Clinicopathological implications of nuclear factor κB signal pathway activation in diffuse large B-cell lymphoma.

Abstract

Although abnormal activation of the nuclear factor κB (NF-κB) signaling pathway plays an important role in the pathogenesis of diffuse large B-cell lymphoma (DLBCL), only a few studies have dealt with the relation of NF-κB activation to clinical outcomes in this disease. We analyzed the clinical characteristics of 147 consecutive DLBCL patients, examined paraffin-embedded tissues from 120 of them to identify the activation of the NF-κB pathway by using immunohistochemical staining, and performed an overall survival (OS) analysis. Expression of P-p65 and p52 was found in 30.0% (n = 36) and 35.8% (n = 43) of the patients, respectively. Coexpression of these factors was found in 16.7% (n = 14) of the cases. Patients were divided into 4 groups according to P-p65 and/or p52 expression: P-p65(+) only, p52(+) only, both P-p65(+) and p52(+), and both P-p65(-) and p52(-). The 3-year OS rates in the 4 groups were 51.3%, 68.3%, 34.6%, and 85.8%, respectively (P = .006). Univariate analysis showed that early stage (P = .032), low International Prognostic Index score (P = .001), less than 2 extranodal metastases (P = .014), complete remission with chemotherapy (P < .0001), germinal-center B-cell-like subtype (P = .049), Ki-67 < 75% (P = .017), and P-p65(-) (P = .002) or p52(-) (P = .031) were associated with longer 3-year OS. Multivariate analysis indicated that P-p65 expression was an independent prognostic factor for shorter OS (P = .032). In conclusion, NF-κB pathway activation markers P-p65 and p52 predict poor survival in DLBCL patients.