Clinical impact of systematic pelvic and para-aortic lymphadenectomy for pT1 and pT2 ovarian cancer: a retrospective survey by the Sankai Gynecology Study Group.

Background: The therapeutic value of systematic lymphadenectomy for early-stage epithelial ovarian cancer (EOC) is controversial. This study evaluates the survival impact and adverse events of systematic pelvic and para-aortic lymphadenectomy in patients with pT1 and pT2 EOC.

Methods: A retrospective investigation was performed using data from patients with pT1 and pT2 EOC at multi-institutions belonging to the Sankai Gynecologic Study Group (SGSG). We selected patients who had undergone systematic pelvic and para-aortic lymphadenectomy (Group LA) (n = 284) and patients who had not undergone lymph node resection (Group no-LA) (n = 138). Outcomes for patients and peri-operative adverse events were compared between the two groups.

Results: The median operation time was significantly longer in Group LA (288 min) than in Group no-LA (128 min) (P < 0.0001). Total blood loss was significantly higher in Group LA, 43.7 % of patients receiving blood transfusions. There were no significant differences between the treatment groups for progression-free survival (PFS) or overall survival (OS). However, for patients with pT2, PFS was significantly longer in Group LA than in Group no-LA (P = 0.0150). Lymph node metastases were detected in 23 cases (8.1 %) and these patients had significantly shorter PFS than those without metastasis (P = 0.0409). The outcome for patients who underwent chemotherapy after surgery was significantly improved in the Group no-LA, but no improvement was observed in Group LA.

Conclusions: Systematic lymphadenectomy may improve outcomes only in pT2 EOC patients with acceptable peri-operative events. Furthermore, accurate surgical staging may avoid unnecessary adjuvant chemotherapy in selected early-stage cases.