[Micrometastases in colonic cancers: diagnostic methods and prognostic elements]

Micrometastasis are defined by the existence of cells or groups of cells in target organs. In the particular cas of colon cancers, although lymph node involvement is frequent, metastatic medullary involvement (while rarely at the origin of identified metastasis) can also be observed. Furthermore, micrometastatics cells can be identified in the circulating blood. This research relies on recent technics of immunocytochemistry with image analysis or molecular biology technics (generally PCR or RT-PCR). It is essential to have a specific reliable marker of metastatic cells. The prognostic value of identifying micrometastasis in organs also remains to be defined.