The Chromosomes in Human Cancer and Leukemia

The past decade has witnessed significant advances in our understanding of some aspects of cancer biology, especially the genetic changes in cancer cells. During this period, the critical role of chromosome changes in the complex process of malignant transformation has received further recognition. For years, the cytogenetic database has been tapped by molecular biologists who have used the information as a starting point to tackle problems at the molecular level. Cytogenetic analysis was the key to defining two major categories of genetic rearrangements, namely, recurring chromosomal translocations and consistent deletions. These abnormalities have now been shown to contribute to the oncogenic process through either the modification and activation of cellular protooncogenes or the inactivation of tumor suppressor genes. Clinicians have also used cytogenetic information to assign prognosis in acute leukemia, lymphoma, and certain solid tumors. Thus, the karyotypic picture of any particular tumor has become of value to clinicians, biologists