Systematic lymphadenectomy for survival in epithelial ovarian cancer: a meta-analysis.

BACKGROUND The role of systematic lymphadenectomy (SL) remains unclear for improving overall survival (OS) in epithelial ovarian cancer (EOC). To evaluate the role of SL in EOC, we performed a meta-analysis for comparing the efficacy for OS between SL and unsystematic lymphadenectomy (USL). METHODS After the extensive literature search between January 1995 and December 2008, we analyzed 9 studies (2 randomized controlled trials [RCTs] and 7 observational studies) with 21,919 patients with EOC who underwent staging laparotomy including SL or USL. RESULTS Although SL was a favorable factor for OS compared with USL (hazard ratio [HR], 0.72; 95% confidence interval [CI], 0.68-0.76), the efficacy of SL on increased OS could not be determined in all-stage and early-stage EOC owing to the lack of RCTs and the deviation of weight by large-scale observational studies, whereas SL improved OS in advanced-stage EOC (HR, 0.70; 95% CI, 0.67-0.75). Moreover, SL increased OS in patients with all-stage disease who underwent optimal debulking surgery (HR, 0.84; 95% CI, 0.69-0.99), whereas it could not improve OS statistically in early-stage and advanced-stage diseases. However, SL showed increased OS with marginal significance in advanced-stage EOC patients treated with optimal debulking surgery (HR, 0.82; 95% CI, 0.66-1.02). CONCLUSIONS These findings suggest the possibility that SL can improve OS in advanced-stage EOC. However, the efficacy of SL on OS is still unknown because of the lack of RCTs, which requires more relevant studies for investigating the role of SL in EOC.