Supplementary Material for: Clinicopathological characteristics and survival outcomes in patients with advanced esophageal squamous cell carcinoma who were intraoperatively diagnosed non-curative

Introduction: Curative esophagectomy is not always possible in patients with locally advanced esophageal cancer. However, few studies have investigated patients who underwent non-curative surgery with intraoperative judgment. This study aimed to investigate patient characteristics and clinical outcomes for patients undergoing non-curative surgery and compare them between non-resectional and non-radical surgery.
Methods: Among 989 consecutive patients with thoracic esophageal squamous cell carcinoma (ESCC) who were preoperatively expected for curative esophagectomy, 66 who were eligible for non-curative surgery were included in this study.
Results: Intraoperative diagnosis of T4b accounted for 93% of the reasons for the failure of curative surgery. In those patients, esophageal cancer locally invaded into the aortobronchial constriction (70%), trachea (25%), or pulmonary vein (5%). LN metastasis mainly invaded into the trachea (50%), or bronchus (28%).The overall survival of patients with non-curative surgery was 51.5%, 25.7%, and 10.4% at 6, 12, and 24 months after surgery, respectively. Although there were no differences in preoperative patient characteristics between non-resectional and non-radical surgery, distant metastasis, especially pleural dissemination, was significantly observed in T4b patients due to esophageal cancer with non-radical surgery than those with non-resectional surgery (35% vs. 15%, P=0.002). Even in patients with non-curative surgery, R1 resection and postoperative CRT were identified as independent factors for survival 1 year after surgery (P=0.047, and 0.019).
Conclusions: T4b tumor located in aortobronchial constriction or trachea/bronchus makes it difficult to diagnose whether it is resectable or unresectable. Moreover, surgical procedures and perioperative treatment were deeply associated with the clinical outcomes.