Abstract Background Esophageal cancer is the sixth leading cause of cancer-related death worldwide, with both high incidence and mortality rates. While esophageal adenocarcinoma is more common in Western countries and Australia, esophageal squamous cell carcinoma (ESCC) is the predominant type in Asia, including Japan. Endoscopic treatment, including endoscopic submucosal dissection (ESD), is widely accepted as a minimally invasive treatment for superficial ESCC. However, metastatic recurrence remains a concern, and the indications for endoscopic resection continue to be debated. This study aimed to identify non-curative factors in endoscopic treatment for superficial ESCC. Methods We retrospectively analyzed cases of ESCC treated with endoscopic resection at our institution between 2019 and 2024. Patients were included if the preoperative depth of invasion was diagnosed as deeper than the muscularis mucosae (MM) or deeper. We investigated the characteristics of high-risk lesions for metastasis and examined factors associated with it. Patients with a history of esophagectomy or radiotherapy for ESCC were excluded. High-risk lesions were defined as ESCC with submucosal or lymphovascular invasion. Results A total of 113 patients with 116 lesions were analyzed. Among them, 53 lesions (53 patients) were classified as the high-risk lesions, and 61 lesions (63 patients) as the low-risk group. No significant difference was found in tumor size (median 21 mm) or circumferential involvement. However, SMT-like marginal elevation was observed in 13 out of 53 lesions (24.5%) in the high-risk group, compared to 5 out of 63 lesions (7.9%) in the low-risk group, showing a significantly higher incidence in the high-risk group. The 5-year overall survival rate was 88.5% in the high-risk group and 95.3% in the low-risk group. Conclusion When assessing the depth of invasion of ESCC during endoscopic examination, special attention should be given to ESCC with SMT-like marginal elevation, as they may indicate a high risk of metastasis.
Watanabe et al. (Fri,) studied this question.