INV(16) MAY BE ONE OF THE ONLY FAVORABLE FACTORS IN ACUTE MYELOID-LEUKEMIA - A REPORT ON 19 CASES WITH PROLONGED FOLLOW-UP

We report our experience of treatment of acute myeloid leukemia (AML) with inv(ls). Nineteen of 531 (3.6%) cases of newly diagnosed AML karyotyped over a 12 year period had inv(16)(p13q22) and none had t(16;16) or del 16q. Morphologically, all patients had M(4eo). All patients were treated with conventional anthracycline-Ara-C chemotherapy, followed by moderate or more intensive consolidation chemotherapy. All patients received central nervous system (CNS) prophylaxis with intrathecal methotrexate and Ara-C, and cranial irradiation. Eighteen patients (95%) achieved complete remission (CR). Three had a bone marrow relapse, one had a CNS relapse and 14 patients remained in first CR, 11 of them with a follow-up greater than 44 months. Disease-free survival was 74% after 10 months, and actuarial survival 88% after 4 years, and 62% after 6 years. No other AML subgroup, in our experience, had a long-term survival approaching that of AML with inv(16) (although similar favorable outcome may be anticipated in acute promyelocytic leukemia treated by a combination of retinoic acid and chemotherapy).