ACUTE PROMYELOCYTIC LEUKEMIA (APL) IN PATIENTS AGED > 70 Years.

Abstract 4160

Acute Promyelocytic Leukemia (APL) is a rare subtype of Acute Myeloid Leukemia (AML) more common in younger adults, with a median age of 45 – 50 years at onset. The use of All-trans Retinoic Acid (ATRA) as tailored treatment has made APL a very curable disease also in patients aged > 60 years; however, there are only few case reports in very elderly APL patients. To address this issue, we revised clinical data and treatment results in 12 patients aged > 70 years with newly diagnosed APL followed at our Institution from 1/91 to 12/2008. Clinical characteristics at onset were as follows: M/F 7/5, median age 74.7 years (range 70.0 – 80.8), M3/M3v 11/1, median WBC 1.3 × 10⁹/l (range 1.0 – 7.4), median PLTS 53 × 10⁹/l (range 12 – 302), BCR1/BCR3 6/6. According to Sanz risk score, 7 patients were at low-risk and 5 at intermediate-risk; 6/12 patients had arterial hypertension, 4/12 a concomitant cardiologic disease, 3/12 a cerebro-vascular disease and 2/12 a previous neoplasia. Induction therapy consisted of ATRA + Idarubicin in 8 patients (2/8 with reduced Idarubicin dosage) and ATRA alone in 4 patients; in this latter group, however, 2/4 needed to add chemotherapy (CHT) based on Mitoxantrone + AraC due to hyperleukocytosis during ATRA treatment. All patients achieved both morphological and molecular Complete Remission (CR) after a median time of 50 (range 29 – 65) and 105 (range 51 – 239) days, respectively. Infective complications were observed in 10/12 patients (4 episodes of FUO, 6 sepsis, 2 cystitis and 1 oral abscess) while ATRA syndrome occurred in 2/12 patients; in addition, there were 3 episodes of cardiac ischemia and 3 episodes of paroxystic atrial fibrillation. All but one patient received consolidation therapy (based on CHT alone in 7 patients, CHT + ATRA in 3 patients and ATRA alone in 1 patient), followed by maintenance treatment in 8 patients. Four patients had a relapse (hematological in 3 cases and molecular in 1 case) after 8, 11, 35 and 56 months respectively. At present, 6 patients are still alive, 4 died due to disease progression (3) or senectus while in CR (1) and 2 were lost to follow-up while in CR: mean event-free survival and overall survival were 89.2 months (95%CI 52.6 – 125.8) and 99.9 months (95%CI 65.0 – 134.7), respectively. In conclusion, ATRA-based treatment of APL is safe and effective also in very elderly patients, with long-lasting disease-free and overall survival.