Andriole, Gerald L.

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 > 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.

Abstract Background: Unnecessary intervention and overtreatment of indolent disease are common challenges in clinical management of prostate cancer. Improved tools to distinguish lethal from indolent disease are critical. Methods: We performed a genome-wide survival analysis of cause-specific death in 24,023 prostate cancer patients (3,513 disease-specific deaths) from the PRACTICAL and BPC3 consortia. Top findings were assessed for replication in a Norwegian cohort (CONOR). Results: We observed no significant association between genetic variants and prostate cancer survival. Conclusions: Common genetic variants with large impact on prostate cancer survival were not observed in this study. Impact: Future studies should be designed for identification of rare variants with large effect sizes or common variants with small effect sizes. Cancer Epidemiol Biomarkers Prev; 24(11); 1796–800. ©2015 AACR.

Abstract Both anti- and proinflammatory effects of cigarette smoking have been described. As prostate inflammation is common, we hypothesized smoking could contribute to prostate inflammation. Thus, we evaluated the association of smoking status with acute and chronic inflammation within the prostate of men undergoing prostate biopsy. We retrospectively analyzed 8,190 men ages 50 to 75 years with PSA levels between 2.5 and 10 ng/mL enrolled in the Reduction by Dutasteride of Prostate Cancer Events study. Smoking status was self-defined as never, former, or current. Prostate inflammation was assessed by systematic central review blinded to smoking status. The association of smoking with inflammation in the baseline, 2-year, and 4-year biopsies was evaluated with univariable and multivariable logistic regressions. At study enrollment, 1,233 (15%), 3,203 (39%), and 3,754 (46%) men were current, former, and never smokers, respectively. Current smokers were significantly younger and had smaller prostates than former and never smokers (all P < 0.05). Former smokers were significantly heavier than current and never smokers (P < 0.001). Acute and chronic prostate inflammations were identified in 1,261 (15%) and 6,352 (78%) baseline biopsies, respectively. In univariable analysis, current smokers were more likely to have acute inflammation than former (OR, 1.35; P, 0.001) and never smokers (OR, 1.36; P, 0.001). The results were unchanged at 2- and 4-year biopsies. In contrast, current smoking was linked with chronic inflammation in the baseline biopsy, but not at 2- and 4-year biopsies. In conclusion, among men undergoing prostate biopsy, current smoking was independently associated with acute and possibly chronic prostate inflammations. Cancer Prev Res; 8(4); 312–7. ©2015 AACR.

Abstract Purpose: A recent meta-analysis showed that aspirin was associated with reduced prostate cancer risk. As anti-inflammatory medications lower PSA levels, whether these findings reflect reduced prostate cancer detection or lower prostate cancer risk is unknown. We tested the association between aspirin and nonaspirin NSAID use on prostate cancer diagnosis in REDUCE, where all men received biopsies at 2 and 4 years largely independent of PSA. REDUCE tested dutasteride for prostate cancer risk reduction in men with a PSA of 2.5 to 10.0 ng/mL and a negative prestudy biopsy. Experimental Design: We examined the association between aspirin, NSAIDs, or both and total, low-grade (Gleason < 7), or high-grade (Gleason ≥ 7) prostate cancer versus no prostate cancer using multinomial logistic regression among 6,390 men who underwent ≥1 on-study biopsy. Multivariable analyses were adjusted for age, race, geographic region, PSA, prostate volume, digital rectal examination, body mass index, treatment arm, smoking, alcohol, statins, hypertension, diabetes, and cardiovascular disease. Results: Overall, 3,169 men (50%) were nonusers, 1,368 (21%) used aspirin, 1,176 (18%) used NSAIDs, and 677 (11%) used both. In unadjusted models, aspirin was associated with reduced prostate cancer risk (OR = 0.85, P = 0.036). In multivariable analyses, aspirin was associated with reduced total prostate cancer risk (OR = 0.81, P = 0.015). Use of NSAIDs or NSAIDs and aspirin was not associated with total, low-grade, or high-grade prostate cancer, though all ORs were <1 (all P ≥ 0.08). Therefore, we created a dichotomous variable of aspirin and/or NSAID users versus nonusers. On multivariable analysis, the use of aspirin and/or NSAIDs was significantly associated with decreased total (OR = 0.87, P = 0.030) and high-grade (OR = 0.80, P = 0.040), but not with low-grade, prostate cancer risk (OR = 0.90, P = 0.15). Results were similar in placebo and dutasteride arms. Conclusions: Among men with a negative biopsy, aspirin and/or NSAID use was associated with decreased prostate cancer risk. Additional studies are warranted. Clin Cancer Res; 21(4); 756–62. ©2014 AACR.

Abstract Background: Studies suggest that obesity is associated with lower risk of prostate cancer but more aggressive cancers. As obesity lowers PSA levels, these observations may be influenced by detection bias. We examined the association between obesity and risk of low- and high-grade prostate cancer in REDUCE, in which biopsies were largely independent of PSA. Methods: The REDUCE study tested dutasteride for prostate cancer risk reduction in men with a PSA of 2.5 to 10.0 ng/mL and a negative biopsy. Study participants included 6,729 men who underwent at least one on-study biopsy. The association between baseline body mass index (BMI <25 kg/m2 normal weight; 25–29.9 kg/m2 overweight; and ≥30 kg/m2 obese) and risk of high-grade (Gleason ≥7) or low-grade prostate cancer (Gleason <7) versus no prostate cancer was examined using multinomial logistic regression. Results: Overall, 1,739 men (27%) were normal weight, 3,384 (53%) overweight, and 1,304 (20%) were obese. Obesity was associated with lower risk of low-grade prostate cancer in both univariable (OR, 0.74; P = 0.001) and multivariable analyses (OR, 0.79; P = 0.01). In univariable analysis, obesity was not associated with high-grade prostate cancer (OR, 1.08; P = 0.50). However, in multivariable analysis, obesity was associated with increased risk of high-grade prostate cancer (OR, 1.28; P = 0.042). This analysis was not able to address how obesity may influence prostate cancer progression. Conclusions: Obesity is associated with decreased risk of low-grade and increased risk of high-grade prostate cancer. These data provide further support to the hypothesis that obesity is associated with aggressive prostate cancer. Impact: Obesity is linked with aggressive prostate cancer. Avoiding obesity may prevent the risk of developing high-grade prostate cancer. Cancer Epidemiol Biomarkers Prev; 23(12); 2936–42. ©2014 AACR.