Prognostic factors in clinical T1N0M0 thoracic esophageal squamous cell carcinoma invading the muscularis mucosa or submucosa

Background Multimodality treatment is widely performed for clinical T1N0M0 (UICC-TNM classification, 7th edition) thoracic esophageal squamous cell carcinoma (ESCC), but available articles regarding treatment results are limited. This study assessed the outcomes of clinical T1N0M0 thoracic ESCC invading the muscularis mucosa (MM) or submucosa (SM) treated with radiotherapy (RT) or chemoradiotherapy (CRT).