The role of inflammation and infection in the pathogenesis of prostate carcinoma

Prostatitis and prostate carcinoma are both frequent entities of prostatic diseases. Epidemiological studies show significant associations between infection and inflammation and prostatic carcinoma. However, because of various confounding factors the results of these studies are inconclusive. Further findings are therefore needed to confirm the hypothesis that prostatic infection and inflammation might be a cause of prostatic carcinoma. We reviewed selected reports on the role of inflammation and infection in the pathogenesis of prostate carcinoma. Extensive genetic analyses show that several gene products, e.g. 2'-5'-oligoadenylate (2-5 A)-dependent Rnase, macrophage scavenger receptor 1 and Toll-like receptor-4, influence the susceptibility of prostate cells to infectious agents. Proliferative inflammatory atrophy (PIA) could be a connection between prostatitis and prostatic carcinoma. In the transition from PIA to prostatic intraepithelial neoplasia, the function of cellular detoxification is gradually lost by silencing of glutathione-S transferase, a detoxifying enzyme. This cellular feature leads to an increased susceptibility of the prostatic epithelial cells to genomic damage by inflammatory oxidants or nutritional carcinogens. Consecutive somatic genome damage might then arise which modulates the further pathogenesis of prostate carcinoma. Summarising these epidemiological, genetic and cell biological aspects, infectious prostatitis might have a causative role in the complex and multifactorial process of prostate carcinogenesis.