Non-Hodgkin's lymphomas of childhood: an analysis of the histology, staging, and response to treatment of 338 cases at a single institution.

Abstract

Between 1962 and 1986, a total of 338 consecutive newly diagnosed children and adolescents with non-Hodgkin's lymphomas (NHLs) were evaluated and treated at St Jude Children's Research Hospital (SJCRH). Median follow-up is 6.6 years (range, 1.8 to 23 years). The patients ranged in age from 7 months to 21 years (median, 10 years), and 71% were males. All cases were staged (I to IV) by a clinical staging system. Eighteen percent were stage I, 21% stage II, 43% stage III, and 18% stage IV. Cases frankly leukemic at diagnosis (ie, greater than 25% marrow blasts) were excluded from the analysis. Pathologic material from all cases was reviewed and classified according to the Working Formulation. The histologic distribution of cases was as follows: 38.8% diffuse small non-cleaved cell (undifferentiated, Burkitt's and non-Burkitt's); 26.3% diffuse large-cell, mainly immunoblastic; 28.1% lymphoblastic; and 6.8% other. Treatment policy evolved over time to a stage- and histology-specific strategy for treatment assignment, and overall results significantly improved by era from 37% (+/- 5%) 2-year event-free survival (EFS) for patients treated before 1975 to 77% (+/- 4%) since 1978. By univariate and multivariate Cox regression analyses, the era of treatment (hence, the protocol-specific treatment itself), the stage, and the log of the initial serum lactic dehydrogenase (LDH) emerged as the most powerful prognostic indicators, while histology per se was not significantly related to outcome. For the 154 patients treated since 1978, the 2-year EFS by stage was 97% (+/- 3%) for stage I, 86% (+/- 6%) for stage II, 73% (+/- 6%) for stage III, and 47% (+/- 11%) for stage IV (P less than .0001). Compared with our previous experience, we conclude that the cure rate of childhood NHL has doubled in the last decade with modern management.