Intensive combination chemotherapy (ROAP 10) and splenectomy in the management of chronic myelogenous leukemia.

To investigate the role of intensive chemotherapy in chronic myelogenous leukemia (CML), we treated 37 patients who had Philadelphia-positive benign-phase disease with rubidazone 300 mg/m2/d 1 (or daunorubicin 30 mg/m2/d X 4), cytosine arabinoside 80 mg/m2/d X 10, vincristine 2 mg/d 1, and prednisone 100 mg/d X 5 (ROAP 10), every four weeks for a median of three cycles. This treatment was followed by splenectomy and by subsequent maintenance therapy with 1 to 5 g hydroxyurea daily in intermittent courses. After a median follow-up of 42 months (range, 24 to 54 months), 20 patients (54%) remain in benign phase. The projected median survival is 52 months, and the three-year survival rate is 67%. Six patients (16%) developed blastic crisis, and eight died in the benign phase. A significant cytogenetic response, defined as a fall in the percentage of Philadelphia-positive cells to less than or equal to 30%, occurred in 18 (53%) of 34 patients who had serial cytogenetic studies. Six patients (18%) had reductions to 35% to 90%, whereas ten remained 100% positive. Cytogenetic response lasted for a median of six months from the time of maximal response (range, 1 to 18 months). Blastic crisis or accelerated disease developed in seven (44%) of the 16 patients who manifested minimal or no cytogenetic response, compared to only two of the 18 patients (11%) who achieved a significant cytogenetic response. Toxicity, which resulted in one death, was due to myelosuppression and consisted of febrile episodes during neutropenia (24% of courses), documented infections (8% of courses), and bleeding (8% of courses). ROAP 10 intensive therapy produces moderate survival improvement for CML patients compared to a matched historical control group of patients treated at our institution, but it has considerable myelosuppressive toxicity. The Philadelphia chromosome response is an important treatment-related prognostic factor.