Byeong-Chan Oh

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.

Treatment patterns and survival outcomes according to histologic subtype in malignant ovarian germ cell tumors: a nationwide real-world cohort study

Trends in the cost of ovarian cancer across phases of care and surgical years in Korea

This study aimed to estimate the medical costs among patients with ovarian cancer across distinct phases of care and surgical years. This population-based retrospective cohort study identified newly diagnosed ovarian cancer patients who underwent surgery based on nationwide claims data from Korea (2012-2019). Medical costs were categorized into 5 phases: neoadjuvant chemotherapy, surgery, frontline chemotherapy, monitoring, and recurrence. Total and cancer-related costs were analyzed by surgical year on a per patient and per patient per month (PPPM) basis. Per patient costs were estimated for each phase, with up to one year of follow-up per phase, for patients identified between 2013 and 2016. Generalized linear models (GLMs) examined associations between surgical year and cancer-related costs. Among 10,594 patients, median cancer-related costs per patient were highest in the recurrent phase ($20,548), followed by the frontline chemotherapy ($7,005), neoadjuvant chemotherapy ($5,870), surgery ($4,965), and monitoring phases ($1,906). The median surgery phase costs per patient increased from $4,254 in 2013 to $5,676 in 2016; recurrent phase costs increased from $17,289 to $26,750. GLM analysis revealed that per patient and PPPM costs significantly increased over time, particularly in the surgery and recurrent phases. Compared with the cost per patient in 2013, the cost per patient in 2016 was 27% higher for the surgery phase and 49% higher for the recurrent phase. Ovarian cancer-related costs have significantly increased over time, especially in the surgery and recurrent phases, thus highlighting the growing economic burden and the need for cost-effective care strategies.