Impact of interval from primary cytoreductive surgery to initiation of adjuvant chemotherapy in advanced epithelial ovarian cancer

Objective To determine the optimal timing of adjuvant chemotherapy after primary cytoreductive surgery for advanced epithelial ovarian cancer. Methods Results In a retrospective cohort analysis, data were assessed from women with advanced epithelial ovarian carcinoma treated at Princess Margaret Cancer Centre, Toronto, Canada between 2002 and 2012, and at Samsung Medical Centre, Seoul, Korea, between 2002 and 2015. The treatment interval was defined as the time period between primary cytoreductive surgery and the first cycle of adjuvant chemotherapy. Overall, 711 women met the inclusion criteria. Among them, 247 (34.7%) had optimal cytoreduction (residual 1-9 mm), 229 (32.2%) had microscopic residual disease (0 mm), and 235 (33.1%) had suboptimal cytoreduction (>= 10 mm). The median time of treatment interval was 10 days (range 3-86 days). In the optimal (1-9 mm) group, a longer treatment interval was significantly associated with poor overall survival (hazard ratio 1.02, 95% confidence interval 1.01-1.03; P=0.001) in multivariate analysis. Treatment interval was not associated with a significant difference in overall survival in the microscopic or suboptimal residual disease groups. Conclusion Overall survival might be negatively affected by longer treatment intervals among women with advanced epithelial ovarian carcinoma.