Early application of arsenic trioxide improved the clinical outcomes of acute promyelocytic leukemia

Nowadays, acute promyelocytic leukemia (APL) is the most potentially curable leukemia. Recent studies indicate all-trans retinoic acid (ATRA) plus arsenic trioxide (ATO) would be an alternative to ATRA plus chemotherapy (CT) for low-to-intermediate-risk APL. This study investigated whether early application of ATO was beneficial for the long-term outcomes of APL. We applied two induction therapies, consisted of ATRA combined with low-dose CT and ATRA plus ATO followed by the same consolidation and maintenance treatments. A total of 132 newly diagnosed low-to-intermediate-risk APL patients were included and retrospectively investigated. The ATO group achieved an earlier and durable molecular complete remission with the median time of 90 days compared with the low-dose CT group (112 days, P=0.02), while the liver toxicity was higher in the ATO group (20% vs. 4.2%, P=0.01). The 3-year relapse rate was significant lower in ATO group (1.8% vs. 12.1%, P=0.02). The 3-year event-free survival in ATO and low-dose CT group were 93.1% and 80.3%, respectively (P=0.03). In conclusion, early application of ATO in induction therapy of APL attained quick and sustained molecular remission, which reduced the relapse rate and may benefit the long-term outcomes.