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

Background The goal of our study was to find out whether the immunohistochemical expression of nuclear factor-kappa beta (NF-κB) p65 in biopsy samples with Gleason score 3 + 3 = 6 (GS 6) can be a negative predictive factor for Prostate cancer (PCa) indolence. Patients and methods Study was conducted on a retrospective cohort of 123 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 cytoplasmic and nuclear NF-κB p65 expression in biopsy cores with PCa were correlated with postoperative pathological stage, positive surgical margins, GS and biochemical progression of disease. Results After follow-up of 66 months, biochemical progression (PSA ≥ 0.2 ng/ml) occurred in 6 (5.1%) patients, 3 (50%) with GS 6 and 3 (50%) with GS 7 after radical prostatectomy. Both cytoplasmic and 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 frequent biochemical progression than those with negative cytoplasmic NF-kB reaction with PSA 0.2 ng/ml as cutoff point (p = 0.015) and a trend towards more biochemical progression with PSA ≥ 0.05 ng/ml as cutoff point (p = 0.068). Conclusions Cytoplasmic expression of NF-κB is associated with more biochemical progression 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.