Abstract: [Abstracts] Background Esophagectomy is the standard procedure for esophageal carcinoma, but surgery for early esophageal carcinoma has been challenged by less invasive endoscopic approaches developing quickly. So it is definitely necessary to assess risk of lymph node metastasis before screening patients to have an operation or endoscopic therapy. Objective The aim of this study was to analysis risk factors for lymphatic metastasis in T1b esophageal squamous carcinoma and evaluate its risk. Methods Cases and pathological reports of 112 T1b esophageal squamous carcinoma were retrospectively analyzed, 80 patients(group N0) had no lymph node metastasis seen as control group and 32 patients(group N1) had lymph node metastasis seen as experimental group. Tumor specimens were reevaluated for overall submucosal layer thickness, tumor length, depth of tumor infiltration as well as lymphatic and vascular infiltration. Depth of submucosal tumor infiltration was divided in thirds (SM1, SM2, SM3) and factors influencing lymphatic metastasis were assessed. Results Univariate logistic regression analysis showed depth of tumor infiltration, tumor length and tumor differentiation were risk factors influencing lymphatic metastasis formation. Variate logistic regression analysis showed tumor differentiation was independent risk factor influencing lymphatic metastasis formation(p<0.001), and removed influence of tumor differentiation, there remaining second independent factor that remained significant was tumor infiltration(p=0.023). Conclusion Lymphatic metastasis risk of T1b esophageal squamous carcinoma is high and influencing factors is more, so esophagectomy should sequentially be the standard treatment for T1b patients prone to lymphatic metastasis.

Key words: esophageal carcinoma, T1b, lymph node, metastasis