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.