Detection and clinical significance of micrometastases in bone marrow of patients with breast cancer

Since early 1980's it is known that in different mesenchymal organs and tissues of patients with primary operable breast cancer disseminated epithelial cells are observed. Several methodes have been used to detect those cells. First attempts were made with immunohistochemical staining using monoclonal antibodies against cell membrane epitopes or elemnts of cytoskeleton like cytokeratins. Other methodes include reverse trancriptase polymerase chain reaction, fluorescent hybrydysation in situ, negative and positive immunomagnetic selection to detect genes coding molecules typical for epithelial tissues. But so far, on the basis of results of many clinical trials it is not possible to certify that disseminated epithelial cells' preasence in bone marrow is independent prognostic factor for estimating disease free survival and overal survival. This might be due to different, uncomparable methodes of disclosing these cells used, different criteria of recruitmetn into clinical trials, small groups of patients or to short time of follow-up.
It is necessary to elaborate standarised methodes not only for detection of bone marrow metastases but for their phenotype and genotype characterisation as well. Long-term follow-up of patients after radical breast cancer treatmet with detection of epithelial cells in bone marrow could prove their independent prognostic character. It also might form the basis for individualized treatment (tailored therapy) with use of all novel anticancer strategies for example immunotherapy or gene therapy.