[Characteristics and risk factors of lymph node metastasis in pN1 stage esophageal squamous cell carcinoma]

To analyze the pattern and the clinicopathologic risk factors of lymph node metastasis (LNM) in pN1 stage esophageal squamous cell carcinoma.

Clinical data of 181 patients (154 male and 27 female patients, aging from 38 to 84 years) who underwent esophagectomy during January 2005 and December 2008 were reviewed, including 69 cases through left thoracotomy and 112 cases through right thoracotomy. All patients underwent systematic lymphadenectomy. The risk factors related to lymph node metastasis were analyzed by χ² test and Logistic regression analysis.

The relatively highest LNM site were middle and lower thoracic paraesophageal (38.4%), right and left cardiac (35.3%) and the left gastric artery (38.8%). The LNM of middle and lower thoracic paraesophageal was correlated with T stage (χ² =11.754, P=0.009). A correlation was also found among the LNM of upper mediastinum and the location of tumor (P=0.039). The T stage (χ² =8.694, P=0.034) and TNM stage (χ² =6.906, P=0.032) were the risk factors of the LNM of middle and lower mediastinum. The risk factors of the LNM of abdomen were the location of tumor, the length of tumor, T stage and TNM stage (χ² =5.713 to 16.749, P>0.05). Multivariate analysis showed that the location of tumor is the independent risk factors for the abdominal lymph node metastasis.

The relatively highest LNM sites are correlated with the location of tumor, T stage, the length of tumor and TNM stage. According to the risk factors of LNM, the relatively highest LNM sites should be mainly swept.