Investigating the effect of treatment at high-volume hospitals on overall survival following cytoreductive nephrectomy

Abstract

PurposeData revealed the benefit of high-volume care in many complex disease processes. Among patients undergoing nephrectomy, those receiving cytoreductive nephrectomy (CN) for metastatic renal cell cancer (mRCC) constitute a unique subset. They often have a greater medical and surgical complexity. Against this backdrop, we sought to investigate the effect of hospital volume on overall survival among patients undergoing CN for mRCC. Material and methodsWe identified 11,089 patients who received CN for mRCC in the National Cancer Database from 1998 to 2012. We ranked hospitals based on annual CN volume. Patients who received surgery in hospitals in the top vs. bottom deciles were compared. Inverse Probability of Treatment Weighting (IPTW)-adjusted Kaplan-Meier and Cox regression analyses were used to compare the primary endpoint of overall survival between balanced cohorts of patients. Secondary endpoints were 30-day mortality, 30-day readmissions, and receipt of subsequent systemic therapy. ResultsMedian follow-up was 60.39 months (interquartile range [IQR] 35.09–95.95). Median overall survival was 17.61 months (IQR 7.16–44.58). Following propensity score weighting, surgery at a high-volume hospital was associated with a decreased risk of mortality (IPTW-adjusted Cox proportional Hazard Ratio = 0.91; 95% confidence interval: 0.86–0.96). On our IPTW-adjusted Kaplan-Meier analysis, the median survival was 19.94 months (IQR 7.98–50.27) at high-volume hospitals vs. 15.97 months (IQR 6.6–41.56) at low-volume hospitals. With regard to secondary endpoints, the data did not reveal a significant advantage for treatment at a high-volume hospital. ConclusionWe found a significant association between receipt of CN at high-volume hospitals and prolonged overall survival, demonstrated by a nearly 4 month survival benefit.