A PROSPECTIVE EVALUATION OF THE ROLES OF ALLOGENEIC MARROW TRANSPLANTATION AND LOW-DOSE MONTHLY MAINTENANCE CHEMOTHERAPY IN THE TREATMENT OF ADULT ACUTE MYELOGENOUS LEUKEMIA (AML) - A SOUTHWEST-ONCOLOGY-GROUP STUDY

Between February 1982 and December 1986, the Southwest Oncology Group conducted a prospective study in patients with newly diagnosed acute m yeloid leukemia (AML) with two objectives: to evaluate the role of all ogeneic marrow transplantation for patients in first remission, and to evaluate the role of low-dose monthly maintenance therapy in those pa tients not transplanted in first remission. Among 522 evaluable patien ts, 295 (57%) achieved complete remission (CR), including 70% of patie nts age 49 or less. Twenty-four patients (15%) age 49 or less in CR we re not HLA-typed, mostly because of financial constraints. HLA-identic al donors were found for 39% of patients, of whom two-thirds were tran splanted in first CR. The 5-year disease-free survival among those tra nsplanted in first CR, those with donors not transplanted in first CR, and those less than age 50 without donors was 41, 42, and 29%, respec tively (P = 0.60). A total of 150 eligible patients were randomized to receive late intensification alone or late intensification plus month ly maintenance. In multivariate analyses, treatment with maintenance w as associated with prolonged disease-free survival (P = 0.028), but no t improved overall survival (P = 0.27). Factors associated with improv ed overall survival included younger age, lower white blood count (WBC ) at diagnosis, having leukemia of M3 morphology, and being of white r ace. In this study, a diagnosis of M3 AML was particularly favorable, with disease-free and overall survivals of 75 and 56%, respectively, a t 7 years.