Lymph node size as a simple prognostic factor in node negative colon cancer and an alternative thesis to stage migration.

Background: Stage migration is an accepted explanation for the association between lymph node (LN) yield and outcome in colon cancer. To investigate whether the alternative thesis of immune response is more likely, we performed a retrospective study.

Methods: We enrolled 239 cases of node negative cancers, which were categorized according to the number of LNs with diameters larger than 5 mm (LN5) into the groups LN5-very low (0 to 1 LN5), LN5-low (2 to 5 LN5), and LN5-high (≥6 LN5).