ACUTE MYELOID-LEUKEMIA IN MANITOBA - THE CONSEQUENCES OF STANDARD 7-INDUCTION THERAPY FOLLOWED BY HIGH-DOSE CYTARABINE POSTREMISSION CONSOLIDATION FOR MYELOSUPPRESSION, INFECTIOUS MORBIDITY, AND OUTCOME(3 REMISSION)

Background. To the authors' knowledge, the natural history of myelosup pression and infectious complications associated with the use of stand ard cytarabine (ARA-C) plus daunorubicin (''7 + 3'') remission-inducti on therapy for adult acute myeloid leukemia (AML) and high dose ARA-C (HDARA-C) consolidation has not been described completely. Methods. A retrospective study of untreated adult AML patients receiving standard 7 + 3 induction followed by ''5 + 2'' and HDARA-C consolidation was u ndertaken to describe the relationship of the myelosuppression profile s, blood product use, and infectious morbidity, and to correlate this finding with the outcome of antileukemic therapy. Multivariate techniq ues were used to evaluate variables of prognostic importance. Results. Fifty-nine percent of the patients achieved remission after a median of 35 days; almost half (48%) of these patients required more than one 7 + 3 induction course. For one, two, and three induction courses, th e mean number of days the patients experienced severe neutropenia (<0. 5 X 10(9)/l) were 22,5 +/- 10.9, 39.3 +/- 14.3, and 47.4 +/- 9.7 days (P < 0.001), respectively, and the infection rates were 1.45, 2.45, an d 3 infections per course (P < 0.0001), respectively. The pattern of b lood product use was similar. HDARA-C consolidation was the most signi ficant factor related to prolonged disease free survival, however the myelosuppression profiles and infection rates were surprisingly simila r to those for the single 7 + 3 induction courses. Conclusions. The 7 + 3 induction regimen used in this center provided only limited antile ukemic activity, while requiring multiple induction courses in a high proportion of patients. The use of multiple induction courses had cons equences of prolonged myelosuppression, increased blood product use, a nd incremental risks of infectious complications. HDARA-C consolidatio n for those who experienced complete remission appeared to improve dis ease free survival with myelosuppression comparable with that of patie nts who received primary induction therapy. The infection risk was acc eptable, with only a marginal increase in bacteremic and fungal infect ions.