Based on the prognostic factors obtained from our previous APL92 study, in the JALSG APL97 study, we intensified chemotherapy for patients with leukocyte counts > or = 3,000/microL and > or = 10,000/microL, also intensified consolidation chemotherapy, and then tested whether further chemotherapy is required in patients with negative RT-PCR for PML/RARalpha after the completion of consolidation therapy. Of 256 presently evaluable patients, 244 (95%) achieved CR. Predicted 5-year EFS is 67% and predicted 5-year overall survival 84%.