Login to Access Video or Poster Abstract: MP33-14
Sources of Funding: None.

Introduction

Chronic inflammation is a well-known contributor to several human cancers. The aim of this study was to investigate the role of chronic prostatic inflammation in prostatic carcinogenesis, with a specific focus on high grade cancers.

Methods

A retrospective search was performed to identify prostate biopsy cases accessioned in our institution between 01/01/2007 and 12/31/2009. Pathology reports of each case were reviewed. We reviewed the slides of all patients with benign initial prostate biopsies, followed by at least one set of prostate biopsies longer than one year after the initial biopsies. The presence and extent of chronic inflammation and other pathological findings were assessed and recorded. We defined chronic inflammation as involvement of 1% or more of the surface area of the prostatic tissue by a chronic inflammatory cell infiltrate. We also recorded the presence or absence of postatrophic hyperplasia (PAH) and inflamed atrophy (IA), a lesion defined by the presence of clusters of atrophic glands surrounded by a prominent and readily identifiable lymphocytic infiltrate. Cases in which prostatic adenocarcinoma was subsequently diagnosed were evaluated for Gleason pattern and score.

Results

Among 1006 patients who underwent prostate biopsies, a total of 244 cases with available slides were diagnosed initially as benign prostatic tissue, of which two patient subsets were identified, including 206 patients with and 38 patients without chronic inflammation in the initial biopsy. Post-atrophic hyperplasia (PAH) and inflamed atrophy (IA) were more frequently identified in patients with chronic inflammation. In follow up biopsies performed at least 1 year following the initial benign biopsies, 75 patients (36%) with chronic inflammation were found to have adenocarcinoma, whereas cancer was found in only 6 patients (16%) without chronic inflammation in the initial biopsies. Of those who were found to have cancer after the initial biopsies showing only chronic inflammation, 46% had a Gleason 3 + 3 pattern (grade group 1), 20% had a Gleason 3 + 4 pattern (grade group 2), and 13% had a Gleason 4 + 3 pattern (grade group 3). Significantly, high grade cancers with Gleason score of 8 or higher (grade groups 4 or 5) were identified in 21% (16 of 75) of patients with chronic inflammation in the initial benign biopsies, whereas no patient without chronic inflammation in the initial benign biopsies were found to have cancer with a Gleason score of 8 or higher (grade groups 4 or 5).

Conclusions

Our retrospective follow up study suggests a strong association between chronic prostatic inflammation and the development of prostatic adenocarcinoma.

Funding

None.