Influence of facility volume on long-term survival of patients undergoing esophagectomy for esophageal cancer.

ABSTRACT

OBJECTIVE: This study investigated the influence of facility volume on long-term survival in patients with esophageal cancer treated with esophagectomy. METHODS: Patients treated with esophagectomy for cT1 3N0 3M0 adenocarcinoma or squamous cell carcinoma of the mid-distal esophagus in the National Cancer Database between 2006 and 2013 were stratified by annual facility esophagectomy volume dichotomized as more/less than both 6 and 20. Patient characteristics associated with facility volume were evaluated using logistic regression, and the influence of facility volume on survival was evaluated with Kaplan-Meier curves, Cox proportional hazards methods, and propensity matched analysis. RESULTS: Of 11,739 patients who had esophagectomy at 1018 facilities where annual volume ranged from 1 to 47.6 cases, 4262 (36.3%) were treated at 44 facilities with annual esophagectomy volume > 6 and 1515 (12.9%) were treated at 7 facilities with annual volume > 20. Higher volume was associated with significantly better 5-year survival for both annual volume > 6 (47.6% vs 40.2%; P < .001) and annual volume > 20 (47.2% vs 42.3%; P < .001), which persisted in propensity matched analyses as well as Cox multivariable analysis (hazard ratio, 0.81; 95% confidence interval, 0.74-0.89; P < .001 for facility volume > 6 and hazard ratio, 0.78; 95% confidence interval, 0.65-0.95; P = .01 for facility volume > 20). In Cox multivariable analysis that considered facility volume as a continuous variable, higher volume continued to be associated with better survival (hazard ratio, 0.93 per 5 cases; 95% CI, 0.91-0.96; P < .001). CONCLUSIONS: Esophageal cancer patients treated with esophagectomy at higher volume facilities have significantly better long-term survival than patients treated at lower volume facilities.