MICROMETASTASIS IN COLORECTAL-CARCINOMA - A REVIEW

Lymph node metastasis is the most important predictor of prognosis, af ter surgery, in colorectal carcinoma. The term ''micrometastasis'' has evolved from a morphological definition to one that is used with mole cular-based techniques. We review the literature to evaluate the signi ficance of detecting micrometastases in colorectal carcinoma, either b y morphological or molecular techniques, and address technical difficu lties encountered with both. Routine use of immunohistochemistry is no t recommended as most studies show little change in staging or prognos is. Radioimmunoguided surgery may prove beneficial, but problems of fa lse positives in benign diseases need to be addressed. Immunohistochem ical detection of micrometastatic deposits in bone marrow aspirates ho lds the most promise for clinical practice. Molecular techniques are m ore sensitive than immunohistochemistry, but prognostic value needs to be determined. Molecular diagnostics can also determine genetic alter ations and mutations that should improve our understanding of metastat ic colon cancer and staging accuracy. (C) 1998 Wiley-Liss, Inc.