Chronic Periglandular Inflammation on Prostate Needle Biopsy Does Not Increase the Likelihood of Cancer on Subsequent Biopsy

Purpose: Recent literature suggests a role for chronic inflammation in the development of prostate cancer. We investigated the association of chronic periglandular inflammation on prostate needle biopsy with subsequent prostate cancer development and clinical disease features at presentation. Methods: Six hundred fifty-five patients were abstracted from a prostate /needle biopsy registry from Brigham and Women's Hospital presenting with prostate-specific antigen (PSA) > 4 ng/mL or abnormal digital rectal examination (DRE) between the years 1990 and 2004. DRE, PSA, PSA density, prostate volume, histology, and age were analyzed to identify clinical and pathologic associations with inflammation. Chronic inflammation was defined as an inflammatory cell infiltrate composed predominately of lymphocytes in a periglandular distribution. A subset of patients (n = 308) with follow-up biopsy results were used to identify if prostate inflammation predicted development of prostate cancer. Results: Modeling performed based on 4 biopsy samples revealed prostate volume (P < .001) and DRE (P = .02) as significant predictors of inflammation; DRE lost significance in models accounting for volume. Kaplan-Meier analysis demonstrated inflammation does not predict subsequent prostate cancer (P = .2). Cox models with the same endpoint show inflammation at initial biopsy (P = .3), inflammation at last biopsy (P = .4), and inflammation on any previous biopsy (P = .08) are not associated with time-to-positive biopsy. Conclusions: Although inflammation on initial and subsequent biopsy does not predict prostate cancer in this cohort, we cannot dismiss its role in prostate cancer pathogenesis. Addditional research is necessary to explore the relationship between prostate inflammation and prostate cancer development.