Long-term survival advantage and prognostic factors associated with intraperitoneal chemotherapy treatment in advanced ovarian cancer: a gynecologic oncology group study.

PURPOSE: To determine long-term survival and associated prognostic factors after intraperitoneal (IP) chemotherapy in patients with advanced ovarian cancer.

PATIENTS AND METHODS: Data from Gynecologic Oncology Group protocols 114 and 172 were retrospectively analyzed. Cox proportional hazards regression models were used for statistical analyses.

RESULTS: In 876 patients, median follow-up was 10.7 years. Median survival with IP therapy was 61.8 months (95% CI, 55.5 to 69.5), compared with 51.4 months (95% CI, 46.0 to 58.2) for intravenous therapy. IP therapy was associated with a 23% decreased risk of death (adjusted hazard ratio [AHR], 0.77; 95% CI, 0.65 to 0.90; P = .002). IP therapy improved survival of those with gross residual (≤ 1 cm) disease (AHR, 0.75; 95% CI, 0.62 to 0.92; P = .006). Risk of death decreased by 12% for each cycle of IP chemotherapy completed (AHR, 0.88; 95% CI, 0.83 to 0.94; P < .001). Factors associated with poorer survival included: clear/mucinous versus serous histology (AHR, 2.79; 95% CI, 1.83 to 4.24; P < .001), gross residual versus no visible disease (AHR, 1.89; 95% CI, 1.48 to 2.43; P < .001), and fewer versus more cycles of IP chemotherapy (AHR, 0.88; 95% CI, 0.83 to 0.94; P < .001). Younger patients were more likely to complete the IP regimen, with a 5% decrease in probability of completion with each year of age (odds ratio, 0.95; 95% CI, 0.93 to 0.96; P < .001).

CONCLUSION: The advantage of IP over intravenous chemotherapy extends beyond 10 years. IP therapy enhanced survival of those with gross residual disease. Survival improved with increasing number of IP cycles.