Citations

75 Background: We have previously shown that chronic baseline prostate inflammation in an otherwise benign biopsy was associated with lower risk of prostate cancer in repeat prostate biopsies and lower tumor volumes for those who are diagnosed with cancer. In the present study, we evaluated whether baseline acute or chronic prostate inflammation among men with initial negative biopsies for prostate cancer was associated with cancer grade at the 2-year repeat prostate biopsy. Methods: Retrospective analysis of 889 men 50-75 years-old with negative baseline prostate biopsy and positive 2-year repeat biopsy for prostate cancer in the REDUCE study. Acute and chronic prostate inflammation (coded as present or absent) and cancer grade were determined by central pathology. The association of inflammation in baseline biopsies with 2-year repeat biopsy cancer grade (low-grade: Gleason scores 2-6 vs. high-grade: Gleason scores 7-10) was evaluated with t test, chi-squared test and logistic regression controlling for age, race, body-mass index (BMI), digital rectal exam (DRE), prostate volume, baseline pre-study PSA and treatment (dutasteride or placebo). Results: Chronic, acute inflammation and both were detected in 533 (60%), 12 (1%) and 85 (10%) baseline biopsies, respectively. Presence of acute and chronic inflammations were significantly associated with each other (P < 0.001). Patients with chronic inflammation had significantly larger prostates (P < 0.001). Both types of inflammation were unrelated to race, BMI, PSA or DRE. At 2-year biopsy, a total of 621 (70%) tumors were low-grade and 268 (30%) tumors were high-grade. In both uni- and multivariable analyses, men with baseline chronic inflammation had significantly less high-grade tumors (univariable OR = 0.64, 95% CI = 0.47-0.87, P = 0.004; multivariable OR = 0.68, 95% CI = 0.50-0.93, P = 0.016) than those without baseline chronic inflammation. Baseline acute inflammation was not associated with tumor grade. Conclusions: Among men undergoing repeat prostate biopsy 2 years after a negative baseline biopsy who all had cancer on the follow-up biopsy, the presence baseline chronic inflammation was associated with lower prostate cancer grade.

6 Background: Study compliance is crucial when the study outcome is determined by an invasive procedure, such as prostate biopsy. To investigate predictors of compliance in study-mandated prostate biopsies, we analyzed demographic, clinical and reported lifestyle data from the REDUCE trial. Methods: We retrospectively identified 8,062 men from REDUCE with at least 2-years of follow-up, and used multivariable logistic regression to test the association between baseline demographic and clinical characteristics and undergoing the study-mandated prostate biopsy at 2 years. We then examined whether missing any of these data was associated with undergoing a biopsy. Results: In REDUCE, 20% of men did not undergo a 2-year biopsy.On multivariable analysis, non-North American region was predictive of 35-55% increased likelihood of undergoing a 2-year biopsy (p ≤ 0.001). Being enrolled at a center that enrolled >10 subjects (2nd and 3rd tertile) was associated with a 40-49% increased likelihood of undergoing a 2-year biopsy (p < 0.001). Missing one or more baseline variables was associated with a 25% decreased likelihood of undergoing a 2-year biopsy (OR = 0.75; p = 0.002). Conclusions: In REDUCE, men outside North America, those at higher volume centers, and those with complete baseline data were more likely to undergo study mandated 2-year biopsies. Given prostate biopsy is becoming increasingly utilized as an endpoint in trials that are often multi-national, regional differences in compliance should be considered when designing future trials. Likewise, efforts are needed to ensure compliance in low-volume centers or among subjects missing baseline data.

122 Background: We have previously shown baseline prostate atrophy (PA) was independently associated with lower prostate cancer (PC) risk. Beyond PC risk, for those who develop PC it is unclear whether PA is associated with smaller, less aggressive and/or less advanced tumors. Thus, we evaluated whether baseline PA and PA severity in men with initial negative biopsy for PC was associated with PC volume at the 2-year repeat prostate biopsy. Methods: Retrospective analysis of 763 men 50-75 years-old with negative baseline prostate biopsy and positive 2-year repeat biopsy for PC with complete data in the REDUCE study. Presence and severity of PA, and tumor volume were determined by central pathology. The association of PA at baseline biopsies with 2-year repeat biopsy cancer volume variables was evaluated with linear and Poisson regressions and controlling for age, race, body-mass index (BMI), digital rectal exam (DRE), prostate volume, baseline and pre-repeat biopsy prostate-specific antigen (PSA) and treatment arm. Results: PA was detected in 458 (60%) baseline biopsies and was considered mild in 398 (87%) and moderate in 60 (13%) cases. Patients with PA had significantly larger prostates and lower baseline and pre-repeat biopsy PSA (P < 0.01). PA was unrelated to race, BMI, DRE or treatment arm. At 2-year biopsy, men with baseline PA had significantly lower overall mean total tumor volume (2.04µL vs 3.02µL; P = 0.006), mean number of biopsy cores involved (1.79 vs 2.11; P = 0.001), mean percent of cores involved (17.9% vs 21.2%; P = 0.001), average core involvement (0.20µL vs 0.30µL; P = 0.001) and overall mean percent tumor involvement (1.64% vs 2.35%; P = 0.006) than those without PA. The results were virtually unchanged in multivariable analysis (all P < 0.05 except for overall percent tumor involvement where P = 0.061). In the analysis of PA severity, a biological gradient was observed where moderate PA was associated with greater reduction in tumor volume compared to mild PA (data not shown). Conclusions: In a cohort of men with 2-year repeat prostate biopsy positive for PC after a negative baseline biopsy, baseline PA was associated with lower PC volume. These results suggest PA may be associated with less aggressive PC.

