The primary treatment for acute promyelocytic leukemia (APML) is?

The primary treatment for acute promyelocytic leukemia (APML) is all-trans retinoic acid (ATRA). ATRA plays a crucial role in the management of APML, as it targets the underlying cause of the disease related to the fusion gene created by the promyelocytic leukemia-retinoic acid receptor (PML-RARA) rearrangement.

By inducing differentiation of the abnormal promyelocytes into mature myeloid cells, ATRA not only improves the clinical outcomes but also reduces morbidity and mortality associated with this leukemia. When used in conjunction with chemotherapy, ATRA significantly increases the rates of complete remission and long-term survival in patients with APML.

While chemotherapy is a component of the overall treatment regimen, especially in combination with ATRA, it is the specific mechanism of ATRA in promoting differentiation that makes it the cornerstone of therapy for this particular type of leukemia. Bone marrow transplantation and immunotherapy are typically considered in different contexts or in cases of relapse or complications but are not the primary treatment modalities for newly diagnosed APML.