[1088] Chronic Inflammation on Initial Benign Prostate Biopsy Is a Negative Predictor of Subsequent Cancer Detection

Chen Zhao, Sriram Venigalla, Hiroshi Miyamoto. University of Rochester, Rochester, NY

Background: Experimental evidence suggests that inflammation promotes prostate carcinogenesis. However, the presence of prostatic inflammation may cause a persistent increase in prostate-specific antigen (PSA) levels in individuals with a negative prostate biopsy, prompting unnecessary subsequent biopsies.
Design: In a retrospective, blinded manner, we analyzed the initial prostate biopsies of 114 consecutive patients who received a diagnosis of either benign (n=80) or focal high-grade prostatic intraepithelial neoplasia (n=34) between January 2008 and April 2011 at our institution, and who underwent a subsequent prostate biopsy after an average of 18.5 months (range: 1-42 months). The total number of inflammatory cells, including lymphocytes and neutrophils, mainly identified in periglandular regions and/or the stroma, was counted from a single level of an entire biopsy.
Results: On subsequent biopsy, 29 (25%) patients were found to have prostate cancer while no carcinoma was identified in the remainder (75%) of cases. The number of lymphocytes per core was significantly increased in non-cancer (NCA) group (mean±SEM: 114.3±15.6), compared to adenocarcinoma (PCA) group (mean±SEM: 62.1±8.2) (P=0.004). It was noteworthy that no cancer was subsequently detected in 16 cases which averaged more than 157.5 lymphocytes per core. When the severity of lymphocytic infiltration was divided into 3 groups: 1) none/mild (<100/core); 2) moderate (100-200 /core); and 3) severe (>200/core), its difference between the NCA and PCA groups was still statistically significant (P=0.013). The density of lymphocytes (per cm2) was also greater (P=0.006) in NCA (mean±SEM: 890.4±124.0) than in PCA (mean±SEM: 494.0±65.1). Additionally, prostate volume (cc) determined by ultrasound was significantly greater in NCA group (mean±SEM: 55.6±3.0 vs. 43.5±2.9; P=0.042). In contrast, no significant differences (NCA vs. PCA; mean±SEM) in age distribution [62.9±1.0 vs. 63.0±1.5 (years); P=0.959], PSA level [6.5±1.0 vs. 6.4±0.8 (ng/mL); P=0.903], and neutrophil number [8.6±2.2 vs. 7.9±5.0 (per core); P=0.888] were observed between the two groups.
Conclusions: Increased chronic inflammation, but not increased acute inflammation, on initial benign prostate biopsies is likely to be a predictor of subsequent negative biopsies. Therefore, the inclusion of the presence, quality, and severity of chronic inflammation in pathology reports, along with other clinical parameters such as prostate volume, may strengthen subsequent non-cancer diagnoses, resulting in fewer unnecessary biopsies.
Category: Genitourinary (including renal tumors)

Monday, March 4, 2013 1:00 PM

Poster Session II # 152, Monday Afternoon


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