Significance of nuclear factor - kappa beta activation on prostate needle biopsy samples in the evaluation of Gleason score 6 prostatic carcinoma indolence

Abstract

Background. The goal of our study was to find out whether the immunohistochemical expression of NF-κB p65 in biopsy samples with Gleason score 3+3=6 (GS 6) can be a negative predictive factor for PCa indolence.

Patients and methods. Study was based on a retrospective cohort of 178 PCa patients with initial total PSA ≤ 10 ng/ml, number of needle biopsy specimens ≥8, GS 6 on biopsy and T1/T2 estimated clinical stage who underwent laparoscopic radical prostatectomy and whose archived formalin-fixed and paraffin-embedded (FFPE) prostate needle biopsy specimens were used for additional immunohistochemistry staining for detection of NF-κB p65. Both cytoplasmatic and nuclear NF-κB p65 expression in biopsy cores with PCa were correlated with postoperative pathological stage, positive surgical margins, GS and biochemical progression (BP) of disease.

Results. After follow-up of 66 months, BP (PSA ≥ 0,2 ng/ml) occurred in 6 (5,1%) patients, 3 (50%) with GS 6 after RP and 3 (50%) with GS 7. Cytoplasmatic nor nuclear NF-κB p65 expressions were not significantly associated with pathological stage, positive surgical margin and postoperative GS. Patients with positive cytoplasmic NF-kB reaction had significantly more BP compared to those with negative cytoplasmic NF-kB reaction with PSA 0,2 ng/ml as cutoff point (p=0,015) and a trend towards more BP with PSA ≥ 0,05 ng/ml as cutoff point (p=0,068).

Conclusions. Cytoplasmic expression of NF-κB is associated with more BP and might be an independent prognostic factor for recurrence-free survival (RFS), but further studies including larger patient cohorts are needed to confirm these initial results.