Purpose: Lymph node metastases in esophageal cancer influences prognosis and treatment. Histologic verification of lymph node metastases by endoscopic ultrasound is limited. Minimally invasive surgical staging improves accuracy but is expensive and requires exhaustive lymph node sampling to ensure accuracy. Molecular techniques have the potential to identify micrometastases in histologically negative lymph nodes and to facilitate staging. Our objective was to investigate reverse transcriptase-polymerase chain reaction to identify messenger RNA (mRNA) for carcinoembryonic antigen as a marker of micrometastases in histologically negative lymph nodes in esophageal carcinoma.

Methods: Reverse transcriptase-polymerase chain reaction to detect carcinoembryonic antigen mRNA was performed on lymph nodes and esophageal biopsies from patients with malignant and benign disease. The presence of carcinoembryonic antigen mRNA in lymph nodes was considered evidence of metastatic cell presence. Specimens were examined histopathologically and by reverse transcriptase-polymerase chain reaction.

Results: Histopathology revealed metastases in 50 of 123 (41%) lymph nodes from 30 patients with esophageal carcinoma. All 50 histologically positive lymph nodes contained carcinoembryonic antigen mRNA by reverse transcriptase-polymerase chain reaction. In 73 histologically negative lymph nodes, 33 (49%) contained carcinoembryonic antigen mRNA. This increased the yield of metastatic lymph nodes detected histologically from 50 of 123 (41%) to 86 of 123 (70%) by reverse transcriptase-polymerase chain reaction (p<0.001). All 26 lymph nodes from benign esophageal diseases contained no carcinoembryonic antigen mRNA.

Conclusions: Reverse transcriptase-polymerase chain reaction analysis increased the number of lymph node metastases detected in esophageal cancer compared to histopathology. This could facilitate accurate staging by decreasing the extent of lymph node dissection required to confirm locoregional metastases. The clinical significance of micrometastases will require further study.