Clinico-biological features of 30 patients with acute promyelocytic leukemia and response to combination induction chemotherapy with all-trans retinoic acid and anthracycline.

30 adult patients with acute promyelocytic leukemia (APL) were seen at our institution overthe past 7 years. Their white cell count at presentation ranged from 400/microl to 54,900/microl. Cytogenetic studies were successful in 28 patients, of which 26(93%) were positive for t(15;17). Molecular analysis by reverse-transcription polymerase chain reaction demonstrated the PML-RARalpha fusion transcript in all 30 patients. The majority of patients had breakpoints at the 3' end with bcr1 products predominating. Complete remission rate of 92% was achieved using all-trans retinoic acid and anthracycline as induction chemotherapy in 26 patients. Of these, retinoic acid syndrome was observed in 4 cases, with 1 fatality. In conclusion, APL is a distinct entity with a highly specific molecular marker - t(15;17) translocation - that can be successfully induced into remission with all-trans retinoic acid and anthracycline in most patients.