The association between hospital case‐volume and postoperative outcomes after esophageal cancer surgery: A population‐based retrospective cohort study

BACKGROUND: Recent advances in esophageal cancer treatment require a reevaluation of the relationship between institutional case‐volume and patient outcome. The aim of this study was to analyze and update the association between surgical case‐volume and both in‐hospital and long‐term mortality after esophagectomy for esophageal cancer. METHODS: Data of all adult patients who received esophageal cancer surgery in Korea between 2004 and 2017 were extracted from the database of the National Health Insurance Service. Hospitals were categorized into three groups according to the average annual number of esophageal cancer surgery: low‐volume (<12 cases/year), medium‐volume (12–48 cases/year), and high‐volume centers (>48 cases/year). Postoperative in‐hospital and 1‐, 3‐, and 5‐year mortality were analyzed according to the categorized groups using logistic regression. RESULTS: In total, 11, 346 esophageal cancer surgeries in 122 hospitals were analyzed. In‐hospital mortality in the high‐, medium‐, and low‐volume centers were 3.4%, 6.4%, and 11.1%, respectively. In‐hospital mortality was significantly higher in low‐ volume (adjusted odds ratio, 3.91; confidence interval, 3.18–4.80; p < 0.001) and medium volume (adjusted odds ratio, 2.21; confidence interval, 1.80–2.74, p < 0.001) centers compared to high‐volume centers. Patients who received esophageal cancer surgery in a low‐or medium‐volume center also had higher 1‐, 3‐, and 5‐year mortality compared to patients who received the surgery in a high‐volume center. Conclusions Centers with lower case‐volume showed higher in‐hospital mortality and long‐term mortality after esophageal cancer surgery.