The Prognostic Impact of Minimally Invasive Esophagectomy on Survival after Esophagectomy following a Delayed Interval after Chemoradiotherapy; A Secondary Analysis of the DICE Study

Objective: To evaluate prognostic differences between minimally invasive esophagectomy (MIE) and open esophagectomy (OE) in patients with surgery after a prolonged interval (>12 wk) following chemoradiotherapy (CRT). Background: Previously, we established that a prolonged interval after CRT prior to esophagectomy was associated with poorer long-term survival. Methods: This was an international multi-center cohort study involving seventeen tertiary centers, including patients who received CRT followed by surgery between 2010-2020. Patients undergoing MIE were defined as thoracoscopic and laparoscopic approach. Results: 428 patients (145 MIE and 283 OE) had surgery between 12 weeks and two years after CRT. Significant differences were observed in ASA grade, radiation dose, clinical T stage, and histological subtype. There were no significant differences between the groups in age, sex, BMI, pathological T or N stage, resection margin status, tumor location, surgical technique, or 90-day mortality. Survival analysis showed MIE was associated with improved survival in univariate (P=0.014), multivariate analysis after adjustment for smoking, T and N stage, and histology (HR=1.69; 95% CI 1.14 to 2.5) and propensity matched analysis (P=0.02). Further subgroup analyses by radiation dose and interval after CRT showed survival advantage for MIE, in 40-50Gy dose groups (HR=1.9; 95% CI 1.2 to 3.0), and in patients having surgery within six months of CRT (HR=1.6; 95% CI 1.1 to 2.2). Conclusion: MIE was associated with an improved overall survival compared to OE in patients with a prolonged interval from CRT to surgery. The mechanism for this observed improvement in survival remains unknown, with potential hypotheses including a reduction in complications and improved functional recovery after MIE.