Objectives: To investigate associations of chronic inflammatory infiltrate (CII) with prostate cancer (PCa) risk and the number of positive cores in patients elected to a first set of biopsies.
Materials and methods: Excluding criteria were as follows: active surveillance, prostate specific antigen (PSA) ≥ 30 ng/l, re-biopsies, incidental PCa, less than 14 cores, metastases, or 5-alpha reductase inhibitors. The cohort study was classified as negative (control group) and positive cores between 1 and 2 or > 2.
Results: The cohort included 421 cases who did not meet the exclusion criteria. PCa was detected in 192 cases (45.6%) of which the number of positive cores was between 1 and 2 in 77 (40.1%) cases. The median PSA was 6.05 ng/ml (range 0.3-29 ng/ml). Linear regression models showed that CII was an independent predictor inversely associated with the risk of PCa. Multinomial logistic regression models showed that CII was an independent factor that was inversely associated with PCa risk in cases with positive cores between 1 and 2 (OR = 0.338; p = 0.004) or more than 2 (OR = 0.076; p < 0.0001) when compared to the control group.
Conclusion: In a cohort of men undergoing the first biopsy set after prostate assessment, the presence of CII in the biopsy core was an independent factor inversely associated with PCa risk as well as with the number of positive biopsy cores (tumor extension). Clinically, the detection of CII in negative biopsy cores might reduce the risk of PCa in repeat biopsies as well as the probability of detecting multiple positive cores.
Keywords: Chronic inflammation; Prostate biopsy; Prostate cancer; Prostate volume; Prostate-specific antigen.