title: Low rather than high Ki-67 protein expression is an adverse prognostic factor in diffuse large B-cell lymphoma.
abstract: The prognostic role of overexpression of Ki-67 protein in diffuse large B-cell lymphoma (DLBCL) is still unclear. Furthermore, immunohistochemical studies have suggested a correlation between markers of proliferation, B-cell differentiation and apoptosis, but the prognostic relevance of these findings has not been clarified. To investigate the prognostic impact of Ki-67, in the context of this correlation, a retrospective immunohistochemical study was performed on 199 DLBCL patients treated with curative intent. Patients with low Ki-67 expression (<49%) had significantly worse progression-free (PFS) and overall (OS) survival, independent of clinical risk factors. In addition, low Ki-67 correlated to bcl-2 expression but not to non-germinal centre B-cell-like (non-GCB) phenotype. Each of these factors had negative impact on PFS and OS, but low Ki-67 expression also remained as an adverse prognostic factor independent of non-GCB phenotype and bcl-2 expression. Together, these results suggest that low rather than high Ki-67 protein expression is of prognostic importance in DLBCL.
authors.affiliation: Department of Internal Medicine, Section of Haematology and Coagulation, Göteborg, Sweden. sverker.hasselblom@vgregion.se
authors.forename: Sverker
authors.initials: S
authors.lastname: Hasselblom
authors.forename: Borje
authors.initials: B
authors.lastname: Ridell
authors.forename: Margret
authors.initials: M
authors.lastname: Sigurdardottir
authors.forename: Ulrika
authors.initials: U
authors.lastname: Hansson
authors.forename: Herman
authors.initials: H
authors.lastname: Nilsson-Ehle
authors.forename: Per-Ola
authors.initials: PO
authors.lastname: Andersson