Clinical significance of lymph node micrometastasis of pN0 esophageal squamous cell carcinoma.

The lymph nodes of 59 patients with pN0 esophageal squamous cell carcinomas were examined immunohistochemically using cytokeratin (CK) antibody. Primary tumors were immunostained with cyclin D1 (CD1) and E-cadherin (E-cad) antibody. Lymph node micrometastasis (MM) was found in 39 (55.5%) patients. Tumor recurrence was found in 17 patients and all but one of them had MM. The 5-year survival rate was significantly poorer in patients with MM than in those without MM. Almost all patients with positive CD1 and negative E-cad expression had MM. The examination of CD1 and E-cad expression in primary tumors may be useful for predicting MM.