Reviewer: Neha Vapiwala, MD
Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 23, 2007
Presenter: Lopez-Enriquez, A.
Presenter's Affiliation: University of Puerto Rico, Puerto Rico
Type of Session: Scientific
Acute Promyelocytic Leukemias (APL) are a unique entity in the field of carcinogenesis. They result from maturation arrest of cells at the promyelocyte stage, and are associated with a reciprocal chromosomal translocation of portions of chromosomes 15 and 17. This translocation leads to the formation of a fusion product between the PML gene and the alpha retinoic receptor site. The discovery that the compound all-trans-retinoic acid (ATRA) can induce maturation of the promyelocyte has significantly improved the ability to cure this disease. This current study was undertaken to assess the results of treatment using induction chemotherapy for tumor burden reduction, followed by differentiation and maturation of the promyelocytes with ATRA, for patients with APL.
Materials and Methods
Of 65 patients analyzed:
The authors report a very promising regimen of induction chemotherapy followed by ATRA for the treatment of APL. It is important to have an understanding of the criticality of timely diagnosis and treatment in this patient population. Also impressive was the marked effect of ATRA timing on outcome, with significant morbidity if given with induction chemotherapy, but significant improvement of efficacy if given at day 14. In fact, the authors cite reports from the U.S. of up to a 40% rate of ATRA syndrome when ATRA is used on day 1. Finally, the use of a non-standard consolidation regimen of daunorubicin alone resulted in a relapse rate of 60%, suggesting inadequacy of this therapy that is commonly used in some European centers. Ultimately, the future of APL treatment will hinge on continued optimization of combined modality approaches, adding into the armamentarium a variety of biologic agents including ATRA, arsenic trioxide, and kinase pathway inhibitors.