Aims: To evaluate the different expression patterns and the prognostic significance of cell cycle regulatory molecules in diffuse large B-cell lymphomas (DLBCLs) of germinal centre (GC) and non-GC phenotypes.
Methods and results: Tissue microarray slides composed of 126 extranodal and 88 nodal DLBCLs were immunostained for p16, p21, p27, p14 and p53. DLBCLs were classified into GC and non-GC phenotype according to the immunohistochemical expression of bcl-6, CD10, and MUM1. Aberrant expression of p53 was more frequent in the GC phenotype in nodal cases (P = 0.038), and the loss of p16, p21 and p14 expression was significantly more common in the non-GC phenotype (P = 0.004, P = 0.001, P < 0.001). Concurrent disruptions of the p16-Rb and p14-p53 pathways as represented by the immunoprofile of p16/p14/p53 (-/-/+) were associated with a poor prognosis in the GC phenotype [mean survival 31 months in the p16/p14/p53 (-/-/+) group versus 62 months in the other groups, P =0.0485].
Conclusions: The expression and prognostic implications of cell cycle regulatory molecules differ between GC and non-GC phenotypes in DLBCLs. The immunoprofile of p16/p14/p53 (-/-/+) within the GC phenotype of DLBCLs can be defined as a poor prognostic subgroup.