Comparing Induction and Consolidation with or without Cytarabine In the Treatment of Acute Promyelocytic Leukaemia In Hong Kong Chinese

Abstract

4366 Previous studies suggested that cytarabine was not required in the treatment of newly diagnosed acute promyelocytic leukaemia (APL). They suggested that omitting cytarabine in the treatment of APL could reduce treatment toxicity without increasing relapses and affecting survival. No previous study assessed the effect of cytarabine in the treatment of Chinese APL patients. We compared the outcome of APL patients with or without cytarabine in induction and consolidation therapy in Hong Kong Chinese in a local hospital. Method It was a retrospective study of newly diagnosed APL patients from Jan 1996 to Dec 2009. They were divided into two groups. One group was given ATRA (All-trans-retinoic acid) 45mg/m2/day combined with daunorubicin 60mg/m2/day for 3 days plus cytarabine 200mg/m2/day for 7 days as induction therapy. It was followed by two courses of consolidation with daunorubicin and cytarabine and then 2-year maintenance with low dose chemotherapy and intermittent ATRA. Another group was given the same treatment without cytarabine. The remission rate, relapse rate, overall survival and event-free survival were compared in the two groups of patients. Results Eighteen patients with median age of 41 (range 24–62) received cytarabine. 22% of them had initial WBC count >10,000/uL. Eight patients with median age of 42 (range 16–57) received no cytarabine. 25% of them had WBC count >10,000/uL. The complete remission rates were 100% in both groups. The two-year relapse rate was 5.5% (1/18) for cytarabine group and 62% (5/8) for no cytarabine group (p=0.004, Fisher's exact test). The two-year event-free survival was 82% for cytarabine group and 37% for no cytarabine group (p=0.0017). The two-year overall survival was 89% for cytarabine group and 75% for no cytarabine group (p=0.18). The adverse effects profile was similar in both groups. Conclusion The results support a role of cytarabine in addition to ATRA and daunorubicin in the treatment of newly diagnosed APL. The relapse rate was much lower in patients receiving cytarabine. The two-year event-free survival and two-year overall survival were also significantly better in the cytarabine group. Disclosures: No relevant conflicts of interest to declare.