Abstract (Expand)
BACKGROUND: Histologically, follicular lymphoma (FL) grades 1, 2 and 3A are composed of two distinct cell types, centroblasts and centrocytes. FL grade 3B is composed only of centroblasts and has been … shown to differ in immunophenotype and genetics from FL that contain centrocytes. We aimed to understand the pathogenetic and clinical relation between FL grade 3A to FL grade 1/2 on the one hand and FL grade 3B on the other hand. PATIENTS AND METHODS: Trial patients with long-term follow-up and diagnosis of FL grade 3 were selected and samples underwent a second central pathological review using a multiple-observer approach to assess grading. RESULTS: Interobserver variability for diagnosing FL grade 3 was high. FL grade 3A frequently harbored areas of FL grade 1/2 within the same tissue specimen. FL grade 3B rarely coexisted with grade 1/2 or 3A, suggesting divergent pathogenesis. There was no statistically significant difference in outcome between 47 cases of FL grade 3A and 14 cases of grade 3B. Compared with grade 1/2 FL, both groups showed longer progression-free survival without late events, especially after immunochemotherapy; this outcome difference was retained after adjustment for clinical prognostic factors. The subgroup of FL grade 3A with an additional FL grade 1/2 component or a translocation t(14;18) showed a poorer outcome. In contrast, the FL grade 3A lacking t(14;18) and of localized stage resembled the pediatric type of FL and showed a very good outcome. FL3 with MYC breaks showed a poor outcome. CONCLUSIONS: The results suggest that first-line immunochemotherapy might allow long-lasting remissions in a subgroup of FL grade 3A similar to diffuse large B-cell lymphoma. Within FL3A, prognostic subgroups can be identified by analyzing for coexisting FL1/2 and MYC breaks.
Authors: K. Koch, E. Hoster, M. Ziepert, M. Unterhalt, G. Ott, A. Rosenwald, M. L. Hansmann, W. Bernd, H. Stein, V. Poschel, M. Dreyling, L. Trumper, M. Loffler, N. Schmitz, W. Hiddemann, M. Pfreundschuh, W. Klapper
Date Published: 28th Apr 2016
Publication Type: Not specified
Human Diseases: follicular lymphoma
PubMed ID: 27117536
Citation: Ann Oncol. 2016 Jul;27(7):1323-9. doi: 10.1093/annonc/mdw185. Epub 2016 Apr 26.
