Long-term outcome of esophageal mucosal squamous cell carcinoma without lymphovascular involvement after endoscopic resection

BACKGROUND. Esophageal cancer is an aggressive cancer with a reported 3-year survival of 20%. However, early-stage esophageal cancer can be cured by endoscopic resection (ER). The long-term survival of esophageal mucosal squamous cell carcinoma after ER was investigated by calculating the standard mortality rate (SMR). METHODS. From January 1995 to December 2004, 110 patients with 138 esophageal mucosal squamous cell carcinomas without lymphovascular involvement were treated by ER. Long-term survival after ER was compared with that in the general population by calculating SMR. Subgroup analysis of patients without second primary cancer diagnosed within I year before ER (subgroup A) was also performed. RESULTS. A total of 108 patients (98.2%) were followed-up completely, with a mean observation period of 4.7 (0.4-11.3) years. The cumulative 5-year survival rate of all patients and subgroup A was 79.5% and 86.6%, respectively. Overall mortality (SMR, 1.68; 95% confidence interval [CI], 1.05-2.55) and mortality from malignant tumor (SMR, 3.14; 95% CI, 1.79-5.09) was significantly higher than that in the general population. SMR of esophageal cancer was high, although it was not significantly different from that in the general population (SMR, 4.82; 95% CI, 0.06-26.81). In subgroup A overall mortality (SMR, 0.86; 95% CI, 0.41-1.57) was similar to that in the general population. CONCLUSIONS. High overall mortality in patients with esophageal mucosal cancer after ER was mainly due to elevated mortality from second primary cancer. Favorable mortality in subgroup A indicates the efficiency of ER as a curative treatment for esophageal mucosal cancer.