Lymphatic micrometastases in patients with early esophageal adenocarcinoma
Background: Both endoscopic and surgical treatments are recommended for m3- or sm1-adenocarcinomas of the esophagus, depending on patients' lymph nodal status. Lymphatic dissemination is related to tumor infiltration depth, but varying incidences have been reported in m3- and sm1-adenocarcinomas. The study aim was to investigate whether the presence of occult tumor cells in lymph nodes could explain this variation. Methods Sixty-three node-negative (N0) patients with early esophageal adenocarcinoma (m2/m3/sm1-tumors) were included. Multilevel-sectioning of lymph nodes was performed; sections were stained by means of immunohistochemistry with cytokeratin marker CAM5.2. Two pathologists searched for micrometastases (0.2-2.0 mm) and isolated tumor cells (ITCs, <0.2 mm). Results Positive CAM5.2 staining in lymph nodes was not seen in any of the 18 m2-patients. In 2/25 m3-tumors (8.0%) an ITC was found, but no micrometastases. Tumor cells were identified in 4/20 sm1-tumors (20.0%): three micrometastases and one ITC. Median follow-up was 121 months. Two m3-patients (3.2%) died due to disease recurrence, including one patient in whom an ITC was detected. Conclusions Lymphatic migration of tumor cells was found in node-negative m3- and sm1-adenocarcinomas of the esophagus (8.0% and 20.0%, respectively). However, the clinical relevance of these occult tumor cells should become apparent from large series of endoscopically treated patients.