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.