IMPROVED RESULTS OF AN INTENSIFIED THERAPY IN ADULT ACUTE LYMPHOCYTIC-LEUKEMIA

Two consecutive studies for adult patients with acute lymphoblastic leukemia without previous treatment were analyzed and compared. Protocol ALL-79 included 137 patients treated with a 'standard therapy' consisting of prednisone, vincristine and daunomycin as induction, CNS prophylaxis with IT chemotherapy and maintenance with 6-mercaptopurine, methotrexate and pulses with vincristine and prednisone. Protocol ALL-82 included 145 patients treated with an 'intensive therapy' consisting of 8 weeks of induction with vincristine, prednisone, daunomycin and L-asparaginase, followed by 6-mercaptopurine, cyclophosphamide and cytosine arabinoside. At 3 months after induction, a 6-week consolidation therapy was given, with vincristine, adriamycin, dexamethasone and L-asparaginase, followed by cyclophosphamide, cytosine arabinoside and 6-mercaptopurine. Rates of complete remission were 80% and 78% for protocols ALL-79 and ALL-82 respectively. The probability of remaining in complete remission at 80 months was 20% and 34%, respectively (p = 0.0014). Median survival for protocol ALL-79 was 14 months, and 34 months for protocol ALL-82; at 80 months the probability of survival is 22% and 35% for the two protocols (P = 0.0024). In protocol ALL-82, the probability of remaining in CR for favorable prognosis patients (age = < 35 years and WBC = < 50.000) is 56% at 80 months, and only 8% at 50 months for the unfavorable group (age > 35 and/or WBC > 50.000) (P = 0.0012). The probability of survival was statistically superior in patients with favorable prognoses, with 54% of them still alive at 60 months compared to only 13% of patients with unfavorable prognoses (P = 0.0085). Only the outcomes of patients with favorable prognoses have significantly improved with the 'intensive therapy' employed in protocol ALL-82. In patients with unfavorable prognoses, new treatment modalities, such as bone marrow transplantation, should be explored.