Role of lymphadenectomy in advanced ovarian cancer-a subgroup analysis of the patients excluded from the LION trial (the Charité cohort).

Objective: The phase III LION trial found no therapeutic benefit from systematic lymphadenectomy in patients with advanced ovarian cancer with optimal upfront cytoreduction and normal-appearing lymph nodes. Patients were randomized intra-operatively, excluding those who could not be operated on when they were tumor-free or had suspicious/bulky lymph nodes upon inspection or palpation. This analysis focused on the outcomes of the group excluded because of bulky lymph nodes alone.

Methods: This was a monocentric, retrospective subgroup analysis of a randomized controlled trial conducted at Charité University Hospital. We evaluated the same patients as in the LION trial. Tumor-free patients with presumed bulky/suspicious lymph nodes underwent full systematic lymphadenectomy after exclusion. Patients were analyzed according to the same endpoints as the LION trial and compared with those of the original study.

Results: Overall, 202 patients with a median age of 61 years (range; 37-74) were included; 83.6% had stage III/IV disease (n = 122) and predominantly high-grade serous histology (72%, n = 145). The rate of complete tumor resection was significantly lower in intra-operatively excluded patients (45%, n = 55) than in those included (92%, n = 112), with a significant negative impact on overall and progression-free survival (p = .042). Only 60% (n = 33) of the originally excluded patients had histologically positive lymph nodes, although 38.8% (n = 21) were presumed to be bulky by the surgeon. There was no significant difference in progression-free survival or overall survival between the patients who underwent optimal surgery and were excluded from the original LION study versus those included, regardless of their histological lymph node status and whether a lymphadenectomy was performed (p = .4, 95% CI 24.8 to 39).

Conclusion: Patients with ovarian cancer, when operated on upfront without macroscopic residual disease, have the same survival regardless of whether they have bulky nodes as long as any bulky lymph nodes are removed. Moreover, we demonstrated that intra-operative lymph node evaluation by a surgeon is subjective and often inaccurate.