Cancer cytogenetics and molecular genetics: detection and therapeutic strategy.

It has become increasingly evident that cancers are "genetic diseases" resulting from an accumulation of inherited and environmentally-induced changes or mutations in the genome, i.e., the modification, activation, or inactivation of various genes, including oncogenes, tumor-suppressor genes, and genes related to cell death. Cancer genetics has, therefore, become a burgeoning area of both cytogenetic/molecular genetic research and practical clinical application in human cancer. This article summarizes the specific types of chromosomal and associated molecular genetic alterations in leukemia and cancer. The emphasis is on the application of cytogenetics and molecular cytogenetics as diagnostic, prognostic and therapeutic indices, as approaches to the evaluation of minimal residual disease and as guides for differentiation therapy and the molecular localization of oncogenes/tumor suppressor genes related to gene therapy in leukemias and cancers. This review is intended to update physicians of various disciplines on the rapid advances that have been made in the understanding of the chromosomal and molecular basis of cancer and in approaches for improving the management of cancer patients through knowledge of genetics.