Immunocytochemical and molecular strategies for the detection of micrometastases in patients with solid epithelial tumours: a review.

Abstract

This review focuses on diagnostic approaches to identify patients with minimal residual epithelial cancer. Epithelial malignancies are the most common forms of cancer in Western industrialized countries. The failure to reduce the mortality of patients with epithelial tumours is probably a result of the early dissemination of cancer cells to secondary sites, which is usually missed by conventional diagnostic procedures used for tumour staging. Therefore, over the past 10 years, sensitive assays have been developed to detect individual carcinoma cells disseminated to regional lymph nodes or distant organs. Among the distant organs, the bone marrow has been identified as the most important site for the detection of haematogeneously spread cancer cells. With regard to detection techniques, most investigators have used either immunocytochemical assays with a variety of 'epithelial-specific' cytoskeleton and membrane antigens, or molecular methods based on the polymerase-chain reaction. At present, almost all data on the prognostic significance of micrometastatic cells in bone marrow are based on immunocytochemical analyses, whereas the promising new molecular assays still need to be validated in clinical trials.