Long-term survey of outcome in acute promyelocytic leukemia

Objective To investigate all-trans retinoic acid (ATRA) and As2O3 which wer e found to be able to selectively induce differentiation and apoptosis in a cute promyelocytic leukemia (APL) and recently became standard treatment fo r de novo or relapsed APL. The results of long-term follow up in 72 APL pat ients were presented and prognostic factors discussed. Methods Seventy-two newly-diagnosed patients with APL entering CR with ATRA were consolidated with chemotherapy alone (31 patients), ATRA + chemothera py (30 patients) and ATRA alone (11 patients). Univariate analysis was done to identify the potential prognostic factors. A total of 40 cases of patie nts relapsed after their first complete remission, including 3 groups of pa tients: group A, patients treated with ATRA and chemotherapy after relapse (8 patients); group B patients treated with As2O3 alone for 2(nd) CR and co nsolidation (21 patients); group C patients treated with As2O3 for 2(nd) CR and both As2O3 and chemotherapy for consolidation (11 patients). Univariat e analysis was also done to identify the potential prognostic factors. Results With a median follow-up of 45 months (5-75 months), the median even t-free survival was 21 months and median overall survival was not achieved. The estimated 3- and 5-year event-free survival (EFS) and over-all surviva l (OS) were 32.5 +/- 10.5%, 18.4 +/- 7.5% and 73.8 +/- 17.5%, 58.5 +/- 15.2 %. In denovo patients, the combination of ATRA and chemotherapy in both ind uction and post-remission treatment was found to be statistically significa nt for EFS (P = 0.023), and initial peripheral leukocyte count was signific antly related to OS. In relapsed patients, only the treatment of As2O3 with or without chemotherapy in consolidation after relapse was statistically s ignificant for CR and both EFS (P = 0.0061) and OS (P = 0.0013). Conclusion ATRA is an effective induction therapy and can be considered as first choice of treatment in denovo APL, Addition of chemotherapy in both i nduction and post-remission therapy can delay or decrease the possibility o f relapse compared to ATRA alone. As2O3 is an effective agent for relapsed APL and remains an important prognostic factor for relapsed APL.