[Effects of low dose Ara-C regimen in acute leukemias and RAEB]

Recent increase of leukemia among elderly patients prompted us to investigate the types of leukemia which can be induced into remission by low-dose Ara-C (LDAC) regimen. LDAC regimen was performed in 30 cases with overt acute leukemia (A), hypoplastic leukemia (B), and RAEB (C); Group A consists of M1 (1 case), M2 (4 cases), M3 (1 case), M4 (4 cases), M6 (1 case), and ALL (2 cases), Group B AML (8 cases), ALL (2 cases), and null (1 case), Group C RAEB (2 cases), and RAEB-T (4 cases). Complete remission (CR) rate was 23% (3/13) in group A, 64% (7/11) in group B, 0% (0/6) in group C. Partial remission rate was 33% (2/6) in group C. In group A, patients with M2 were induced into CR. In group B, both AML and ALL were induced into CR. Hypocellular marrow indicating low leukemic burden related to good sensitivity to Ara-C. Duration of CR was rather short; mean duration being 5.3 months. In group C, 2 PR cases of RAEB showed partial hematological recovery. LDAC regimen is effective especially for most of hypoplastic leukemia and some of M2. Side effects were tolerable, but all CR cases passed through bone marrow hypoplasia and needed supportive cares.