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Background:To evaluate PSA levels and kinetic cutoffs to predict positive bone scans for men with non-metastatic castration-resistant prostate cancer (CRPC) from the Shared Equal Access Regional Cancer Hospital (SEARCH) cohort.Methods:Retrospective analysis of 531 bone scans of 312 clinically CRPC patients with no known metastases at baseline treated with a variety of primary treatment types in the SEARCH database. The association of patients' demographics, pathological features, PSA levels and kinetics with risk of a positive scan was tested using generalized estimating equations.Results:A total of 149 (28%) scans were positive. Positive scans were associated with younger age (odds ratio (OR)=0.98; P=0.014), higher Gleason scores (relative to Gleason 2-6, Gleason 3+4: OR=2.03, P=0.035; Gleason 4+3 and 8-10: OR=1.76, P=0.059), higher prescan PSA (OR=2.11; P<0.001), shorter prescan PSA doubling time (PSADT; OR=0.53; P<0.001), higher PSA velocity (OR=1.74; P<0.001) and more remote scan year (OR=0.92; P=0.004). Scan positivity was 6, 14, 29 and 57% for men with PSA<5, 5-14.9, 15-49.9 and ⩾50 ng ml−1, respectively (P-trend <0.001). Men with PSADT ⩾15, 9-14.9, 3-8.9 and <3 months had a scan positivity of 11, 22, 34 and 47%, correspondingly (P-trend <0.001). Tables were constructed using PSA and PSADT to predict the likelihood of a positive bone scan.Conclusions:PSA levels and kinetics were associated with positive bone scans. We developed tables to predict the risk of positive bone scans by PSA and PSADT. Combining PSA levels and kinetics may help select patients with CRPC for bone scans. [ABSTRACT FROM AUTHOR]

Background:To evaluate the factors associated with positive bone scans after biochemical recurrence (BCR) following radical prostatectomy in both hormone-naive subjects and subjects after androgen-deprivation therapy (ADT).Methods:Retrospective analysis of 380 bone scans of 301 hormone-naive subjects and 214 bone scans of 137 subjects after ADT following BCR from the Shared Equal Access Regional Cancer Hospital database. Generalized estimating equations and local regression plots were used to evaluate bone scan positivity by patients' demographics, pathological features, PSA levels and kinetics.Results:Among hormone-naive subjects and subjects on ADT, bone scan positivity was seen in 24 (6%) and 65 (30%) subjects, respectively. In hormone-naive subjects, the higher prescan PSA, higher PSA velocity (PSAV) and shorter PSA doubling time (PSADT) were significantly associated with positive scans (P=0.008, P<0.001 and P<0.001, respectively). In subjects after ADT, the prescan PSA, PSAV and PSADT were significantly associated with positive scans (P=0.011, P<0.001 and P=0.002, respectively). Regression plots showed increased scan positivity with increasing PSA levels and shortening PSADT (all P<0.001) for both hormone-naive subjects and subjects after ADT. For a given PSA level and PSADT, subjects on ADT had higher bone scan positivity.Conclusions:In both hormone-naive subjects and subjects after ADT, more aggressive and advanced disease identified by higher PSA levels, higher PSAV and shorter PSADT were associated with higher bone scan positivity. For the same PSA level and PSADT, subjects after ADT had higher bone scan positivity than hormone-naive subjects. Therefore, PSA levels and kinetics may be used as selection criteria for bone scan in these patients. [ABSTRACT FROM AUTHOR]

Background:Statins are associated with lower PSA levels. As PSA is the primary method for prostate cancer (PC) screening, this confounds any associations between statins and risk of being diagnosed with PC. Thus, we examined the association between statins and cancer and high-grade cancer in REDUCE, where biopsies were largely PSA-independent.Methods:Post-hoc secondary analysis of REDUCE, which was a prospective multinational randomized controlled trial of dutasteride vs placebo for 4 years among men aged 50-75 years with PSA of 2.5-10.0 ng ml−1 and a negative biopsy at baseline, and included PSA-independent biopsies mandated at 2- and 4-years. Analyses were limited to men who underwent at least one biopsy while under study (n=6729). The association between baseline statin use and risk of overall, high-grade (Gleason 7) or low-grade (Gleason 6) PC vs no cancer was examined using multinomial logistic regression adjusting for age, race, baseline PSA, prostate volume, rectal examination findings, body mass index (BMI), comorbidities, smoking, alcohol intake and treatment arm.Results:Of 6729 men who had at least one biopsy while on study, 1174 (17.5%) were taking a statin at baseline. Men taking statins were older, had lower PSA levels, higher BMI values and lower serum testosterone and dihydrotestosterone levels, though differences, were slight. Statin use was not associated with overall PC diagnosis (multivariable OR 1.05, 95% CI 0.89-1.24, P=0.54). When stratified by grade, statin use was not associated with low-grade (multivariable OR 1.03, 95% CI 0.85-1.25, P=0.75) or high-grade cancer (multivariable OR 1.11, 95% CI 0.85-1.45, P=0.46). The major limitation is the inclusion of only men with a negative baseline biopsy.Conclusions:Among men with a negative baseline biopsy and follow-up biopsies largely independent of PSA, statins were not associated with cancer or high-grade cancer. [ABSTRACT FROM AUTHOR]