116 Background: Prostateinflammation is linked with prostate cancer. However, whether prostate inflammation varies by race is unclear. Methods: We analyzed baseline acute and chronic prostate inflammation by race in REDUCE. REDUCE was a 4-year, multicenter, placebo-controlled study where all men received a single, negative prostate biopsy within 6 months prior to enrollment. Among 8,046 men who met the inclusion criteria, we included those with data on baseline biopsy prostate inflammation, acute/chronic or none, determined by central pathology. Logistic regression was used to compare prostate inflammation by race, and models were adjusted for demographic and clinical features. Results: Of the 8,046 men, 7,326 were white (91.1%), 184 (2.3%) black, 132 (1.6%) Asian, 323 (4.0%) Hispanic, and 81(1%) unknown. Seventy eight percent of men had chronic and 15% had acute prostate inflammation. Men with chronic inflammation were older (p<0.001), while men with acute inflammation were younger (p<0.001) compared to men with none prostate inflammation. Both acute and chronic inflammation was associated with lower PSA (all p≤0.0001), smaller prostate volume (all p≤0.0001) and geographic region (all p≤0.006). On crude analysis, compared to whites, Asian men were two times more likely to have acute prostate inflammation (OR=1.92, 95%CI: 1.29-2.85, p=0.001), whereas the associations with Hispanic and black race were not significant (all p≥0.39). However, on multivariable analysis, black men were 36% less likely to have acute prostate inflammation (OR=0.64, 95%CI: 0.41-0.99, p=0.04), whereas the likelihood of having acute prostate inflammation remained high in Asians (OR=1.85, 95%CI: 1.25-2.85, p=0.004). No associations by race were found with chronic prostate inflammation. Conclusions: Given that at the population level, black race is a high risk factor for PC and Asian men have lower risk of PC, these data indicate that the presence of acute inflammation in a negative prostate biopsy could be an indication of future PC risk. Further studies to confirm these findings are needed. Clinical trial information: NCT00056407.

ObjectiveTo determine if cholesterol is a risk factor for the development of lower urinary tract symptoms in asymptomatic men.MethodsA post‐hoc analysis of the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) study was carried out in 2323 men with baseline International Prostate Symptom Score <8 and not taking benign prostatic hyperplasia or cholesterol medications. Cox proportion models were used to test the association between cholesterol, high‐density lipoprotein, low‐density lipoprotein and the cholesterol : high‐density lipoprotein ratio with incident lower urinary tract symptoms, defined as first report of medical treatment, surgery or two reports of an International Prostate Symptom Score >14.ResultsA total of 253 men (10.9%) developed incident lower urinary tract symptoms. On crude analysis, higher high‐density lipoprotein was associated with a decreased lower urinary tract symptoms risk (hazard ratio 0.89, P = 0.024), whereas total cholesterol and low‐density lipoprotein showed no association. After multivariable adjustment, the association between high‐density lipoprotein and incident lower urinary tract symptoms remained significant (hazard ratio 0.89, P = 0.044), whereas no association was observed for low‐density lipoprotein (P = 0.611). There was a trend for higher cholesterol to be linked with higher lower urinary tract symptoms risk, though this was not statistically significant (hazard ratio 1.04, P = 0.054). A higher cholesterol : high‐density lipoprotein ratio was associated with increased lower urinary tract symptoms risk on crude (hazard ratio 1.11, P = 0.016) and adjusted models (hazard ratio 1.12, P = 0.012).ConclusionsAmong asymptomatic men participating in the REDUCE study, higher cholesterol was associated with increased incident lower urinary tract symptoms risk, though the association was not significant. A higher cholesterol : high‐density lipoprotein ratio was associated with increased incident lower urinary tract symptoms, whereas higher high‐density lipoprotein was protective. These findings suggest dyslipidemia might play a role in lower urinary tract symptoms progression.

Abstract The role of metformin in prostate cancer chemoprevention remains unclear. REDUCE, which followed biopsy-negative men with protocol-dictated PSA-independent biopsies at 2- and 4-years, provides an opportunity to evaluate the link between metformin use and prostate cancer diagnosis with minimal confounding from screening biases. In diabetic men from REDUCE, we tested the association between metformin use, use of other antidiabetic medications, versus no antidiabetic medication use, and prostate cancer diagnosis as well as prostate cancer grade (low-grade Gleason 4–6 and high-grade Gleason 7–10) using logistic regression. Of the 540 diabetic men with complete data, 205 (38%) did not report use of any antidiabetic medications, 141 (26%) reported use of at least one antidiabetic medication other than metformin, and 194 (36%) reported use of metformin. During the 4-year study, 122 men (23%) were diagnosed with prostate cancer. After adjusting for various clinical and demographic characteristics, we found that metformin use was not significantly associated with total (OR, 1.19; P = 0.50), low- (OR, 1.01; P = 0.96), or high-grade (OR, 1.83; P = 0.19) prostate cancer diagnosis. Likewise, there was no significant association between the use of non-metformin antidiabetic medications and prostate cancer risk in both crude (OR, 1.02; P = 0.95) and multivariable analysis (OR, 0.85; P = 0.56). Furthermore, the interactions between antidiabetic medication use and BMI, geographic location, coronary artery disease, smoking, and treatment group were not significant (all P &gt; 0.05). Among diabetic men with a negative prestudy biopsy who all underwent biopsies largely independent of PSA, metformin use was not associated with reduced risk of prostate cancer diagnosis. Cancer Prev Res; 8(11); 1055–60. ©2015 AACR.