[Lymph node metastasis and prognostic factors for T1 esophageal cancer]

Objective: To evaluate the lymph node metastasis (LNM) pattern and related prognostic factors for T1 esophageal cancer. Methods: Clinical data of 143 cases of pT1 esophageal cancer patients (120 male and 23 female patients with median age of 60 years) who underwent esophagectomy and lymph node resection during January 2011 and July 2016 at the Department of Esophageal Cancer of Tianjin Medical University Cancer Institute and Hospital were reviewed, including 50 cases of T1a patients and 93 cases of T1b patients. The LNM pattern was analyzed and the prognostic factors related to LNM were assessed by χ² test and Logistic regression analysis. Results: Of 143 patients, 25 patients had LNM. The LNM rates were 17.5% for pT1 tumors, 16.0%(8/50) for pT1a tumors, and 22.6%(21/93) for T1b tumors. Of 25 patients with LNM, one patient had cervical metastasis, 15 patients with thoracic metastasis, and 17 patients with abdominal metastasis. The relatively highest LNM sites were laryngeal recurrent nerve (8 cases), left gastric artery (8 cases), right and left cardiac (6 cases) and thoracic paraesophageal (5 cases). Logistic regression analysis showed that the depth of tumor infiltration (OR=4.641, 95%CI: 1.279 to 16.836, P=0.020), tumor size (OR=5.301, 95%CI: 1.779 to 15.792, P=0.003), tumor location (OR=3.238, 95% CI: 1.248 to 8.401, P=0.016), and tumor differentiation (OR=5.301, 95%CI: 1.719 to 16.347, P=0.004) were independent prognostic factors related to LNM for T1 esophageal cancer. Tumor size (OR=4.117, 95% CI: 1.228 to 13.806, P=0.022) was an independent risk factor related to thoracic LNM, and the vessel invasion (OR=6.058, 95% CI: 1.228 to 29.876, P=0.027) and tumor location (OR=8.113, 95% CI: 1.785-36.872, P=0.007) were independent prognostic factors related to abdominal LNM. Conclusions: T1 esophageal cancer has a relatively high LNM rate, and the depth of tumor infiltration, tumor size, tumor location and tumor differentiation are correlated with LNM. The LNM risk and extent must be considered comprehensively in decision-making of a better surgical treatment and lymph node resection strategy.