Detection and Clinical Significance of Lymph Node Micrometastasis Determined by Reverse Transcription-Polymerase Chain Reaction in Patients with Esophageal Carcinoma

We investigated micrometastasis in lymph nodes by detecting carcinoembryonic antigen (CEA) mRNA. A total of 400 lymph nodes obtained from 21 patients with esophageal carcinoma were examined by CEA-specific reverse transcription-polymerase chain reaction (RT-PCR). Serial sections of positive lymph nodes were reexamined histologically and immunohistologically. Twenty-seven lymph nodes of 11 patients were diagnosed as being positive by conventional histologic examination. CEA-mRNA positivity was found in 18 of 21 patients. Among 373 histologically negative nodes, 79 (21.2%) were positive for CEA mRNA. Of these, micrometastasis was detected in 2 by histological reexamination and in 11 by immunohistochemical staining using cytokeratin antibody. Two of 6 RT-PCR-positive patients (33.3%) had recurrent disease. Four of 11 patients (36.4%) whose nodal involvement was discovered by routine histological examination also had recurrent cancer. CEA-specific RT-PCR detected micrometastasis in lymph nodes at a higher rate than histological or immunohistochemical analysis of serial sections. Since the incidence of CEA-mRNA positivity is high in the lymph nodes of esophageal cancer patients except for those with early cancer, these patients should be treated with adjuvant therapy.