Acute promyelocytic leukemia. New insights into diagnosis and therapy.

The clinical and laboratory features of APL are distinct. APL has been effectively treated with anthracyclines. Postremission therapy and the addition of other cytotoxic agents in induction may be beneficial. Early deaths remain a problem despite improved management of coagulopathy. The cytogenetic marker, t(15;17), reflects a molecular defect that splices two transcription factors, PML and RARA, to produce chimeric mRNA and proteins. RA, the natural ligand for RARA, is able to induce CR by stimulating differentiation and maturation of the malignant cells. The addition of RA to the therapeutic armamentarium of the hematologic oncologist will allow further refinement of the management of these patients. Diagnosis is unambiguous because the molecular defect can be readily detected. Our understanding of the biology downstream of the affected genes is incomplete. Other retinoids may be more effective than all-trans RA and may avoid the fall in plasma levels seen in patients chronically treated with RA. Combination of retinoids with other cytokines or cytotoxic agents may decrease the immediate mortality and improve long-term DFS in APL.