Detection of occult tumor cells in resected lymph nodes of patients with stage I carcinoma and its clinicopathological significance

Abstract

Detection of tumor micrometastases in resected lymph nodes of cancer patients to obtain more reliable information concerning nodal status and its clinicopathological importance. Paraffin blocks of 3,715 resected lymph nodes from 350 Stage I cancer patients, suffering from NSCLC (n = 94), breast cancer (n = 112), esophageal cancer (n = 115), and vulvar cancer (n = 29), were re-examined by immunohisto-chemical staining, using monoclonal anti-cyokeratins (AE1/AE3), anti-EMA, and polyclonal anti-keratins antibodies. Occult nodal metastases was observed in 113 of 350 cancer patients (32.5%), and in 203 of 3,715 lymph nodes examined. The positive rates both in patients and in lymph nodes were higher in NSCLC than in others. Occult nodal metastasis was seen in 58% of pulmonary squamous-cell carcinomas and 53.8% of adenocarcinomas, while it was seen in 22.5% of esophageal and 10.3% of vulval squamous-cell carcinomas, and in 27.7% of breast adenocarcinomas (P < 0.05). Follow up of a fraction of breast cancer patients showed that the prognosis of patients with positive nodes was worse than that in patients with negative nodes (P < 0.05). The data suggested that the immunohistochemical technique can significantly facilitate the detection of micrometastatic tumor cells in lymph nodes. The frequency of occult lymph node metastasis may have significant impact on the prognosis of cancer patients.