Minimal Disseminated Disease in High-Risk Burkitt's Lymphoma Identifies Patients With Different Prognosis

Purpose To study minimal disseminated disease (MDD) in children with Burkitt’s lymphoma (BL) and to determine its impact on prognosis. Patients and Methods We established a simplified long-distance polymerase chain reaction (LD-PCR) assay that can amplify up to 15 to 20 Kb of DNA sequence, making it possible to detect the t(8;14) at the genomic level with sensitivity of 104. We prospectively studied diagnostic biopsies and bone marrow aspirates from 134 patients affected by BL. Results A specific LD-PCR product was detected in 96 (72%) of 134 BL biopsies. Among 84 patients with t(8;14) positivity on tumor biopsy and bone marrow (BM), 26 (31%) had LD-PCR–positive BM, and 15 (18%) were positive at standard morphologic analysis. Twenty (85%) of 26 MDD-positive patients belonged to the R4 risk group, according to Berlin-Frankfurt-Munster definition. The 3-year progressionfree survival was 68% (SE, 10%) in MDD-positive patients in R4 compared with 93% (SE, 5%) in MDD-negative patients in R4 (P .03). By multivariate analysis (including MDD, sex, lactate dehydrogenase, CNS involvement), only MDD was predictive of higher risk of failure (hazard ratio, 4.7; P .04). Conclusion MDD identifies a poor-prognosis subgroup among children with high-risk BL. To improve disease control in these patients, a more effective risk-adapted therapy, possibly including anti-CD20 monoclonal antibody, should be considered.