Chromosomes and causation of human cancer and leukemia. XI. Correlation of karyotypes with clinical features of acute myeloblastic leukemia.

Acute myeloblastic leukemia (AML) patients with chromosomal abnormalities in their bone marrow cells were divided into those with minor karyotypic abnormalities (MIKA) and those with major karyotypic abnormalities (MAKA). One of the largest subgroups in the MIKA group was shown to have cytologic characteristics typical of so-called "classical" AML and a "prototypic" karyotype, which has been shown to be due to translocation between chromosomes number 8 and number 21. A missing Y chromosome in AML was mostly associated with this karyotype. Patients of the MAKA group were usually erythroleukemic, had no or very few normal metaphases among the abnormal ones in the marrow, and almost invariably showed karyotypic instability. Karyotypic differences did not affect the patients' survival after the initiation of chemotherapy as much as did the presence or absence of normal metaphases. However, the karyotypes do appear to be relevant to the decision as to whether a patient should be administered chemotherapy when no normal metaphases are found on the initial bone marrow examination.