The prognostic significance of lymph node micrometastasis in patients with esophageal carcinoma

Abstract

Lymph node metastasis is a well known feature of poor prognosis in patients with esophageal adenocarcinoma and squamous cell carcinoma. However, a significant proportion of apparently lymph node negative patients die early of metastatic disease. The aim of this study was to determine the prevalence and prognostic significance of occult lymph node metastasis in patients with esophageal adenocarcinoma and squamous cell carcinoma. Lymph node sections from esophagectomy specimens of 78 patients with lymph node negative esophageal carcinoma (49 patients with adenocarcinoma and 29 with squamous cell carcinoma) were cut serially, it toto, and immunostained with the cytokeratin antibody AE1/AE3 and evaluated for occult lymph node metastasis. The results were correlated with the clinical and pathologic features and with patient survival. Fifteen of 49 patients (31%) with adenocarcinoma and 5 of 29 patients (17%) with squamous cell carcinoma had occult lymph node metastasis detected by cytokeratin staining. In the adenocarcinoma patients, the presence of occult lymph node metastasis showed a significant correlation with increasing depth of invasion, but was not associated significantly with any other clinical or pathologic feature. In the squamous cell carcinoma patients, the presence of occult lymph node metastasis did not correlate significantly with any clinical or pathologic parameter, except that patients with occult lymph node metastasis were more likely to have received preoperative chemotherapy or radiation therapy. Occult lymph node metastasis did not correlate with poorer survival rates in patients with either adenocarcinoma (Cox proportional hazards ratio: 1.42; P - 0.46) or squamous cell carcinoma (Cox proportional hazards ratio: 0.86; P = 0.90). Occult lymph node metastasis is not an independent poor prognostic feature in esophageal adenocarcinoma or squamous cell carcinoma. Therefore, the authors do not recommend extensive lymph node sectioning with keratin immunostaining for prognostication of patients with these malignancies.