Histopathologic findings predicting lymph node metastasis and prognosis of patients with superficial esophageal carcinoma: analysis of 240 surgically resected tumors

BACKGROUND: If it were possible to elucidate the histopathologic findings predicting lymph node metastasis and prognosis in superficial squamous cell carcinoma of the esophagus (SSCCE), they could be used as markers to identify patients who do not require additional surgical resection after endoscopic mucosal resection (EMR). METHODS: Two hundred forty surgically resected SSCCEs were examined histopathologically. Histopathologic factors including vertical tumor invasion depth in the submucosal layer (VTIDsm), degree of nuclear atypia (low, one point; high, two points), growth pattern (expansive, one point; infiltrative, two points), and histologic grade (calculated by adding the latter two scores to obtain Grade 1, two points; Grade 2, three points; and Grade 3, four points) were evaluated to investigate the associations among these factors, lymph node metastasis, and prognosis. RESULTS: No lymph node metastasis was found in 54 patients with carcinoma limited to the lamina propria. Their 5-year survival rate was 100%. Multivariate analysis of 186 carcinomas invading beyond the lamina propria showed that lymphatic permeation correlated with lymph node metastasis (P<0.0001) and the presence of lymph node metastasis and a high histologic grade were independent factors indicating a poor prognosis (P = 0.0061 and 0.023, respectively). In 53 patients whose tumors had invaded the lamina muscularis or slightly invaded the submucosa (VTIDsm <500 microm), no lymph node metastasis was found in the lymphatic permeation negative and blood vessel permeation negative patients with VTIDsm values <200 microm and histologic Grades 1 or 2. CONCLUSIONS: Lymphatic permeation is a good predictor of lymph node metastasis in patients with SSCCE. Lymph node metastasis and the histologic grade are independent prognostic factors. Vessel permeation, VTIDsm, and histologic grade were found to be important factors for identifying patients who did not require additional surgical treatment after EMR.