Several groups, especially the PETHEMA group (in their LPA96 and 99 trials), obtained low relapse rates in newly diagnosed Acute Promyelocytic Leukemia (APL) patients by combining ll-transretinoic acid (ATRA) and anthracyclines without Ara-C, suggesting that avoiding Ara-C in the chemotherapy of APL reduced treatment toxicity without increasing relapses. While the relapse rate for the children with white blood cell(WBC) counts greater than 10×109/L at presentation were higher than those WBC counts less than 10×109/L (31% and 3.5%,respectively) in the LPA96 and 99 trials. A recent adult randomized trial show that avoiding Ara-C leads to an increased risk of relapse in the APL patients with WBC counts less than 10×109/L. The role of the Ara-C remains controversial. And there are very limited data reported on children with APL so far.

Some studies suggest patients with high-risk disease should be treated with intensified doses of anthracycline, or intermediate/ high-dose Ara-C or As2O3 as an early consolidation, so as to decrease the risk of relapse.However, a higher cumulative dose of anthracycline may lead to cardiac toxicity, especially for children. In addition, containing Ara-C will led to more therapy-related toxicity. The benefit to add Ara-C to the schedules is questionable and remains a matter of investigation in children.

Inclusion Criteria:

• Acute Promyelocytic Leukemia (APL)

Exclusion Criteria:

• > 14

Between May 2010 and December 2016, 65 consecutive paediatric (≤14years old) patients who were genetically confirmed with a new diagnosis of APL were admitted in our hospital.The follow-up of the patients was updated on Jan 2017 and included a median of 32 months (range, 1 to 79). The adverse event data were collected from the patient enrolled in our trials.The median period of time were 32 months (range, 1 to 79).

All adverse events described were founded during the course of induction therapy.