P=0.03, with significant statistical heterogeneity; reoperation showed higher rate in D2 or D3, with RR = 2.33, p<0.0001, 95% CI, 1.58 to 3.44, I(2) = 0%, P=0.99; hospital stay showed longer duration in the D2 or D3, with weighted mean difference of 4.72, p<0.00001, 95% CI, 3.80 to 5.65, I(2) = 89.9%, P<0.00001; recurrence was analyzed showed lower rate in D2 or D3, with RR = 0.89, p=0.02, 95% CI, 0.80 to 0.98, I(2) = 71.0%, P = 0.03, with significant statistical heterogeneity; mortality with recurrent disease showed higher incidence in D1, with RR = 0.88, p=0.04, 95% CI, 0.78 to 0.99, I(2) =51.8%, P=0.10; 5-year survival showed no significant difference, with RR = 1.05, p=0.40, 95% CI, 0.93 to 1.19, I(2) = 49.1% and P=0.12.

CONCLUSIONS: D2 or D3 lymphadenectomy procedure is followed by higher overall morbidity and higher in-hospital mortality; D2 or D3 lymphadenectomy shows lower incidence of recurrence and lower mortality with recurrent disease, when analysed altogether with statistical heterogeneity; D2 or D3 lymphadenectomy has no significant impact on 5-year survival.