Cell cycle regulation score predicts relapse-free survival in non-germinal centre diffuse large B-cell lymphoma patients treated by means of immunochemotherapy.
OBJECTIVES
The cell cycle is under strict regulation by the retinoblastoma, p53 and p27 pathways, and the disruption of these pathways is an important characteristic of diffuse large B-cell lymphoma (DLBCL). In this study, we wanted to assess the function and prognostic significance of these pathways in DLBCL patients.


METHODS
Tissue samples from 120 DLBCL patients treated by means of R-CHOP-type chemotherapy were stained for the cell cycle-regulating proteins p16, p21, p27 and p53, and the germinal centre (GC) phenotype was determined according to Hans' algorithm. Based on the number of impaired cell cycle-regulating pathways a predictive score was obtained, covering three different prognostic groups: a 'favourable' group with damage in 0-1 of the studied pathways, a 'poor' group with damage in all three pathways and an 'intermediate' group comprising the rest of the patients.


RESULTS
The prognosis of non-GC DLBCL patients was significantly poorer vs. GC phenotype patients (P = 0.015). The prognostic score proved especially useful among non-GC phenotype patients, with 3-yrs relapse-free survival of 100% vs. 62.6% vs. 24.3% in the 'favourable-', 'intermediate-' and 'poor prognosis' groups, respectively (P = 0.003).


CONCLUSION
The prognosis of non-GC DLBCL patients is progressively impaired with the accumulation of damage in different cell cycle-regulating pathways.