A distribution picture was prepared on the basis of the correlation between
peroxidase activity and cell size in leukemic cells using an automated leukocyte differential counter (Hemalog-D). From this,
acute nonlymphocytic leukemia was classified into three groups in which the therapeutic response was examined. The leukemic cells of Group I were medium or large and were negative or weakly positive to
peroxidase. These cells were characterized by their location in the upper part of the normal lymphocyte distribution. The leukocyte differential count, measured by a computer on the basis of the distribution picture, showed an increase in large unstained cells (LUC) and lymphocytes. The leukemic cells of Group II were large and positive to
peroxidase and were characterized by their location in the right upper part, across the region of LUC, monocytes, basophil and neutrophil leukocytes as seen in the distribution picture. The findings of Hemalog-D showed an increase in LUC, remainder and neutrophil leukocytes. The leukemic cells of Group III were medium-sized and moderately or strongly positive to
peroxidase. This group was characterized by their location in the lower part of normal neutrophil leukocytes and Hemalog-D showed an increase in neutrophil leukocytes. A total of 71 patients with
acute nonlymphocytic leukemia were assessed according to this classification. Group I (14 patients): 11 with
acute myelogenous leukemia (AML), 2 with
acute monocytic leukemia (AMoL) and 1 with
acute myelomonocytic leukemia ( AMMoL ); Group II (17 patients): 7 with AML and 10 with AMoL; Group III (40 patients): 28 with AML, 4 with AMoL, 1 with AMMoL and 7 with
acute promyelocytic leukemia (APL). These groups were treated with the protocol (
DCMP two step, BH-AC DMP, BH-AC
AMP) established by the Yamada
Leukemia Study Group of the Japan Welfare Ministry
Cancer Research Project (chairman Yamada, K). The complete remission rate was 35.7% in Group I, 58.8% in Group II and 85.0% in Group III. The difference between Groups I and III was statistically significant (P less than 0.005), as was the difference between Groups II and III (P less than 0.1), while that between Groups I and II was not significant. The median survival was 12 months in Group I, 9 months in Group II and 15 months in the Group III and the difference between Groups I and III was statistically significant (P less than 0.05). Group III included a small number of AMoL and APL patients in addition to AML, while Groups I and II consisted mainly of patients with AMoL and AML.(ABSTRACT TRUNCATED AT 400 WORDS)