Significant advancements have been achieved with regard to the outcomes of
acute promyelocytic leukemia (APL) patients through the introduction of
all-trans retinoic acid; however, early hemorrhagic death and differentiation syndrome remain the major causes of
remission induction failure in patients with APL. To investigate early death, serious
hemorrhage, and differentiation syndrome during
remission induction therapy in terms of incidence, risk factors, influence on outcomes, and prophylactic effects of several new
anticoagulants, the results of 344 patients enrolled in the
Acute Promyelocytic Leukemia 204 study conducted by the Japan Adult
Leukemia Study Group were analyzed. Early death was observed in 16 patients (4.7%), of whom 14 had serious
hemorrhage and 2 had differentiation syndrome. Serious
hemorrhage and differentiation syndrome of grade 2 or higher were observed in 21 and 54 patients, respectively. Patients who achieved complete remission had a 7-year disease-free survival of 84.8% if they did not experience serious
hemorrhage and 40.0% if they experienced serious
hemorrhage during
remission induction therapy (P = 0.001). Risk factor analyses showed that higher white blood cell count was associated with early death, higher white blood cell count and lower platelet count with serious
hemorrhage, and
leukocytosis during induction
therapy and higher body surface area with differentiation syndrome. In conclusion, these results indicate that patients with such high-risk features may benefit from more intensive supportive care. The hemorrhagic risk was not relieved by the introduction of new
anticoagulants. Further studies are required to establish the predictive impact of body surface area on differentiation syndrome. This trial is registered with UMIN-CTR as C000000154 on September 13, 2005.