Occult lymph node metastases as a predictor of tumor relapse in patients with node-negative esophageal carcinoma

Esophageal carcinoma is an aggressive disease with a very poor prognosis. Early tumor relapse after surgical resection in patients with node-negative esophageal carcinoma suggests that occult metastases may have been missed at the original pathologic examination. The aim of this study was to determine the prevalence of immunohistochemically detected occult lymph node microscopic metastases in patients with pathologic N0 esophageal carcinoma and the impact of these occult metastases on relapse-free survival.

All patients (n = 124) with pathologic N0 esophageal carcinoma undergoing resection at our institution between January, 1994, and October, 1998, constituted the study population. Esophagectomy specimens were reevaluated by immunohistochemistry (monoclonal antibody against cytokeratin AE1/AE3). Clinical and pathologic features were summarized, and patient relapse-free survival was estimated.

Among the total of 124 patients, occult lymph node microscopic metastases were identified by immunohistochemistry in 14 patients (11%) (T1 mucosa, 4%; T1 submucosa, 6%; T2, 22%; and T3, 14%). Patients were followed for a median of 3.2 years. Relapse-free survival was not significantly associated with the presence of occult lymph node microscopic metastases as detected by immunohistochemistry (P = 0.12). Advanced T stage (T3; P < 0.001) and lymphovascular invasion (P < 0.001) were found to be associated with tumor relapse.

In the present study, occult lymph node microscopic metastases in pathologic N0 esophageal carcinoma patients were less frequent than previously reported. T stage and lymphovascular invasion were significantly associated with relapse-free survival, although a significant association with occult lymph node metastases was not detected.