Long-term relapse-free survival in adult acute lymphoblastic leukemia

An intensive treatment program with curative intent was designed for adults with acute lymphoblastic leukemia (ALL). Forty-eight consecutive patients were treated with this protocol and 39 (81%) obtained a complete remission. Although the complete remission rate was high for patients with both null- and T-cell disease, those with null-cell leukemia had a significantly greater median duration of remission (> 306 weeks) than patients with T-cell disease (62 weeks). The median survival by life-table analysis for the 48 patients is projected to be > 310 weeks, and five patients have finished the 3-year treatment program and have been off therapy for 1-3 years without recurrence of disease. Classification of adult ALL by immune marker status is an important and easily done pretherapy maneuver that identifies subsets of patients with a significantly different prognosis when treated with the protocol described in this study. Those patients for whom leukemic cells had T-cell characteristics had a short median duration of remission. Most importantly, this treatment protocol identifies by therapeutic response a subset of adult patients with ALL whose leukemic blasts are characterized by the absence of immunological markers and who appear, in substantial proportion, to be potentially curable.