Double intensive consolidation chemotherapy in adult acute myeloid leukemia.

Abstract

Of 115 adult patients with de novo acute myeloid leukemia (AML), 87 (75.5%) achieved complete remission (CR) after induction treatment with zorubicin and conventional doses of cytarabine (Ara-C). Patients under age 45 years with histocompatibility locus antigen-identical sibling underwent bone marrow transplantation (BMT). The others were treated with two courses of intensive consolidation chemotherapy (ICC): course 1 with 4 days of high-dose Ara-C and 3 days of amsacrine (m-AMSA); course 2 with carmustine (BCNU), Ara-C, cyclophosphamide, and etoposide. Forty-two patients received both planned courses, 15 received only the first, and 13 patients could only support conventional maintenance therapy. Four patients died during consolidation. With a median follow-up of 60 months, the disease-free survival (DFS) after ICC at 5 years is 40.3% (+/- 6.5%), with no statistically significant difference between patients receiving one or two courses. The DFS for the 17 transplanted patients is comparable (P = .72) and is lower for the 13 excluded patients (23% +/- 11.5%, P = .046). Age did not influence the probability of remaining in CR. In univariate analysis, three parameters had a negative impact on the 5-year DFS: a high initial WBC count (52% for patients with less than 30 x 10(9) WBC/L v 12% for patients with greater than 30 x 10(9) WBC/L, P = .01), a long delay between induction treatment and course 1 (+/- 60 days; 63% v 29%, P = .01), and a long delay between course 1 and course 2 (+/- 60 days, 61.5% v 28.5%, P = .05). In multivariate analysis (Cox model), only the WBC count remained significant. This study confirms the value of intensive postremission chemotherapy, which can be compared in AML with allogeneic or autologous BMT. It also demonstrates the prognostic value of the initial WBC count. The optimal modalities of ICC remain to be defined by further studies.