c-FLIP does not correlate with response to immunochemotherapy treatment and outcome of patients with nodal diffuse large B-cell lymphoma

Abstract

Cellular FLICE-inhibitory protein (c-FLIP) is a critical anti-apoptotic regulator that inhibits apoptosis-inducing ligand, (TRAIL)-induced apoptosis as well as chemotherapy-triggered apoptosis in malignant cells. The present study was designed to investigate the clinical and prognostic significance of c-FLIP expression in patients with nodal diffuse large B-cell lymphoma (DLBCL) treated with immunochemotherapy.

Methods: We have analyzed lymph node biopsy specimens, obtained from 60 patients with newly diagnosed nodal DLBCL treated with immunochemotherapy (R-CHOP or R-EPOCH). The expression of c-FLIP was analyzed using the standard imunohistochemical method on formalin-fixed and routinely processed paraffin-embedded lymph node specimens and evaluated semi quantitavely as a percentage of tumor cells.

Results: c-FLIP immunoexpression (>50% positive tumor cells) has been found in 28 (46.7%) patients, and observed as cytoplasmic staining. There was not significant difference in c-FLIP immunoexpression between GCB and non-GCB subtype of DLBCL (P=0.639). Besides, c-FLIP immunoexpression had no significant association with IPI, "bulky" disease, extranodal localization, haemoglobin, Ki-67 immunoexpression or other clinico-pathological parameters. c-FLIP positivity has no significant influence on therapy response and survival in patients with DLBCL (P=0.562 and P=0.093, respectively). Patients with c-FLIP overexpression did not relapse more often that patients without expression of this apoptotic protein (P=0.365).

Conclusion: Our results suggest that c-FLIP immunoexpression can not be used as a prognostic factor in patients with nodal DLBCL treated with immunochemotherapy.