5. 急性骨髄性白血病治療指針としての染色体の意義

抄録

Utilization of chromosomal findings in the decision to treat or not to treat AML (acute myelogenous leukemia) or ANLL (acute nonlymphocytic leukemia) is introduced. Patients over 70 years of age should not be treated because of the high risk of the treatment related death. Chromosomal findings of bone marrow cells are useful in patients younger than 70 years old. In the latter age group, patients with an n-marrow (a bone marrow with normal metaphases only) or an an-marrow (a bone marrow with abnormal and normal metaphases) can be treated safely. In patients with an aa-marrow (a bone marrow with abnormal metaphases only), the karyotype analysis is helpful. Those with MIKA (minor karyotypic abnormalities) can be treated with relative safety, but those with MAKA (major karyotypic abnormalities) will be killed by chemotherapy. MIKA is characterized by a simple translocation or nondisjunction while MAKA by multiple such events, karyotypic instability etc., the latter type being preferentially associated with EL (erythroleukemia). In the bone marrow of patients with MAKA, when no normal metaphases are detected among 25 or so cells examined, no normal hemopoietic stem cells are expected to be remaining to repopulate the marrow after abnormal ones have responded to chemotherapy.