S427 Predictors for Lymph Node Metastasis and Survival of Patients With T1b Esophageal Adenocarcinoma Treated With Surgery and Endoscopic Therapy: An Analysis of Surveillance, Epidemiology, and End Results Database

Abstract

Introduction: There have been a few population-based studies to compare the long-term outcomes of patients those received surgery versus with endotherapy (ET) for T1b esophageal adenocarcinoma (EAC). In this study, we aimed to determine the risk factors of lymph node metastasis (LNM) and evaluate the long-term survival of patients with T1b EAC who underwent ET or surgery. Methods: We used the Surveillance Epidemiology and End Result database to identify patients with T1b histologically confirmed EAC diagnosed between 2004-2018. Patients were grouped based on whether they received ET (n=185) or surgery (n=935). Prevalence of LNM at initial diagnosis was analyzed. Multivariate logistic regression was performed to identify factors associated with LNM and endoscopic therapy. A Cox proportional hazards model was performed to examine the association of treatment options and survival after controlling for potential confounders. Results: Overall, 16% of cases had LNM at the time of diagnosis. The risk factors for LNM included lesion size ≥20 mm (OR 1.7, 95%CI 1.2-2.4) and poor tumor differentiation (OR 1.6, 95%CI 1.2-2.3). The use of ET increased progressively, from 0.8% in 2008 to 1.6% in 2018. ET was more commonly performed in patients with age >65 yr (OR 2.7, 95%CI 1.5-4.6), tumor size ≤20mm (OR 2.1, 95%CI 1.3-3.7), recent year of diagnosis (2008-2018 vs 2004-2007; OR 3.1, 95%CI 1.7-5.7) and those without LNM. Three-year overall survival was higher in surgery group than in the ET group (65.4% vs 54.4%, p = 0.04). Of 946 patients with T1bN0M0 EAC, 177 underwent ET and 769 had radical surgery. After adjusting for patient and tumor specific factors, patients with T1bN0M0 EAC treated by ET had a worse overall survival outcome (HR 1.4, 95% CI 1.06-1.97, P=0.01) compared to those received surgery. ET and surgery resulted in statistically equivalent in esophageal cancer mortality [HR 0.98, 95%CI 0.62-1.56, P=0.96]. Conclusion: In T1b EAC, tumor size ≥20mm and poor differentiation are the significant risk factors for LNM. Cancer specific survival in patients with T1bN0M0 EAC treated with ET appears to be similar to those treated with surgery. We found that patients who have significant coexisting conditions such as older age, are less likely to undergo surgery, as reflected in our study that older patients were more likely to have ET, which could partly explain higher overall mortality in ET group.Figure 1.: A: In a multivariate Cox proportional hazards model, adjusted for clinical and tumor-related factors, ET was associated with increased cumulative hazard (HR 1.4, 95% CI 1.06-1.97) compared to surgery. B: No difference was noted in cancer specific survival between the treatment groups when adjusted for age, sex, race, tumor size, tumor differentiation, and year of diagnosis.