[Clinical use of polymerase chain reaction in diagnosis and monitoring of malignant diseases].

The polymerase chain reaction (PCR) has revolutionized the diagnosis of leukemias, lymphomas and solid tumors over the past 10 years. This molecular method can amplify tumorspecific DNA or RNA markers by a factor of up to 1 x 10(6). Clinical applications include: (1) improvement of histologic diagnosis through the detection of clonality and definition of molecular markers specifically associated with certain disease; (2) prognostic assessment at diagnosis, with impact on initial therapeutic decisions; (3) monitoring of minimal residual disease and early detection of impending relapse after chemotherapy or bone marrow transplantation; (4) detection of residual tumor cells in bone marrow and peripheral blood stem cell harvests; (5) diagnosis of hereditary tumor syndromes. A number of these PCR assays is already incorporated in routine laboratory diagnostic procedures, especially in acute and chronic leukemias. The final goal of the clinical application of PCR is the development of risk adapted therapeutic concepts for neoplastic disease.