Prospective use of RT-PCR for PML/RARa might be used to guide a total tehrapy approach in APL, including refined diagnosis, front-line treatment, assessment of response and anticipated salvage therapy for patients who undergo molecular relapse.

Inclusion Criteria:

• Age >= 1 years and < 61 years
• Morphologic diagnosis of APL
• PS <= 3
• Presence in leukemic cells at diagnosis of t(15;17), and/or PML/RARa rearrangement by RT-PCR. T
• The presence of additional cytogenetic lesions is not considered an exclusion criterion
• Serum creatinine <=2.5 mg/dL
• Serum bilirubin, alkaline phosphatase, or GOT/ASAT <= 3 times the upper normal limit
• Negative pregnancy test
• Written informed consent

Exclusion Criteria:

• Age >= 61 years
• Prior antileukemic chemotherapy for APL
• Absence of PML-RARa rearrangement after successful RNA extraction and amplification of control gene
• Prior antileikemic chemotherapy for APL
• Presence of a concomitant malignant neoplasm, except basal cell carcinoma Concurrent treatment with cytotoxic chemotherapy or radiotherapy
• Oteher progressive malignant disease. However, secondary acute promyelocytic leukemia following "cured" Hodgkin's disease or otehr cured malignancies may be included, as well as secondary leukemias following other exposure to alkylating agents or radiation for other reasons