Morphological diagnoses of the Japan Adult Leukemia Study Group acute myeloid leukemia protocols: Central review

A morphological review system of the Japan Adult Leukemia Study Group has d eveloped from the AML-87 through the AML-92 experience. We reviewed 1427 (9 0%) of 1592 cases enrolled in the AML-87, -89, or -92 protocols for morphol ogy; 1408 (88%) were eligible. The rate of diagnostic concordance between e ach institute and the Committer on Morphological Diagnosis ranged from 76% to 80%. Acute myeloid leukemia (AML) subtypes were as follows: AML M0, 27 ( 2%); M1, 179 (13%); M2, 472 (34%); M3, 358 (25%); M4, 265 (19%); M5,57 (4%) ; M6, 39 (3%); and M7, 11 (1%). The reason for the high number of patients with AML M3 is that many M3 patients were enrolled in the AML-92 protocol, which contained all-trans-retinoic acid. AML MO, M6 and M7 belonged to the poor prognostic groups Auer bodies were found in 284 (53 %) of 538 patients who survived significantly longer than those without Auer bodies in AML-87 /-89. In AML-92 except for AML M3, 259 (43%) of 602 cases were Auer(+) and also showed better survival rates. The survival of patients with less than or equal to 50% myeloperoxidase (MPO)positive blast cells was better than t hose with less than or equal to 50% MPO+ blast cells in AML-87/-89. This tr end was also seen in AML-92 excluding M3. AML with trilineage dysplasia (AM L/TLD) is characterized as a subtype of de novo AML that shows morphologica l dysplasia of mature hematopoietic cells on a background of leukemic blast cells The number of patients with AML/TLD was 89 (16.5%) of 545 patients r eviewed in AML-87/-89. AML-92, except for M3, showed a higher rate of patie nts with TLD (161 cases; 27.6%) because there were no patients with TLD in the AML M3 group. Survival rates for AML/TLD were worse than those for AML/ non-TLD in both the AML-87/-89 and -92 protocols. Eighty percent of all cas es (793/986) entered in AML-92 were analyzed cytogenetically. Fifty-one cas es were not available for karyotyping because of a lack of mitoses or inapp ropriate preparations. The most frequent karyotype was normal, which accoun ted for 34.2%. The t(15;17), t(8;21), and inv(16) karyotypes, which are reg arded as good risk factors, were 23.8%, 9.2%, and 1.6%, respectively. Abnor mal chromosomes 5, 7, t(9;22), and t(6;9) were considered to be poor or int ermediate risk factors As a new system of karyotyping begins in the ongoing AML protocol, useful chromosomal data will be obtained in the near future. (C) 2001 The Japanese Society of Hematology.