Causes of death by time and treatment modality in surgically treated esophageal cancer patients: a Korean nationwide study

BACKGROUND: A comprehensive evaluation of the causes of death in Asian patients with esophageal cancer (ECA) is lacking. METHODS: This population-based cohort study used data from the Korean National Health Insurance Service database. A total of 5406 patients who underwent surgical resection for ECA between 2010 and 2017 were included and matched at a ratio of 1:3 with 16 218 controls from the general population. Causes of death were identified from national mortality data and compared according to the time after surgery and treatment modalities. Cause-specific hazard ratios (csHRs) were calculated using Cox proportional hazards models with landmark analyses performed 1, 3, and 5 years after surgery. RESULTS: ECA accounted for 83% of deaths within 5 years of surgery, declining to 32% beyond 5 years. Compared with controls, patients with ECA had persistently higher risks of all causes of death (csHR, 2.42; 95% confidence intervals [CI], 2.19-2.68 beyond 5 years). Deaths from other cancers increased steadily, comprising 25.3% of deaths beyond 5 years, with the greatest risks observed in patients who received surgery and chemotherapy. Risk of cardiovascular death was overall lower than in controls but increased gradually among patients treated with surgery and radiotherapy. Risk of respiratory death increased over time, particularly in patients who received surgery, chemotherapy, and radiotherapy, with a csHR of 3.47 (95% CI, 1.77-6.80) beyond 5 years. CONCLUSIONS: Comprehensive survivorship care is essential for ECA patients. Priorities include intensive recurrence surveillance, tailored screening for second primary malignancies, and cardiopulmonary monitoring to improve long-term survival.