Background and aims: In gastric cancer, regional lymph node metastasis verified by histopathological examination is the most important prognostic factor after complete surgical tumor resection (R0). However, the prognostic value of immunohistochemically identifiable disseminated tumor cells in lymph nodes without histopathological tumor burden in patients with gastric cancer is still controversially discussed. The aim of the study was to assess the frequency and prognostic impact of minimal tumor cell spread to lymph nodes in these patients.
Patients-methods: One hundred sixty lymph nodes judged as "tumor free" on routine histopathology obtained from 58 patients with gastric adenocarcinoma were analyzed immunohistochemically using the monoclonal anti-EpCAM antibody Ber-EP4 for occult disseminated tumor cells.
Results: Tumor cells in lymph nodes were detected in 62 (38.8%) of the 160 "tumor-free" lymph nodes obtained from 39 (67.2%) patients. Multivariate Cox regression analysis confirmed the presence of disseminated tumor cells in "tumor-free" lymph nodes as an independent prognostic factor for both a significantly reduced relapse-free survival (p = 0.008) and overall survival (p = 0.009).
Conclusions: The frequent occurrence and prognostic impact of minimal disseminated tumor cells in lymph nodes of patients with gastric carcinoma support the need for a refined staging system of excised lymph nodes, which should include immunohistochemical examination.