Patients with t(8;21)(q22;q22) and acute myeloid leukemia have superior failure-free and overall survival when repetitive cycles of high-dose cytarabine are administered

Purpose: To examine the effect of single compared with repetitive (at least three) cycles of high-dose cytarabine after induction therapy for patients with acute myeloid leukemia (AML) who have the t(8;21)(q22;q22) karyotype. Patients and Methods: Patients entered onto the study had AML and t(8;21) and attained a complete remission on four successive Cancer and Leukemia Group B studies. In these studies, either greater than or equal to three cycles of high-dose cytarabine or one cycle of high-dose cytarabine was administered, followed by sequential cyclophosphamide/etoposide and mitoxantrone/diaziquone with or without filgrastim support. Outcomes of these two groups of t(8;21) patients were compared. Results: A total of 50 patients with centrally reviewed AML and t(8;21) were assigned to receive one (n = 29) or greater than or equal to three cycles (9 = 21) of high-dose cytarabine as postinduction therapy. The clinical features of these two groups of patients were similar. Initial remission duration for t(8;21) patients assigned to one cycle of high-dose cytarabine was significantly inferior (P =.03), with 62% of patients experiencing relapse with a median failure-free survival of 10.5 months, compared with the group of patients who received greater than or equal to three cycles, in which only 19% experienced relapse and failure-free survival is estimated to be greater than 35 months. furthermore, overall survival was also significantly compromised (P =.04) in patients assigned to one cycle of high-dose cytarabine, with 59% having died as a consequence of AML, compared with 24% of those who received greater than or equal to three cycles of high-dose cytarabine. Conclusion: These data demonstrate that failure-free survival and overall survival of patients with t(8; 21)(q22;q22) may be compromised by treatment approaches that do not include sequential high-dose cytarabine therapy. J Clin Oncol 17:3767-3775. (C) 1999 by American Society of Clinical Oncology.