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

Abstract

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.

Conflict of interest statement

Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.

© 2015 by American Society of Clinical Oncology.

Figures

Fig 1.

CONSORT diagram. GOG, Gynecologic Oncology Group; IP, intraperitoneal; IV, intravenous.

Fig 2.

Long-term overall survival of patients treated with intravenous (IV) versus intraperitoneal (IP) chemotherapy (P = .04).

Fig 3.

Long-term overall survival of patients treated with intravenous (IV) versus intraperitoneal (IP) chemotherapy based on extent of residual disease (DS; P < .001). NOTE. Gross residual defined as ≤ 1 cm; micro residual defined as no visible disease.

Fig 4.

Long-term overall survival based on number of cycles of intraperitoneal (IP) therapy (P = .03). Analysis restricted to patients in Gynecologic Oncology Group (GOG) -0172 who completed all six cycles of chemotherapy (both IP and intravenous [IV] arms).

Fig A1.

Long-term overall survival after intravenous (IV) versus intraperitoneal (IP) therapy based on Gynecologic Oncology Group (GOG) protocols 0114 and 0172.