[Direct molecular analysis of single disseminated cancer cells: a prerequisite for the development of adjuvant therapies?].

Cancer mortality has only marginally decreased in the last decades despite huge diagnostic and therapeutic efforts. Early dissemination of cancer cells has to be blamed for this finding, because ectopically residing cells are necessarily left behind by the surgeon. Consequently, this cell population has been designated as minimal residual disease that may eventually lead to systemic relapse months or years after presumed curative surgery. Paradoxically, systemic adjuvant treatments are currently administered without any precise knowledge about the target population of such drugs. Here it is argued that the direct analysis of disseminated cells may be a prerequiste for the development of future therapies since first molecular genetic data of single disseminated cancer cells suggest an excessive intercellular heterogeneity and distant relationship to the primary tumor.