RESUMO
OBJECTIVE: To investigate the clinical features and outcomes of high-risk acute promyelocytic leukemia (APL) patients. METHODS: A retrospective analysis was conducted to compare the clinical characteristics and prognosis of 118 high-risk APL patients (WBC≥10 × 10(9)/L) and 234 low and intermedia-risk patients (WBC <10×10(9)/L) from January 2003 to April 2015, who were treated in the First Affiliated Hospital of Zhejiang University and Yinzhou People's Hospital affiliated to Medical College of Ningbo University. RESULTS: The initial platelet counts of high-risk APL were significantly lower than that of low and intermediate-risk groups (P=0.003); the major type of PML-RARα isoforms in high-risk patients was short-form (51.8% vs 28.2%, P <0.001); the early death (ED) rate of high-risk patients was higher than low and intermedia-risk patients (20.3% vs 2.6%, P<0.001); in contrast, the complete remission (CR) rate and 5 years estimated overall survival (OS) rate of the former were lower than the latter (76.3% vs 94.9%, P <0.001; 74.2% vs 93.7%, P <0.001). However, the CR rate (P=0.682) and 5 years estimated OS rate (P=0.481) did not have difference when the ED patients were excluded. The 5 years estimated relapse-free survival (RFS) and central nervous system (CNS) relapse were 82.7%, 9.4%, respectively, which were lower than low and intermediate-risk groups (87.8%, 1.4% ) with statistic difference (P=0.048, 0.002). High-dose cytarabine and intrathecal chemotherapy may reduce the risk of CNS relapse. CONCLUSION: The outcomes of high-risk APL patients were worse than low and intermediate-risk group owing to the high ED rate and CNS relapse, it was important to decrease the ED rate and emphasis the CNS prophylaxis for high-risk APL patients.