Background:We examined the relationship between weight change in the year before radical prostatectomy (RP) and biochemical recurrence (BCR) and adverse pathology.Methods:We abstracted data from 359 men undergoing RP in the SEARCH (Shared Equal Access Regional Cancer Hospital) database between 2001-2007. Logistic regression and Cox proportional hazards models were used to test the association between weight change in the year before surgery and adverse pathology and BCR, respectively.Results:In all, 152 (42%) men gained weight, 193 (54%) lost weight and 14 (4%) had the same weight. Among weight gainers, median gain was 2.4 kg and among weight losers, median loss was 2.7 kg. As a continuous variable, weight change was not associated with adverse pathology or BCR (all P>0.05). In secondary analysis, on multivariate analysis, men gaining 2.5 kg were at higher BCR risk (hazards ratio=1.65, 95% confidence interval (CI): 1.03-2.64, P=0.04) while weight loss 2.5 kg was not associated with BCR (hazards ratio=0.83, 95% CI: 0.54-1.29, P=0.41).Conclusions:As a continuous variable, weight change was not associated with outcome. In secondary hypothesis-generating analyses, weight gain 2.5 kg in the year before surgery, regardless of final body mass index, was associated with increased BCR following RP. If validated, these data suggest weight gain 2.5 kg may promote prostate cancer progression. [ABSTRACT FROM AUTHOR]

Men with diabetes mellitus are less likely to be diagnosed with prostate cancer (PCa). As diabetic men have lower serum PSA, it is unclear if this is due to lower PCa incidence or reflects detection bias from fewer PSA-triggered biopsies. To account for differential biopsy rates, we used multivariate regression to examine the link between diabetes and PCa risk in the Reduction by Dutasteride of Prostate Cancer Events (REDUCE) trial, which required all subjects to undergo biopsy regardless of PSA. We further tested for interaction between diabetes and obesity. Diabetes status and body mass index (BMI) measurements were obtained at baseline. On multivariate analysis, diabetes was not associated with PCa risk (odds ratio (OR) 1.01, 95% confidence interval 0.79-1.30, P=0.92) or risk of low- or high-grade disease (all P0.65). When stratified by obesity, diabetes was also not associated with PCa risk in any BMI category (all P0.15). However, there was suggestion of effect modification by obesity for high-grade disease (P-interaction=0.053). Specifically, diabetes was associated with decreased risk of high-grade PCa in normal-weight men but increased risk in obese men (OR 0.35 vs 1.38). In the REDUCE trial, when all men underwent biopsy, diabetes was not associated with lower PCa risk, but rather equal risk of PCa, low-grade PCa and high-grade PCa. [ABSTRACT FROM AUTHOR]

The American Cancer Society's updated screening guidelines for prostate cancer (CaP) render digital rectal examination (DRE) optional. We investigated the impact of DRE on CaP detection among obese men. Data from 2794 men undergoing initial prostate biopsy at three centers were analyzed to assess CaP risk attributed to abnormal DRE across body mass index (BMI) categories. Predictive accuracies of a combination of PSA, age, race, center and biopsy year including or excluding DRE findings were compared by areas under the receiver-operating characteristics curves. In all cohorts, obese men were less likely to have abnormal DREs diagnosed than non-obese men. As BMI category increased, abnormal DREs became stronger predictors for overall CaP in individual (P-trends0.05) and combined (P-trend<0.001) cohorts, and for high-grade CaP in the Italian (P-trend=0.03) and combined (P-trend=0.03) cohorts. DRE inclusion improved the predictive accuracy for overall and high-grade CaP detection among all obese men (P0.032) but not normal-weight men (P0.198). DRE inclusion also near-significantly improved overall CaP detection in obese men with PSA<4 ng ml-1 (P=0.081). In conclusion, the predictive value of DRE is dependent on obesity and is significantly higher among obese men than normal-weight men. [ABSTRACT FROM AUTHOR]

