Treatment of Acute Promyelocytic Leukemia (APL) by a Combination of All-Trans Retinoic Acid (ATRA) and Chemotherapy / 대한혈액학회지

ABSTRACT

BACKGROUND: All-trans-retinoic acid (ATRA) induces complete remission (CR) in the great majority of patients with PML/RAR -positive acute promyelocytic leukemia (APL). However, it is associated with a rapid rise in leukocytes in one third to half the patients, with potentially fatal "ATRA syndrome". Furthermore, most of the patients relapse with maintenance therapy using ATRA alone or low-dose chemotherapy. In this study, we have analyzed the outcome for APL patients who were treated with ATRA alone or combined with low-dose chemotherapy followed by postremission chemotherapy in Chonnam University Hospital from April 1993 to December 1997. METHODS: Sixteen patients with newly diagnosed APL were eligible to analysis. Patients received 45mg/m2 ATRA until CR occurred. If initial WBC were above 5,000/microliter, low-dose chemotherapy was concomitantly given, and if during the ATRA therapy WBC were above 5,000/microliter by day 5 or 10,000/microliter by day 10, or 15,000/microliter by day 15, low-dose chemotherapy was added. Four polychemotherapy cycles or allogeneic bone marrow transplantation were given as postremission therapy. RESULTS: Median age was 34 years (range, 17 to 67). Of 16 APL patients, 15 (93.8%) achieved CR and 1 (6.2%) died of intracerebral hemorrhage. After a median follow-up of 11.5 months (range, 0 to 47), the Kaplan-Meier estimated overall survival (OS) rate was 87.1 +/- 8.6% at 3 year, the event-free survival (EFS) rate was 87.1 +/- 8.6%, 58.0 +/- 24.4% and 29.0 +/- 23.9% at 1 year, 2 year and 3 year, and the disease-free survival (DFS) rate was 92.9 +/- 6.9%, 69.6 +/- 20.7% and 46.4 +/- 23.5% at 1 year, 2 year and 3 year, respectively. CONCLUSION: The present study suggests that ATRA with or without low-dose chemotherapy followed by postremission chemotherapy is a well-tolerated and effective regimen that is shown to improve the CR rate, reduce a early mortality rate and considerably prolong the overall survival in patients with newly diagnosed APL.