Facility patient volume and survival among individuals diagnosed with malignant central nervous system tumors

Prior research indicates that the volume of central nervous system (CNS) tumor patients seen by a facility is associated with outcomes. However, most studies have focused on short-term survival and specific CNS tumor subtypes. Our objective was to examine whether facility CNS tumor patient volume is associated with longer-term CNS tumor survival overall and by subtype.

We obtained National Cancer Database (NCDB) data including individuals diagnosed with CNS tumors from 2004 to 2016. Analyses were stratified by age group (0-14, 15-39, 40-64, and ≥ 65 years) and tumor type. We used Cox Proportional Hazards (PH) regression and restricted mean survival time (RMST) analyses to examine associations between survival and facility patient volume percentile category adjusting for potential confounding factors.

Our analytic dataset included data from 130,830 individuals diagnosed with malignant first primary CNS tumors. We found a consistently reduced hazard rate of death across age groups for individuals reported by higher vs. lower (> 95th vs. ≤ 70th percentile) volume facilities (hazard ratio (HR)_0-14 = 0.78, 95% confidence interval (CI) 0.64-0.95; HR_15-39 = 0.87, 95% CI 0.78-0.96; HR_40-64 = 0.82, 95% CI 0.76-0.88; HR_≥65 = 0.80, 95% CI 0.75-0.86). Significantly longer survival times within 5 years for higher vs. lower volume facilities were observed ranging from 1.20 months (15-39) to 3.08 months (40-64) higher. Associations varied by CNS tumor subtype for all age groups.

These results suggest facility factors influence CNS tumor survival with longer survival for patients reported by higher volume facilities. Understanding these factors will be critical to developing strategies that eliminate modifiable differences in survival times.