Abstract: PD47-04
Sources of Funding: American Institute for Cancer Research, NIH 1K24CA160653, GlaxoSmithKline

Introduction

Statin use is associated with lower risk of advanced prostate cancer, but mechanisms are not completely understood. In addition to cholesterol-lowering, statins also have systemic anti-inflammatory properties, but the effect of serum cholesterol levels and statin use on benign prostate inflammation has not been explored. The aim of this study was to examine associations between serum lipid levels, statin use, and histological prostate inflammation among men with a negative prostate biopsy.

Methods

We conducted a retrospective analysis of data from 6,655 men with a negative baseline prostate biopsy in the REduction by DUtasteride of prostate Cancer Events (REDUCE) trial. Statin use and serum lipid levels [total cholesterol, low and high density lipoprotein (LDL and HDL, respectively), triglycerides] were assessed at baseline. Prostate inflammation was classified as chronic (lymphocytes, macrophages) or acute (neutrophils) following central histological review of negative baseline prostate biopsies. Multinomial logistic regression was used to examine the effect of serum lipid levels and statin use on presence and extent of chronic and acute prostate inflammation [none, moderate (<20% biopsy cores), severe (≥20% biopsy cores)], adjusting for potential confounders.

Results

Chronic and acute prostate inflammation was found in 5,152 (77%) and 1,005 (15%) men, respectively. Serum lipid levels were not associated with presence or extent of chronic prostate inflammation. Total cholesterol, LDL and triglycerides were not associated with presence or extent of acute prostate inflammation. However, men with high HDL (≥60 vs. <40 mg/dl) had reduced presence of any acute inflammation (OR 0.79; 95% CI 0.63-0.99), and were less likely to have severe acute inflammation (OR 0.66; 95% CI 0.45-0.97). Statin users had reduced presence of any chronic prostate inflammation (OR 0.81; 95% CI 0.69-0.95), and were less likely to have severe chronic inflammation and severe acute inflammation (OR 0.80; 95% CI 0.68-0.95 and OR 0.73; 95% CI 0.53-1.00, respectively), relative to non-users.

Conclusions

In a cohort of men with a negative prostate biopsy, those with high HDL had lower presence and extent of acute prostate inflammation and statin users had reduced presence and extent of chronic inflammation. These findings support an effect of HDL and statin use on benign prostate inflammation. As we have shown inflammation is correlated with prostate cancer risk, this work suggests a mechanism linking serum lipid levels, statins and prostate cancer risk.

Funding

American Institute for Cancer Research, NIH 1K24CA160653, GlaxoSmithKline