The impact of obesity on the predictive accuracy of PSA in men undergoing prostate biopsy

Purpose: Obese men have been reported to have lower serum PSA values relative to normal-weight men in population-based studies, screening cohorts, and in men with prostate cancer (CaP) treated with surgery. There are concerns that PSA may be less accurate in detecting prostate cancer in men with increased body mass index (BMI). We determine whether the diagnostic potential of PSA is negatively influenced by obesity by comparing its operating characteristics across BMI categories among men undergoing prostate biopsy. Methods: Demographic, clinical, and histopathological data on 917 men who underwent trans-rectal ultrasound-guided prostate needle biopsy from 2002 to 2010 at a University hospital in Italy were used in the study. Men were categorized for BMI as follows: <25 kg/m 2 (normal weight), 25-29.9 kg/m 2 (overweight), and ≥30 kg/m 2 (obese). Receiver operator characteristics (ROC) curves were used to assess PSA accuracy for predicting prostate cancer overall and then stratified according to digital rectal examination (DRE) findings using the area under the ROC curve (AUC). Results: The obesity rate of the study cohort was 21 %. There was no statistically significant difference in the overall AUCs of PSA for predicting CaP among normal-weight (AUC = 0.56), overweight (AUC = 0.60), and obese men (AUC = 0.60; p = 0.68) in either DRE-positive or negative men. Conclusions: In a cohort of Italian men undergoing prostate biopsy, the performance accuracy of PSA as a predictor of CaP is not significantly altered by BMI. Obesity does not negatively impact the overall ability of PSA to discriminate between CaP and benign conditions. © 2012 Springer-Verlag

Greater Percent-free Testosterone Is Associated With High-grade Prostate Cancer in Men Undergoing Prostate Biopsy

OBJECTIVE To analyze the serum androgen concentrations in men who underwent an initial prostate biopsy, focusing on the percent-free testosterone (%FT) as a predictor of low- and high-grade prostate cancer (PCa). Most studies have suggested that the absolute serum testosterone and free testosterone levels are not related to PCa risk. However, to date, the concurrent effect of free and total testosterone levels has not been evaluated. In particular, the association of the %FT (free testosterone/total testosterone) with PCa risk has not been explored. METHODS From 2006 to 2010, we collected data on 812 white Italian men with no history of PCa who underwent 12-core biopsy. The testosterone, free testosterone, and %FT (free testosterone/total testosterone) were examined as predictors of low- grade (Gleason score of = 7) PCa using crude and adjusted multinomial logistic regression analysis. RESULTS On multivariate analysis, testosterone (P >= .11) and free testosterone (P >= .45) were not significantly associated with low- or high-grade PCa. A greater %FT level significantly predicted high-grade PCa on both crude (P = .01) and multivariate (P = .02) analysis but not low- grade PCa (P >= .38). When examined in tertiles, men in the greatest %FT tertile had a significant twofold increased risk of high-grade PCa (odds ratio 2.04, 95% confidence interval 1.23-3.37, P = .005). CONCLUSION In white Italian men, a greater %FT level was associated with an increased risk of high-grade PCa on initial prostate biopsy. These findings suggest that a high %FT level, rather than the absolute androgen levels, might be associated with high-grade PCa. Additional studies are needed to confirm our findings. UROLOGY 80: 162-168, 2012. (c) 2012 Elsevier Inc. All rights reserved

High serum folate is associated with reduced biochemical recurrence after radical prostatectomy: Results from the SEARCH Database

Introduction To analyze the association between serum levels of folate and risk of biochemical recurrence after radical prostatectomy among men from the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Materials and Methods Retrospective analysis of 135 subjects from the SEARCH database treated between 1991-2009 with available preoperative serum folate levels. Patients' characteristics at the time of the surgery were analyzed with ranksum and linear regression. Uni- and multivariable analyses of folate levels (log-transformed) and time to biochemical recurrence were performed with Cox proportional hazards. Results The median preoperative folate level was 11.6ng/mL (reference = 1.5-20.0ng/mL). Folate levels were significantly lower among African-American men than Caucasians (P = 0.003). In univariable analysis, higher folate levels were associated with more recent year of surgery (P < 0.001) and lower preoperative PSA (P = 0.003). In univariable analysis, there was a trend towards lower risk of biochemical recurrence among men with high folate levels (HR = 0.61, 95%CI = 0.37-1.03, P = 0.064). After adjustments for patients characteristics' and pre- and post-operative clinical and pathological findings, higher serum levels of folate were independently associated with lower risk for biochemical recurrence (HR = 0.42, 95%CI = 0.20-0.89, P = 0.023). Conclusion In a cohort of men undergoing radical prostatectomy at several VAs across the country, higher serum folate levels were associated with lower PSA and lower risk for biochemical failure. While the source of the folate in the serum in this study is unknown (i.e. diet vs. supplement), these findings, if confirmed, suggest a potential role of folic acid supplementation or increased consumption of folate rich foods to reduce the risk of recurrence