Hospital and Surgeon Volume in Relation to Survival After Esophageal Cancer Surgery in a Population-Based Study

Purpose The influence of hospital and surgeon volume on survival after esophageal cancer surgery deserves clarification, particularly the prognosis after the early postoperative period. The interaction between hospital and surgeon volume, and the influence of known prognostic factors need to be taken into account. Methods A nationwide Swedish population-based cohort study of 1,335 patients with esophageal cancer who underwent esophageal resection in 1987 to 2005, with follow-up for survival until February 2011, was conducted. The associations between annual hospital volume, annual surgeon volume, and cumulative surgeon volume and risk of mortality were calculated with multivariable parametric survival analysis, providing hazard ratios (HRs) with 95% CIs. HRs were mutually adjusted for the surgery volume variables and further adjusted for the prognostic factors age, sex, comorbidity, calendar period, tumor stage, tumor histology, and neoadjuvant therapy. Results There was no independent association between annual hospital volume and overall survival, and hospital volume was not associated with short-term mortality after adjustment for hospital clustering effects. A combination of higher annual and cumulative surgeon volume reduced the mortality occurring at least 3 months after surgery (P trend < .01); the HR was 0.78 (95% CI, 0.65 to 0.92) comparing surgeons with both annual and cumulative volume above the median with those below the median. These results remained when hospital and surgeon clustering were taken into account. Conclusion Because surgeon volume rather than hospital volume independently influences the prognosis after esophageal cancer surgery, centralization of this surgery to fewer surgeons seems warranted. J Clin Oncol 31:551-557. (C) 2013 by American Society of Clinical Oncology