Treatment Facility Volume and Survival in Patients with Metastatic Renal Cell Carcinoma: A Registry-based Analysis

Abstract

Background: Higher treatment facility (TF) volume has been linked with improved oncologic treatment outcomes.

Objective: To determine the association between TF volume and overall survival in patients with metastatic renal cell carcinoma (mRCC).

Design, setting, and participants: The National Cancer Database (NCDB) was queried for all patients with mRCC with survival data available (2004-2013, cohort A). Overall survival was assessed based on TF volumes, and increasingly narrow inclusion criteria were used to confirm the cohort A association: cohort B=mRCC patients with active treatment; cohort C=mRCC patients with systemic therapy; cohort D=mRCC patients with systemic therapy at the reporting institution; and cohort E=mRCC patients with systemic therapy at the reporting institution with known liver and lung metastatic status. Sensitivity analyses were also performed on subcohorts of mRCC who never underwent a nephrectomy (C1, D1, and E1).

Outcome measurements and statistical analysis: The effect of volume on time to death (from any cause) was determined using Cox regression models, adjusting for multiple clinical pathologic factors. Volume effects (assessed continuously) were modeled using flexible cubic splines, and adjusted 1-yr survivals were obtained from the model.

Results and limitations: A total of 41 836 mRCC patients were treated at 1222 TFs. The median age was 65 yr. Of the patients, 66% were men and 79% had clear cell mRCC. Median TF volume was 2.2 patients per year (pts/yr). Across all cohorts, higher TF volume was associated with improved outcomes. Adjusted 1-yr survival in cohort A was 0.36 at 2 pts/yr, 0.39 at 5 pts/yr, 0.42 at 10 pts/yr, and 0.46 at 20 pts/yr, with similar magnitudes of effect in cohorts B-E. Limitations include the retrospective nature of NCDB analysis and the lack of information on treatment regimens used at specific facilities, which may explain mechanisms of effects.

Conclusions: Higher facility volume is associated with improvements in survival for patients being treated for mRCC. Steps should be taken to standardize management of mRCC patients, such as evidence-based pathway development, clinical trial access, and multidisciplinary resource availability at lower-volume TFs.

Patient summary: In this report, we analyzed a large cancer database and found that patients with metastatic kidney cancer survived longer if they were managed at facilities that treated a higher volume of such patients. This information can help find the best treatment environment for patients with metastatic kidney cancer.

Keywords: Cancer survival; Facility volume; Renal cell carcinoma.