The Role of ATRA Followed by Chemotherapy in the Treatment of Acute Promyelocytic Leukemia

There are different treatment protocols available for acute promyelocytic leukemia (APL) such as all-trans retinoic acid (ATRA) plus chemotherapy or arsenic trioxide (ATO) based regimens. In this study, we focused on the role of ATRA followed by an anthracycline-containing chemotherapy regimen. This study reported the outcome of APL patients at 501 army hospital; Tehran, Iran. Seventy-three patients were included between 1995 and 2015. Treatment in our center for the majority of cases included induction with ATRA followed by Cytarabine (AraC) and an anthracycline agent (daunorubicin), and then three cycles of consolidation chemotherapy. Maintenance consisted of a 2-year period of medication with ATRA, Methotrexate (MTX) and 6-mercaptopurine (6-MP). Relapsed cases were treated with ATRA and a combination of etoposide, mitoxantrone, and cytarabine. Kaplan-Meier estimate was used to calculate survival rates. We detected 5- and 10-year overall and disease-free survival rates of 51.6% and 50.2% respectively. For those patients who survived induction deaths and received ATRA-based chemotherapy the 5-year OS and DFS rates were 68.8% and 66.5%, respectively. Hematologic complete remission (CR) was observed in all but three patients, and relapse occurred in 12 cases. The cardinal causes of induction death were disseminated intravascular coagulation (DIC) and infection. Up to the end of the follow-up time, 31 patients died including 11 cases of the relapsed disease. The combination of ATRA and chemotherapy could lead to an acceptable CR rate and relapse incidences in newly diagnosed APL patients, but more effective strategies need to be developed for screening and treatment of relapse.