Independent prognostication and therapy monitoring of breast cancer patients by DNA/RNA typing of minimal residual cancer cells

Clinical relevance, purification techniques and molecular characterization of minimal residual cancer cells (MRCC) is a controversial topic in the lit erature. An analytical concept including a novel isolation procedure and a panel of tests for DNA and RNA typing of MRCCs is described and clinically evaluated in this paper The purification procedure exploiting the physical characteristics of MRCCs shows superior performance lending to >50% pure an d viable tumor cells. Proof of the presence and purity of MRCCs in an isola ted sample is given by multiparametric DNA typing (amplifications, mutation s, losses of heterozygosity). On the basis of the proven presence of MRCCs tumor-relevant mRNAs can be adequately analyzed by normalized quantitative real-time RT-PCR. The molecular characterization of MRCCs isolated from blo od of breast cancer patients could have a strong clinical impact on prognos tication, drug targeting and therapy monitoring.