CLINICAL USE OF THE POLYMERASE CHAIN-REAC TION FOR DIAGNOSIS AND MONITORING OF MALIGNANT DISEASES

The polymerase chain reaction (PCR) has revolutionized the diagnosis o f leukemias, lymphomas and solid tumors over the past 10 years. This m olecular method can amplify tumorspecific DNA or RNA markers by a fact or of up to 1 x 10(6). Clinical applications include: (1) improvement of histologic diagnosis through the detection of clonality and definit ion of molecular markers specifically associated with certain diseases : (2) prognostic assessment at diagnosis, with impact on initial thera peutic decisions: (3) monitoring of minimal residual disease and early detection of impending relapse after chemotherapy or bone marrow tran splantation: (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 ro utine laboratory diagnostic procedures, especially in acute and chroni c leukemias. The final goal of the clinical application of PCR is the development of risk adapted therapeutic concepts for neoplastic diseas e.