Minimal residual disease (MRD) monitoring is of a great importance for the patients and often determines their future therapy. At present, MRD detection in patients suffering from hematologic malignancies is included in most of treatment protocols.
However, it appears that the MRD detection, sometimes described as circulating tumor cells or minimal disseminated disease, is important in patients with solid tumors as well. Molecular MRD monitoring principles include detection of specific DNA, RNA or protein markers of tumour cells, which are not present in bone marrow and/or peripheral blood cells.
High specificity and sensitivity of this specific molecular tumour marker is necessary. Quantitative MRD monitoring by means of molecular methods can determine the decrease or increase of MRD level.
In this review, we describe different molecular methods used, an overview on their advantages, limitations, and the sample quality and processing requirements. A summary of molecular markers employed in hematological and non-hematological diseases is also presented.