Therapy of Acute Lymphoblastic Leukemia in Adults (ALL)

Abstract

In the past decade substantial progress has been made in the treatment of adult ALL (acute lymphoblastic leukemia). With current intensive chemotherapy protocols 30-40% of patients can be cured. The further development of diagnostic facilities and retrospective analysis of outcome of patients have shown that ALL is not a homogenous disease. Diagnosis by morphological, immunological, cytogenetical, and molecular biological methods is a prerequisite for stratification in risk groups. These groups have a different clinical course and prognosis and require specific therapy approaches. Patients with T-<i>ALL</i> and/or mediastinal tumor with CR (complete remission) rates of 80-85% and long-term survival of 40-50% are now a facorable prognostic subgroup. Prognosis of B-<i>ALL</i> patients has been improved substantially by the use of specific therapy concepts. 50-60% of patients can be probably cured. The majority of ALL patients have B-precursor <i>ALL</i>, which can be stratified in high- and low-risk patients by the use of risk factors (time to CR, WBC, Philadelphia (Ph’) chromosome, and bcr-abl rearrangement). Therapy results in this group stagnated in the past years at CR rates of 75-85% and survival rates of about 30%. The main reason is the poor results in the subgroup of <i>Ph’/bcr-abl-positive</i><i>ALL</i> (20-25% of adult ALL patients) that could not be improved by conventional therapy approaches. Despite an increase in CR rates to 70% long-term survival is still between 10 and 15%. Elderly ALL patients with increased therapy-related toxi-city and mortality are also at high risk of relapse or death. The adult ALL Study Group (GMALL) is currently investigating the possibilities for further improvements by the use of risk-adapted therapy regimens, intensified chemotherapy and BMT in high-risk patients. Further progress might be made by the use of biologic response modifiers, growth factors, better supportive care, and the control of minimal residual disease and multidrug resistance.