Objective: To investigate the differences and similarities of the risk factors (especially lesion size) of lymph node metastasis (LNM) between stage T1a and T1b esophageal squamous cell carcinoma (ESCC), and to further refine the indications of endoscopic radical treatment for early stage esophageal carcinoma. Methods: Retrospective analysis was performed for the patients who received esophagectomy were diagnosed with T1-stage ESCC pathologically in Fudan University Shanghai Cancer Center from January 2010 to December 2016. The clinicopathological characteristics including tumor invasion depth, tumor differentiation degree, tumor size and lymphovascular invasion, as well as follow-up data were collected. Univariate analysis and multivariate Logistic regression analysis were performed to determine the differences in independent risk factors of LNM between T1a and T1b ESCC. Results: Total of 543 patients with T1-stage ESCC were included. Poor differentiation and tumor length larger than 2 cm were independent predictors for LNM in T1b-stage patients (P = 0.002, P = 0.032), but the ones were not related to LNM in T1a-stage patients (P = 0.832, P = 0.133). Lymphovascular invasion was an independent predictor for both T1a- and T1b-stage patients (P = 0.007, P < 0.001), respectively. Survival analysis showed no significant differences in relapse-free survival (RFS) between endoscopic R0 resection and esophagectomy for T1a-stage ESCC patients with tumor length >2 cm (P = 0.140). In T1a- stage ESCC, the tumor invasion of lamina muscularis mucosa (Tm3) was an independent risk factor of LNM (P = 0.031). Conclusion: The risk factors of LNM are different in stage T1a and T1b ESCC patients after endoscopic R0 resection, and which should be treated wisely.

Objective    To evaluate the strategy of chemoradiotherapy following endoscopic R0 resection for esophageal cancer in M3-T1b stage. Methods    There were 45 esophageal cancer patients with M3-T1b stage with endoscopic R0 resection followed by additional chemoradiotherapy from ECETC (Esophageal Cancer Endoscopic Therapy Consortium) as a trial group with 34 males and 11 females at age of 61.37±7.14 years. There were 90 patients with esophagectomy from Fudan University Shanghai Cancer Center as a control group with 63 males and 27 females at age of 61.04±8.17 years. Propensity score match (1:2) was used to balance the factors: gender, age, position, depth of invasion and lymphovascular invasion (LVI), which may influence the outcomes. Overall survival (OS) rate, relapse free survival (RFS) rate, and local recurrence rate were compared between the two groups. Result    There was no statistical difference (HR=2.66 with 95%CI 0.87 to 8.11, P=0.179) in terms of OS rate between the two groups. One, two and three years overall survival rate of patients in the control group was 93%, 86%, and 84%, respectively. Nobody died in the trial group within 3 years after surgery. The RFS rate between the two groups didn’t significantly differ (HR=1.48, 95% CI 0.66 to 3.33, P=0.389). One, two and three years RFS rate of patients in the contorl group was 87%, 78%, and 76%, respectively, while 97%, 93%, and 73% in the trial group, respectively. The local recurrence rates between the two groups didn’t significantly differ either ( HR=0.53，95%CI 0.13 to 2.18, P=0.314). One, two and three years local recurrence rate of patients in the control group was 5%, 6% and 6%, respectively, while 0%, 0% and 21% in the trial group, respectively. Conclusion    Similar outcomes are found regarding OS, RFS and local recurrence rates between the two groups. The strategy of endoscopic R0 resection followed by additional chemoradiotherapy has prospect for the treatment of esophageal cancer in M3-T1b stage. And this kind of therapy may be provided for those with risk factors or can not tolerate surgery.