Acute Promyelocytic Leukemia: Update on Risk Stratification and Treatment Practices

Acute promyelocytic leukemia (APL) is a rare but highly curable form of acute myeloid leukemia (AML) whose genetic hallmark is the balanced reciprocal translocation t(15;17)(q22;q12) which fuses the promyelocytic leukemia (PML) and retinoic acid receptor alpha (RARα) genes (Wang and Chen in Blood 111:2505-2515, 2008; Lallem and-Breitenbach et al. in J Exp Med 189:1043-1052, 1999). It is a rare disease and accounts for 5-10% of adult AML with an estimated incidence of 0.1/100,000 in Western countries (Sant et al. in Blood 116:3724-3734, 2010). In the United States, 600-800 new cases are diagnosed every year although the incidence appears increased in patients originating from Latin America (Douer in Best Pract Res Clin Haematol 16:357-367, 2003). Notably, the median age at diagnosis is approximately 40 years which is significantly lower than in AML where the median age is 68 years.