Volume over location: prioritizing case volume over regional distribution in ovarian cancer treatment

The aim of this study was to examine the impact of hospital surgical volume and hospital region on overall survival (OS) in patients with ovarian cancer.

This retrospective cohort study utilized nationwide claims data from Korea (2012-2020) to analyze ovarian cancer patients who underwent surgery. Hospitals were classified as high-volume (≥20) or low-volume (<20) based on the annual volume of upfront ovarian cancer surgeries. Propensity score matching (PSM) (1:1) addressed confounder imbalances between the groups. OS was assessed via Kaplan-Meier analysis, log-rank tests, and Cox regression, with subgroup analyses by cancer stage.

A total of 11,510 patients were included in the cohort (high-volume: 8,241; low-volume: 3,269), with 3,236 matched pairs identified through PSM. Compared with low-volume hospitals, treatment at high-volume hospitals was associated with a 21% reduction in mortality risk (adjusted hazard ratio [aHR]=0.79; 95% confidence interval [CI]=0.70-0.89). This survival advantage persisted across localized/regional (aHR=0.77; 95% CI=0.63-0.95) and distant-stage disease (aHR=0.81; 95% CI=0.71-0.92). In contrast, hospital location (capital vs. noncapital) was not significantly associated with OS in the entire cohort (aHR=1.09; 95% CI=0.97-1.21) or in stage-specific analyses.

These findings highlight that instead of simply distributing hospitals geographically, establishing high-volume surgical centers is crucial to improving survival outcomes for patients with ovarian cancer.