Clinical significance of systematic retroperitoneal lymphadenectomy during interval debulking surgery in advanced ovarian cancer patients

Objective: To investigate the clinical significance of systematic retroperitoneal lymphadenectomy during interval debulking surgery (IDS) in advanced epithelial ovarian cancer (EOC) patients. Methods: We retrospectively reviewed the medical records of 124 advanced EOC patients and analyzed the details of neoadjuvant chemotherapy (NACT), IDS, postoperative treatment, and prognoses. Results: Following IDS, 98 patients had no gross residual disease (NGRD), 15 had residual disease sized <1 cm (optimal), and 11 had residual disease sized >= 1 cm (suboptimal). Two-year overall survival (OS) and progression-free survival (PFS) rates were 88.8% and 39.8% in the NGRD group, 40.0% and 13.3% in the optimal group (p<0.001 vs. NGRD for both), and 36.3% and 0% in the suboptimal group, respectively. Five-year OS and 2-year PFS rates were 62% and 56.1% in the lymph node-negative (LN-) group and 26.2% and 24.5% in the lymph node-positive (LN+) group (p=0.0033 and p=0.0024 vs. LN-, respectively). Furthermore, survival in the LN+ group, despite surgical removal of positive nodes, was the same as that in the unknown LN status group, in which lymphadenectomy was not performed (p=0.616 and p=0.895, respectively). Multivariate analysis identified gross residual tumor during IDS (hazard ratio, 3.68; 95% confidence interval, 1.31 to 10.33 vs. NGRD) as the only independent predictor of poor OS. Conclusion: NGRD after IDS improved prognosis in advanced EOC patients treated with NACT-IDS. However, while systematic retroperitoneal lymphadenectomy during IDS may predict outcome, it does not confer therapeutic benefits.