[Cancer and chromosomes]

Recent advances of cytogenetics in human hematological malignancies and solid tumors were reviewed. In leukemia and lymphoma, many non-random chromosome aberrations have been found in the last decade. Further specific chromosome aberrations, which existed usually in less than five percent of acute leukemia cases, were recently found, including t (1 ; 3) in MDS or AML M4, +der (1) t (1 ; 7) in MDS, t (1 ; 11) in AML M4 or M5 and +4 in AML M2 or M4. Recurrent chromosome deletions of 17p-, 9q- and 2p- were also found as secondary aberrations in association with tumor development. Accumulation of the data from variant translocation for the 9 ; 22, 8 ; 21 and 15 ; 17 gave us important informations of critical sites of the chromosome in leukemia development. A new trial for the simultaneous analysis of morphology, immunologic phenotype and karyotype on the same metaphase clearly demonstrated stem cell origin of leukemia in some cases, specializing the affected cell lineage. Progress in non-radioactive in situ hybridization techniques now allows approaches to the recognition of particular chromosome abnormality in metaphase and also in interphase cell by means of specific repetitive probes for each chromosome. Though a hypothesis that fragile sites may act as factors predisposing to chromosomal rearrangements have attracted attention in past few years, recent results appear to be conflicting without any direct proof. Cytogenetic studies in solid tumor have been remarkably progressed with advances of methodology. Recurrent chromosome aberrations in solid tumor were found, such as t (X ; 18) in synovial sarcoma, t (12 ; 16) in liposarcoma, and i (12p) in seminoma. Studies on the correlation between specific chromosome changes and histologic subtypes resulted in an useful orientation to the diagnosis and the therapy. Advance in cytogenetics may serve as new concepts for patho-physiology of malignant tumors and contribute to further understandings of molecular genetics in human solid tumors.