Objectives The role of intraperitoneal (IP) chemotherapy in the management of advanced ovarian cancer has been controversial. We aimed to compare survival outcomes associated with IP vs intravenous (IV) chemotherapy.

Methods We reviewed the long-term survival records of 271 women with stage IIIC or IV high-grade serous ovarian cancer treated with primary cytoreductive surgery (PCS) followed by IP or intravenous (IV) chemotherapy between 2001–2015 with a minimum follow-up of 4 years. 5-year progression free (PFS) and overall survival (OS) rates were compared using Kaplan-Meier survival analysis and covariates were evaluated using Cox regression analysis.

Results Women who received IP chemotherapy after PCS (n=91) were more likely to have undergone aggressive surgery (p<0.001), longer surgery (p<0.001), and had no residual disease (p<0.001) compared to the IV arm (n=180). Median follow-up was 51.6 months. Five-year PFS was 19% vs. 18% (p=0.63) and OS was 73% vs. 44% (p=0.00016) in the IP vs. IV arms, respectively. After controlling for covariates in a multivariable model, the use of IP was no longer a significant predictor of OS in the entire cohort (p=0.12). In patients with 0 mm residual disease, PFS was 28% vs. 26% (p=0.67) and OS was 81% vs. 60% (p=0.059) in IP (n=61) vs. IV (n=69), respectively. In patients with residual of 1–9 mm, PFS was 30% vs. 48% (p=0.076) and OS was 60% vs. 43% (p=0.74) in IP (n=29) vs. IV (n=31), respectively.

Conclusions IP chemotherapy showed a trend towards improved survival over conventional IV chemotherapy, especially in patients with no residual disease.