LION: Lymphadenectomy in ovarian neoplasms—A prospective randomized AGO study group led gynecologic cancer intergroup trial.

5500 Background: So far, there is no level-1 evidence regarding the role of systematic pelvic and para-aortic lymphadenectomy (LNE) in patients with advanced ovarian cancer (AOC) with macroscopic complete resection und clinically negative lymph nodes (LN). Therefore, surgical management regarding LNE worldwide is very heterogeneous. Methods: Prospective randomized trial including patients with newly diagnosed AOC FIGO IIB-IV with macroscopic complete resection and pre- and intra-operatively clinical negative LN were randomized intra-operatively to LNE versus no-LNE. All centers had to qualify regarding surgical skills before participation in this trial. The primary endpoint was overall survival. Results: 647 patients were randomized between 12/08 and 1/12 to LNE (n=323) or no-LNE (n=324). The median number of removed LN in patients randomized to LNE was 57 (pelvic 35 and para-aortic22). Post-op platinum-taxane based chemotherapy was applied in 85% of the patients in the no-LNE arm and 80% in the LNE arm. Microscopic metastases were diagnosed in 56% of the pts in the LNE arm. Median OS in the no-LNE arm was 69 months and 66 months in the LNE arm (HR 1.06, 95%CI 0.83-1.34, p=0.65) and the median PFS was 26 months in both arms (HR 1.11, 95%CI 0.92-1.34 p=0.30). Surgery in the LNE arm was 64 minutes longer (means: 352 vs 288 min), resulted in a higher median blood loss (650 vs 500 ml), and a higher transfusion rate (67% vs 59%). Furthermore, serious post-operative complications occurred more frequently in the LNE arm (e.g. rate of re-laparotomies 12.1% vs 5.9% [p=0.006], hospital re-admittance rate 8.0% vs 3.1% [p=0.006] and deaths within 60 days after surgery 3.1 vs 0.9% [p=0.049]). Conclusions: Systematic pelvic and para-aortic LNE in patients with AOC with both intra-abdominal complete resection and clinically negative LN neither improve overall nor progression-free survival despite detecting (and removing) sub-clinical retroperitoneal lymph node metastases in 56% of the patients. Our data indicate that systematic LNE of clinical negative LN in patients with AOC and complete resection should be omitted to reduce post-operative morbidity and mortality. Clinical trial information: NCT00712218.