Long-Term Outcome and Metastatic Risk After Endoscopic Resection of Superficial Esophageal Squamous Cell Carcinoma

OBJECTIVES: Long-term outcomes after endoscopic resection (ER) provide important information for the treatment of esophageal carcinoma. This study aimed to investigate the rates of survival and metastasis after ER of esophageal carcinoma. METHODS: From 1995 to 2010, 570 patients with esophageal carcinoma were treated by ER. Of these, the 402 patients with squamous cell carcinoma (280 epithelial (EP) or lamina propria (LPM) cancer, 70 muscularis mucosa (MM) cancer, and 52 submucosal (SM) cancer) were included in our analysis. Seventeen patients had cancer invading into the submucosa up to 0.2 mm (SM1) and 35 patients had cancer invading into the submucosa more than 0.2 mm (SM2). RESULTS: The mean (range) follow-up time was 50 (4–187) months. The 5-year overall survival rates of patients with EP/LPM, MM, and SM cancer were 90.5, 71.1, and 70.8%, respectively (P=0.007). Multivariate analysis identified depth of invasion and age as independent predictors of survival, with hazard ratios of 3.6 for MM cancer and 3.2 for SM cancer compared with EP/LPM cancer, and 1.07 per year of age. The cumulative 5-year metastasis rates in patients with EP/LPM, MM, SM1, and SM2 cancer were 0.4, 8.7, 7.7, and 36.2%, respectively (P<0.001). Multivariate analysis identified depth of invasion as an independent risk factor for metastasis, with hazard ratios of 13.1 for MM, 40.2 for SM1, and 196.3 for SM2 cancer compared with EP/LPM cancer. The cumulative 5-year metastasis rates in patients with mucosal cancer with and without lymphovascular involvement were 46.7 and 0.7%, respectively (P<0.0001). CONCLUSIONS: The long-term risk of metastasis after ER was mainly associated with the depth of invasion. This risk should be taken into account when considering the indications for ER.