Frequent incidence of double minute chromosomes in cancers, with special up-to-date reference to leukemia.

Double minute chromosomes (DMs) are small chromatin bodies consisting of gene amplification in an extrachromosomal location. Although found in an variety of human tumor cells, their presence in hematologic malignancies is rare and their role in leukemogenesis is controversial. However, they are thought to be involved in tumorigenesis and in drug resistance, representing a mechanism for upregulated oncogene expression generally associated with a poor prognosis. The presence of DMs has been associated with a rapid disease course, low response rate, and short survival. Little knowledge is, however, available on DMs in leukemias. To elucidate this issue, a web-based search for all types of articles published was initiated using MEDLINE/PubMed, the Mitelman database and other pertinent references on websites. We found that DMs have the highest frequency in adrenal carcinoma (28.6%), and lowest rate noted as 2.6% for large intestine. The large Mitelman database and other web based pertinent reports provide novel knowledge of DMs and their association in the wide field of cancers.