Aggressive surgery for advanced ovarian cancer decreases the risk of intraperitoneal recurrence
This study investigated the pattern of first recurrence of advanced ovarian cancer before and after the introduction of aggressive surgery. We investigated 291 patients with stage III/IV epithelial ovarian, fallopian tube, and peritoneal cancer. Aggressive surgery including gastrointestinal and upper abdominal surgeries was introduced for advanced ovarian cancer in 2008. The site and time until first recurrence were compared between 70 patients treated without aggressive surgery (2000-2007) and 221 patients who underwent aggressive surgery (2008-2016). The intraperitoneal recurrence rate was significantly lower in patients treated during 2008-2016 than in patients treated during 2000-2007 (55% [82/149] vs. 81% [46/57], p < 0.001). The median time to intraperitoneal recurrence was significantly longer during 2008-2016 than during 2000-2007 (36.2 months, 95% confidence interval [CI] 31.7-60.0 vs. 14.6 months, 95% CI 11.3-20.1, log-rank test: p < 0.001). However, extraperitoneal recurrence rate was significantly higher during 2008-2016 than during 2000-2007 (27% [40/149] vs. 2% [1/57], p < 0.001). Extraperitoneal recurrence occurred during 2008-2016 in the pleura/lungs and the para-aortic lymph nodes above the renal vessels. Cox proportional hazards regression analysis revealed that treatment period (HR 0.49, 95% CI 0.34-0.71, p < 0.001) and bevacizumab use (HR 0.58, 95% CI 0.39-0.87, p = 0.009) were independently associated with intraperitoneal recurrence; stage IV disease (HR 1.87, 95% CI 1.14-3.06, p = 0.034) was independently associated with extraperitoneal recurrence. Aggressive surgery reduced intraperitoneal recurrence and prolonged time to recurrence, contributing to better patient survival.