Impact of delayed interval cytoreductive surgery on the survival of patients with advanced stage high-grade epithelial ovarian carcinoma

Objective Our objective was to use real-world data to investigate the impact of delayed interval cytoreductive surgery on the survival of patients with advanced stage high-grade ovarian carcinoma.Methods We accessed the National Cancer Database and identified patients diagnosed between 2004-2015 with advanced stage high-grade ovarian carcinoma who received neoadjuvant chemotherapy and underwent interval cytoreductive surgery. Based on timing between surgery and chemotherapy administration patients were categorized into standard (9-13.0 weeks) and delayed (13.01-26 weeks) interval cytoreductive surgery groups. Overall survival was compared with the log-rank test and a Cox model was constructed to control for a priori selected confounders.Results We identified a total of 5051 patients; 2389 (47.3%) and 2662 (52.7%) in the standard and delayed interval cytoreductive surgery groups respectively. There was no difference in complete gross resection rates (53.2% vs 54.5%, p=0.51). Patients in the delayed interval cytoreductive surgery group were less likely to undergo complex surgery (39.3% vs 45.6%, p<0.001) and had lower rates of unplanned re-admission (4.1% vs 2.6%, p=0.003). There was no difference in overall survival between the standard and delayed interval cytoreductive surgery groups, p=0.13 (median 34.3 vs 33.9 months) even after controlling for confounders (hazard ratio (HR) 1.04, 95% confidence intervals (CIs): 0.97, 1.12). There was no difference in overall survival between the two groups for patients with no gross residual (p=0.95; median overall survival 40.08 vs 39.8 months) or gross residual disease (p=0.16; median overall survival 32.89 and 32.16 months).Conclusion For patients with advanced stage ovarian cancer delayed interval cytoreductive surgery may not be associated with worse overall survival.