Occult micrometastasis: enrichment, identification and characterization ofsingle disseminated tumour cells

The decision as to whether systemic adjuvant therapy should be applied in b reast cancer patients for secondary prevention of metastatic relapse is bas ed solely on the statistical prognosis. For this reason, the direct identif ication of minimal residual cancer in distant organs (e.g. bone marrow) is of particular importance. In breast cancer 25-43% of the patients exhibit m icrometastatic disease in bone marrow, following resection of their primary tumours. Successful enrichment, reliable identification and molecular prof iling of disseminated tumour cells at the single cell Level are still key i ssues in ongoing and future studies. In addition, first attempts have been reported to evaluate the biology of disseminated tumour cells using in vitr o and in vivo models. Taken together, the advancing characterization of dis seminated tumour cells opens the avenue for the development of new therapeu tic approaches aimed at preventing metastatic relapse.