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 genetic researches and clinical application in human cancer.

This paper is intended to update researchers on the rapid advances that have been made in the understanding of prognostically significant molecular cytogenetic markers in hematological malignancies. Examples include observations of p53, RB1, and ATM gene deletions as well as 12q13 amplifications in up to 80% of patients with chronic lymphocytic leukemia (CLL) in association with significantly different prognostic groups. Greater than 80% of patients with multiple myeloma have been observed to have chromosome 13q deletions; RB1, D13S319, and p53 deletions have been reported to serve as independent adverse prognostic parameters. In chronic myelogenous leukemia (CML), large deletions (ASS and N43E1 being the two most commonly deleted loci) at the t(9;22) breakpoints have been reported to be associated with reduced time to accelerated phase; and in adult acute myelogenous leukemia (AML),  molecular cytogenetic analysis as well as CEBPA, FLT3, and RAS studies predict  the outcome of  therapy.

Key words: molecular cytogenetics; chromosomal abnormalities; hematological malignancies