Impact of ascites volume on clinical outcomes in ovarian cancer: A cohort study

Objectives To investigate the impact of ascites volume on ovarian cancer outcomes. Methods Clinicopathologic features of a cohort of patients with ovarian cancer were obtained from a curated database at a single institution. Progression free survival (PFS) and overall survival (OS) were recorded. Ascites volume at primary surgery was dichotomized at 2000 mL and comparisons for high and low volume ascites were made. Additionally, to elucidate interactions between ascites and ovarian tumor progression, we evaluated the effect of intraperitoneal administrations of murine cell-free ascites versus saline in a syngeneic mouse model of epithelial ovarian cancer. Results Out of 685 patients identified, 58% had ascites present at the time of initial surgery. Considering the volume of ascites continuously, each liter of ascites was associated with shorter PFS (HR = 1.12, 95% CI: 1.07–1.17) and OS (HR = 1.12, 95%CI: 1.07–1.17). Patients with ascites greater than the median of 2000 mL had significantly shorter PFS (14.5 months vs. 22.7 months; p < 0.001) and OS (27.7 months vs. 42.9 months; p < 0.001). After adjusting for stage, presence of ascites was inversely associated with ability to achieve optimal cytoreductive surgery. Consistent with these correlative results in patients, intraperitoneal administrations of murine cell-free ascites accelerated ovarian cancer progression in mice. Conclusions The volume of ascites at initial diagnosis of ovarian cancer correlated with worse PFS and OS. The effect of large volume on prognosis is likely to be in part related to reduced likelihood for complete resection of tumor (R0). If these findings are confirmed in independent studies, consideration should be made to add the presence of large volume ascites at diagnosis to the staging criteria for ovarian cancer.