Micro-metastases in stages I and II colon cancer are a predictor of the development of distant metastases and worse disease-free survival

Approximately 30% of the patients with Dukes A/B colon carcinoma will develop loco-regional recurrence or distant metastases. The aim of this study was to evaluate if patients with micro-metastases are at higher risk for developing distant metastases and therefore a worse disease-free survival and overall survival.In the period January 2000–January 2002, 137 patients underwent curative surgery for colon cancer. When patients had a Dukes A/B colon carcinoma, additional staining and sectioning on the harvested lymph nodes were performed retrospectively. Lymph nodes were examined using 4 multilevel sections at 250-μm intervals and stained with Pan-Cytokeratin.There were 11 patients with a Dukes A and 61 patients with a Dukes B colon carcinoma. Twenty-two patients developed metastases in time (group I) whereas 50 patients did not (group II).After additional staining and sectioning 41% of the patients of group I and 16% of the patients of group II showed micro-metastases (p < 0.05).The 5-year overall survival rate in the group with micro-metastases was 62% against 79% in the group without micro-metastases. The disease-free survival (DFS) was 51% and 72% (p < 0.05), respectively.Patients with micro-metastases develop significant more distant metastases in time and have a significant worse DFS.