| Abstract: |
Purpose: The nonrandom translocation t(1;19) has been associated with poor outcome in pediatric B-lineage acute lymphoblastic leukemia (ALL). Because most patients treated by contemporary therapies now achieve improved outcomes, we have reassessed the prognostic significance of t(1;19). Patients and: Cytogenetic data were accepted for 1,322 children (< 21 years old) with newly diagnosed ALL enrolled between 1988 and 1994 on risk-adjusted studies of the Children's Cancer Group (CCG). Forty-seven patients (3.6%) were t(1;19) positive ((+)); 1,275 (96.4%) were t(1;19) negative ((-)). Clinical characteristics and treatment outcome were compared using standard methods. Results: Translocation (1;19)(+) patients were more likely than t(1;19)(-) patients to be 10 years of age or greater (P < .001) or CD10(+)CD19(+)CD34(-) (P < .0001), or nonwhite (P = .02). patients with a balanced t(1;19) were less likely to be hyperdiploid than patients with an unbalanced der(19)t(1;19). Event-free survival (EFS) was similar for the overall group of t(1;19)(+) and t(1;19)(-) patients, with 4-year estimates of 69.5% (SD, 6.8%) and 74.8% (SD, 1.3%; P = .48), respectively. However, patients with unbalanced der(19)t(1;19) had significantly better outcomes than patients with balanced t(1;19): 4-year EFS were 80.6% (SD, 7.1%) and 41.7% (SD, 13.5%), respectively (P = .003). These differences were maintained within the individual studies analyses and after exclusion of t(1;19)(+) patients whose cells were hyperdiploid with more than 50 chromosomes. Conclusion: The overall group of t(1;19)(+) patients, as well as the subgroup with an unbalanced der(19)+ (1;19) had outcomes similar to that of t(1;19)(-) patients, whereas patients with balanced t(1;19) had poorer outcomes. Thus, although the overall prognostic significance of t(1;19) has been obviated by contemporary risk-adjusted protocols, the balanced t(1;19) translocation remains an adverse prognostic factor. (C) 1998 by American Society of Clinical Oncology. |
