Parallel-group controlled trial of esophagectomy versus chemoradiotherapy in patients with clinical stage I esophageal carcinoma (JCOG0502).

7Background: Esophagectomy (E) is the standard of care for stage I esophageal squamous cell carcinoma (ESCC), while chemoradiotherapy (CRT) is a treatment option. A parallel-group controlled trial including randomized arms to confirm the non-inferiority of CRT to E for stage IA ESCC was conducted. Methods: Patients (pts) with thoracic ESCC, adenosquamous cell, or basaloid cell carcinoma with stage IA (T1bN0M0), age 20 to 75, performance status 0 to 1, and adequate organ function were eligible. If pts accepted randomization, they were randomly allocated to E with 2-3 field lymph node dissection (arm A) or CRT (arm B). However, if pts had a preference and refused randomization, they were allocated to pts preference arm, E (arm C) or CRT (arm D). CRT consisted of cisplatin and 5-FU, with radiation at the dose of 60 Gy concurrently. The primary endpoint was overall survival (OS) of arm A and B, secondary endpoint included OS of arm C and D using inverse probability weighting with propensity score. The planned...