Treatment of Promyelocytic Leukemia Tretinoin is an oral drug that induces the differentiation of leukemic cells bearing the t(15;17). APL is responsive to cytarabine and daunorubicin, but about 10% of patients treated with these drugs die from DIC induced by the release of granule components by dying tumor cells. Tretinoin does not produce DIC but produces another complication called the retinoic acid syndrome. Occurring within the first 3 weeks of treatment, it is characterized by fever, dyspnea, chest pain, pulmonary infiltrates, pleural and pericardial effusions, and hypoxia. The syndrome is related to adhesion of differentiated neoplastic cells to the pulmonary. | Chapter 104. Acute and Chronic Myeloid Leukemia Part 9 Treatment of Promyelocytic Leukemia Tretinoin is an oral drug that induces the differentiation of leukemic cells bearing the t 15 17 . APL is responsive to cytarabine and daunorubicin but about 10 of patients treated with these drugs die from DIC induced by the release of granule components by dying tumor cells. Tretinoin does not produce DIC but produces another complication called the retinoic acid syndrome. Occurring within the first 3 weeks of treatment it is characterized by fever dyspnea chest pain pulmonary infiltrates pleural and pericardial effusions and hypoxia. The syndrome is related to adhesion of differentiated neoplastic cells to the pulmonary vasculature endothelium. Glucocorticoids chemotherapy and or supportive measures can be effective for management of the retinoic acid syndrome. The mortality of this syndrome is about 10 . Tretinoin 45 mg m2 per day orally until remission is documented plus concurrent anthracycline chemotherapy appears to be among the safest and most effective treatments for APL. Unlike patients with other types of AML patients with this subtype benefit from maintenance therapy with either tretinoin or chemotherapy. Arsenic trioxide produces meaningful responses in up to 85 of patients refractory to tretinoin. The use of arsenic trioxide is being explored as part of initial treatment in clinical trials of APL. Additionally studies combining arsenic trioxide with tretinoin in the absence of chemotherapy are ongoing. The detection of minimal residual disease by RT-PCR amplification of the t 15 17 chimeric gene product appears to predict relapse. Disappearance of the signal is associated with long-term disease-free survival its persistence predicts relapse. With increases in the sensitivity of the assay some patients with persistent abnormal gene product have been found who do not suffer a relapse. Studies are underway to determine whether a critical threshold level of .
