Login to Access Video or Poster Abstract: MP20-06
Sources of Funding: none

Introduction

Although prostate atrophy (PA) is a common histological finding in prostate biopsy specimens its clinical significance remains unclear. Recent data suggests that PA in a prostate biopsy negative for prostate cancer (PCa) confers a decreased risk of subsequent PCa detection. However, the extent of PA varies from patient to patient. Therefore, we sought to evaluate whether baseline PA extent is associated with PCa incidence at 2-year repeat prostate biopsy in a clinical trial with systematic biopsies.

Methods

We performed a retrospective analysis of 3,165 men 50-75 years-old with prostate-specific antigen (PSA) between 2.5-10ng/mL and a prior negative biopsy in the placebo arm of the Reduction by Dutasteride of PCa Events (REDUCE) trial who underwent a 2-year repeat biopsy after a negative baseline biopsy for PCa. PA extent was defined as the percentage of cores with atrophic changes. The association of baseline PA with positive 2-year biopsies was evaluated with logistic regression in uni- and multivariable analysis, controlling for baseline covariates.

Results

PA involving none, 1-25%, 26-50%, 51-75% and >75% of the baseline cores was observed in 966 (30.5%), 1189 (37.6%), 677 (21.4%), 209 (6.6%), 124 (3.9%) cases, respectively. More extensive PA was associated with older age, lower prostate-specific antigen, larger prostate volume and higher prevalence of acute and chronic inflammations (all P<0.05). Compared to subjects without PA, those with 1-25%, 26-50%, 51-75% and >75% core involvement had an odds-ratio for PCa of 0.65 (95%CI=0.52-0.81), 0.60 (95%CI=0.46-0.78), 0.56 (95%CI=0.37-0.86) and 0.35 (95%CI=0.19-0.67), respectively (Table). In multivariable analysis, the extent of PA was independently associated with lower PCa risk (P<0.001). More extensive PA was associated with lower incidence of both low- (Gleason 2-6) and high-grade (Gleason 7-10) PCa (both P<0.01).

Conclusions

In a cohort of men undergoing repeat prostate biopsy 2 year after a negative baseline biopsy for PCa, the extent of baseline PA is independently associated with lower PCa risk in a dose-dependent fashion.

Funding

none