The study is a feasibility and validation study of the sentinel lymph node (SLN) procedure in all stages of colon cancer. If the SLN can be reliably identified, it could be submitted to a more accurate histopathological examination (multiple sections, special staining). The detection of micrometastases in the SLN (occult stage III, upstaging) is possible. Patients with micrometastases should be considered at higher risk.