Pattern of extramedullary relapse in latin patients with acute promyelocytic leukemia (APL) treated with all-trans-retinoic acid (ATRA) and chemotherapy

Abstract

17520 Background: Extramedullary relapse (EMR) is a rare event in APL and reports have suggested a possible rol of ATRA in its pathogenesis. Our study intent to determine the pattern of EMR in Latin patients treated whit trans-retinoic acid (ATRA) and chemotherapy (CT). Methods: We evaluated 87 patients diagnosed of APL from January 2001 to December 2005. They were treated with ATRA and chemotherapy. Results: 74/87 received ATRA plus chemotherapy. Median age was 28 (5–68). 39/74 (53%) patients were female. Subtype M3v constituted 21/74 (28%). 76% presented disseminated intravascular coagulation (DIC). Extramedullary deposit was observed in 7 cases, more frequent was central nervous system (CNS). According the Sanz Index, 32/74 (32%) were High Risk, 40/74 (54%) Intermediate Risk, 2 Low Risk. 31/55 (56%) presented t(15,17). 52/74 (70%) patients had complete response. EMR was documented in 8 (15%) (CNS: 5, External Auditory Foramen: 3), 4 were High Risk. Median time to EMR was 11.5 months (7.03–27.3). 55% are alive at date. The following median was 36 months, 41 months of Disease Free Survival (DFS), rate was 62 % to 3 years. Overall survival was 44 months; rate was 83% to 3 years. Conclusions: EMR incidence was 8%, higher report that other series, this event was presented in CNS and external auditory foramen. It suggest to establish EMR risk factors and to include CNS prophylactic treatment. No significant financial relationships to disclose.