A wide array of biomarkers is being investigated as predictors of prostate cancer (PCa) diagnosis and recurrence. We compared the expression of a small panel of these biomarkers as a function of race among men undergoing radical prostatectomy (RP). Prostate needle biopsy specimens from 131 patients treated with RP at the Durham Veterans Affairs Medical Center were hematoxylin and eosin stained and immunofluorescent assayed for α-methylacyl CoA racemase (AMACR), androgen receptor (AR) and Ki67. Proprietary image analysis was used to identify six biometric feature combinations that were significantly associated with progression in a previous study. Analysis of population characteristics, stratified by race, was performed using rank-sum and χ2-test. The effect of race on expression of these biomarker profiles was analyzed using multivariate linear regression. All six biomarker features were expressed at higher levels in black men than white men, with Norm AR (P=0.006) and Ki67 (P=0.02) attaining statistical significance. On multivariate analysis, all markers were expressed at higher levels in black men, with Norm AR (P=0.001), Ki67 (P=0.007) and Ki67/lum (P=0.022) reaching significance. These data support the hypothesis that PCa may be biologically more aggressive among black men. [ABSTRACT FROM AUTHOR]

Prostate cryoablation is an established minimally invasive treatment for localized prostate cancer (PCa). However, the impairment of erectile function (EF) is considered a serious complication of the procedure. To investigate the efficacy of erectile aids following cryotherapy, 93 patients who underwent whole gland prostate cryoablation with required complete medical records were analyzed. The changes in postoperative EF were evaluated using the International Index of Erectile Function (IIEF-5) questionnaire. Additionally, independent factors that could have a correlation to the postoperative IIEF-5 score or postoperative Expanded Prostate Cancer Index Composite (EPIC) score were assessed. In the entire cohort, the mean preoperative IIEF-5 score was 7.0±6.2. A total of 72 (77.4%) patients had moderate-to-severe preoperative erectile dysfunction. In longitudinal investigation, the patients using erectile aids showed the ability to recover to baseline after 24 months from cryoablation compared with the patients not using erectile aids. There were significant differences of IIEF-5 scores between these groups at 24 months (7.5 vs 3.0; P=0.025) and 36 months (8.5 vs 3.5; P=0.010). In multivariate analysis, the use of erectile aids correlated with restoration of IIEF-5 scores (odds ratio, 5.11; confidence interval (CI), 1.87-13.96; P<0.001) and lower EPIC sexual bother (coef, 19.61; CI, 0.32-38.89; P=0.046). Our data indicate that on-demand use of erectile aids could help restore EF and reduce sexual bother after whole gland prostate cryoablation. Although, erectile aids could not play a role as an adequate treatment for ED after whole gland prostate cryoablation, these results may aid in the decision-making process for PCa patients with preoperative and postoperative ED who have concern about sexual health-related quality of life. [ABSTRACT FROM AUTHOR]

To evaluate whether race modifies the accuracy of nomograms to predict biochemical recurrence (BCR) after radical prostatectomy among subjects from the Shared Equal Access Regional Cancer Hospital (SEARCH) and Duke Prostate Center (DPC) databases. Retrospective analysis of 1721 and 4511 subjects from the SEARCH and DPC cohorts, respectively. The discrimination accuracy for BCR of seven previously published predictive models was assessed using concordance index and compared between African-American men (AAM) and Caucasian men (CM). AAM represented 44% of SEARCH and 14% of DPC. In both cohorts, AAM were more likely to experience BCR than CM (P<0.01). In SEARCH, the mean concordance index across all seven models was lower in AAM (0.678) than CM (0.715), though the mean difference between CM and AAM was modest (0.037; range 0.015–0.062). In DPC the overall mean concordance index for BCR across all seven nomograms was 0.686. In contrast to SEARCH, the mean concordance index in DPC was higher in AAM (0.717) than CM (0.681), though the mean differences between CM and AAM was modest (−0.036; range −0.078 to −0.004). Across all seven models for predicting BCR, the discriminatory accuracy was better among CM in SEARCH and better among AAM in DPC. The mean difference in discriminatory accuracy of all seven nomograms between AAM and CM was approximately 3–4%. This indicates that currently used predictive models have similar performances among CM and AAM. Therefore, nomograms represent a valid and accurate method to predict BCR regardless of race. [ABSTRACT FROM AUTHOR]

An Eulerian model and a Lagrangian particle model are used to study the dispersion of a contaminant released from a low source in the Stable Boundary Layer (SBL) using two different turbulence parameterisations. The Eulerian model is based on the solution of the advection-diffusion equation by the Laplace transform technique. The Lagrangian model is based on a generalized form of the Langevin equation. The first parameterisation, Degraziaet al. (2000), is based on Taylor’s statistical diffusion theory and the observed spectral properties, supposes a linear combination between shear and buoyancy turbulence. The second, Hanna (1982), is based on observed spectral properties from Minnesota Planetary Boundary Layer (PBL) observations and is widely used in pollutant dispersion models. Considering that these simulations are in the SBL, the analysis of the results shows a reasonably good agreement between the values computed by the models against the experimental ones for the two turbulence parameterisations. [ABSTRACT FROM AUTHOR]