Efficacy of endoscopic treatment on patients with severe dysplasia/carcinoma in situ of esophageal squamous cell carcinoma: A prospective cohort study

Objective: To explore the natural history of severe dysplasia/carcinoma in situ(SD/CIS) patients and to evaluate the efficacy of endoscopic treatment to SD/CIS patients.Methods: Between January 2005 and December 2009, a population-based prospective screening program on esophageal squamous cell carcinoma(ESCC) was performed in Linzhou, China, with endoscopic screening plus iodine staining. All the eligible histologically confirmed SD/CIS patients were followed up through the door-todoor follow-up and local cancer registry. The endpoint was diagnosed as ESCC or the December 31 st, 2016.Kaplan-Meier survival analysis and Log-rank test were used to compare the survival rates among treated and untreated patients.Results: A total of 175 SD/CIS patients were enrolled and grouped by whether they received endoscopic treatment. Eleven-year cumulative incidence rates for untreated and treated SD/CIS patients were 10.7% [95%confidence interval(95% CI): 6.9-16.1] and 3.2%(95% CI: 1.4-7.0), respectively. The ESCC incidence free survival rate, and all-cause incidence and mortality free survival rates were all significantly higher in the treated patients vs. untreated patients(P=0.043, P=0.008 and P=0.015, respectively). The ESCC mortality free survival rate showed no significant differences between the two groups(P=0.847).Conclusions: The cumulative incidence rate of SD/CIS patients to ESCC was much lower than previously reported. The Kaplan-Meier survival analysis showed that endoscopic treatment could increase the ESCC and allcause disease-free survival rates of SD/CIS patients significantly.