Prostatic Inflammation Does Not Raise Prostate Cancer Risk
Histologic inflammation in prostate biopsy specimens is not associated with an elevated risk of subsequent prostate cancer (PCa), researchers concluded.
Tytti H. Yli-Hemminki, MD, of Tampere University Hospital in Tampere, Finland, and colleagues studied 293 prostate biopsy specimens obtained during the first screening round of a Finnish population-based randomized screening trial for PCa, which began in 1996. The biopsies were performed because of an abnormal PSA value (4 ng/mL or higher or 3-4 ng/mL and free to total PSA ratio of 0.16 or less) or a positive digital rectal examination. None of the biopsy specimens were suspicious for cancer.
The biopsy specimens were re-evaluated by a uropathologist to assess histologic inflammation—infiltration of the prostate by inflammatory cells. The researchers obtained results from subsequent screening rounds and obtained PCa diagnoses made outside the screening from the Finnish Cancer Registry. The median length of follow-up was 10.5 years.
During follow-up, 85 (29%) of the 293 men were diagnosed with PCa after the initial benign biopsy. Histologic inflammation was found in 66% of biopsy specimens. Subjects with inflammation at the initial biopsy had a slightly and non-significantly lower PCa risk in the second screening round relative to men who did not have inflammation (18% vs. 27%), the investigators reported in BJU International (2013;112:735-741). The risk was not appreciatively affected after adjusting for age, PSA, prostate volume, and family history of PCa, according to the researchers.
They concluded that inflammation in a prostate biopsy specimen is not a useful risk indicator in PCa screening.
The new findings are consistent with a previous study presented at the Canadian Urological Association's 2013 annual meeting. The study, by J. Curtis Nickel, MD, of Queen's University in Kingston, Ont., and colleagues demonstrated that acute or chronic prostatic inflammation each is independently associated with a significantly reduced risk of PCa. The researchers retrospectively analyzed data from 6,269 men who were in the REDUCE trial and who had a negative baseline cancer biopsy. They found a 25% lower risk of PCa within two years among men with acute inflammation found in the initial biopsy specimens and a 35% reduction in risk when chronic inflammation was present. The magnitude of the risk reduction was such that this information may be taken into consideration when planning further biopsies, Dr. Nickel said.