T-Cell Acute Lymphoblastic Leukemia in Children

Abstract

Newer chemotherapeutic and support programs have resulted in survival of approximately 40%–50% of children with acute lymphoblastic leukemia (ALL) (Sallan et al. 1980; George et al. 1979: Haghbin 1977). It is likely that children who fail conventional therapy programs represent subsets of patients whose disease is biologically distinct, and, as such, require different therapeutic strategies. Approximately 15%–20% of children with ALL have lymphoblasts with surface receptors for sheep erythrocytes or T-cell antigens. In a treatment program at our institution patients with T-cell disease had a median disease-free survival of 12 months compared to 47 months for those with non-T-cell disease (P= 0.0004) (Fig. 1) (Sallan et al. 1980). The majority of relapses in the T-cell population occurred at extramedullary sites, whereas nearly all of the non-T-cell patients relapsed in the bone marrow. When it became apparent that patients with T-cell disease enjoyed a less than 20% disease-free survival, a new treatment strategy was designed.