Detection of micrometastases in histologically negative lymph nodes in esophageal cancer

Background. New molecular techniques may identify micrometastases in histol ogically negative lymph nodes and have an impact on the staging of esophage al cancer. We investigated the role of the reverse transcriptase-polymerase chain reaction (RT-PCR) assay to identify micrometastases in esophageal ca ncer. Methods. The RT-PCR assay to detect carcinoembryonic antigen (CEA) messenge r ribonucleic acid (mRNA.) was performed on lymph nodes from patients with esophageal cancer and benign esophageal disorders. The presence of CEA mRNA in lymph nodes was considered evidence of metastases. Results. Histopathologic study revealed metastases in 50 (41%) of 123 lymph nodes from 30 patients with esophageal cancer. All histologically positive lymph nodes contained CEA mRNA by RT-PCR. Of 73 histologically negative ly mph nodes, 36 (49%) contained CEA mRNA, a significant increase compared wit h the histopathologic diagnosis (p < 0.001). Lymph nodes in patients with b enign disease contained no CEA mRNA. In 10 patients, histologic stage was N O. Five of them were also negative by RT-PCR, and all are alive with only o ne recurrence. In the remaining 5 patients, RT-PCR was positive for occult lymph node metastases; 2 have died of disease, and 1 is alive with recurren t disease. Conclusions. In patients with esophageal cancer, RT-PCR detects more lymph node metastases than does histopathology. Initial follow-up suggests a posi tive RT-PCR with negative histologic findings may have poor prognostic impl ications. Further studies will be needed to confirm any clinical implicatio ns. (C) 1998 by The Society of Thoracic Surgeons.