Baseline Basal Cell Hyperplasia Is not Associated With Baseline Lower Urinary Tract Symptoms, Baseline Clinical Prostatitis or Prostate Cancer in Repeat Biopsies.

OBJECTIVES: To evaluate whether the presence of basal cell hyperplasia (BCH) in negative biopsies is associated with concurrent lower urinary tract symptoms (LUTS) and benign prostatic hyperplasia (BPH), clinical prostatitis, and future prostate cancer (PCa) in repeat prostate biopsy. METHODS: We performed a retrospective analysis of 6471 men, 50-75 years old with prostate-specific antigen between 2.5 and 10 ng/ml and prior negative biopsy who were enrolled in the Reduction by Dutasteride of PCa Events trial and underwent a 2-year repeat biopsy. The association between baseline BCH and risk of PCa, BPH/LUTS and clinical prostatitis measured at baseline were evaluated with logistic regression in uni/multivariable analysis, controlling for baseline patient characteristics. RESULTS: Among 6471 men enrolled, 84 (1.3%) had BCH in the baseline prostate biopsy. BCH was associated less chronic inflammation and more prostate atrophy (P < 0.05) and was unrelated to baseline patient characteristics. In both uni/multivariable analyses, BCH was not associated with PCa in repeat biopsy (univariable odds ratio [OR] = 0.98, 95% confidence interval [CI] = 0.53-1.82, P > 0.05; multivariable OR=1.15, 95% CI = 0.61-2.16, P > 0.05), BPH/LUTS (univariable OR = 1.13, 95% CI = 0.71-1.81, P > 0.05; multivariable OR = 1.20, 95% CI = 0.74-1.94, P > 0.05), or clinical prostatitis (univariable OR = 0.56, 95% CI = 0.18-1.81, P > 0.05; multivariable OR = 0.57, 95% CI = 0.18-1.83, P > 0.05). CONCLUSION: Among men undergoing repeat prostate biopsy with a baseline negative biopsy, BCH was associated with more histological atrophy and less chronic prostatitis, but was unrelated to LUTS/BPH, clinical prostatitis or future PCa risk.

The association of atrophy in baseline prostate biopsy and lower prostate cancer grade in radical prostatectomy specimens.

INTRODUCTION: To evaluate whether the presence of prostate atrophy (P.A.) in negative prostate biopsy is associated with prostate cancer (P.C.a) grade at surgical pathology among men who are ultimately diagnosed with P.C.a and undergo radical prostatectomy (R.P.). METHODS: A retrospective analysis was performed of 136 men from the placebo arm of the Reduction by Dutasteride of P.C.a Events (R.E.D.U.C.E.) trial who had a baseline prostate biopsy negative for P.C.a, and were later diagnosed with P.C.a on biopsy and underwent radical prostatectomy over the 4-year study period. The association of baseline P.A. (present/absent) with P.C.a grade (W.H.O./I.S.U.P. grade group 1 or ≥2) at surgical pathology was evaluated with logistic regression in uni- and multivariable analyses, controlling for baseline patient characteristics. RESULTS: P.A. was observed in 74 prostate biopsies (54%). P.A. was not associated with baseline characteristics (age, body mass index, prostate-specific antigen level, prostate volume, race, family history of P.C.a, and digital rectal exam), except for chronic inflammation (p = 0.001). The presence of P.A. in baseline prostate biopsies was associated with lower risk of W.H.O./I.S.U.P. grade group ≥2 P.C.a in R.P. specimens on both univariable (O.R. = 0.39, 95% C.I. = 0.19-0.78, p = 0.008) and multivariable (O.R. = 0.43, 95% C.I. = 0.20-0.92, p = 0.029) analyses. CONCLUSIONS: Among men with a baseline prostate biopsy negative for P.C.a who were later found to have P.C.a and underwent R.P., baseline P.A. is independently associated with lower risk of W.H.O./I.S.U.P. grade group ≥2 P.C.a on surgical pathology. P.A. may be used to identify subjects at lower risk for W.H.O./I.S.U.P. ≥ 2 P.C.a and select optimal candidates for active surveillance.

The combination of histological prostate atrophy and inflammation is associated with lower risk of prostate cancer in biopsy specimens.

BACKGROUND: To evaluate whether the presence of both prostate atrophy (PA) and chronic prostate inflammation (CPI) in the same biopsy and in the same biopsy core are associated with prostate cancer (PCa) risk and grade in repeat biopsies. METHODS: Retrospective analyses of 6132 men who were 50-75 years old undergoing 2-year repeat prostate biopsy after a negative baseline biopsy for PCa in the REduction by DUtasteride of prostate Cancer Events (REDUCE) study. PA, CPI and PCa were determined by central pathology. The association of baseline PA and CPI with 2-year repeat biopsy cancer status and grade was evaluated with χ2 test and logistic regression controlling clinicopathological features. RESULTS: PA, CPI and both were detected in 583 (9.5%), 1063 (17.4%) and 3675 (59.9%) baseline biopsies, respectively. Compared with biopsies with neither PA nor CPI, the presence of PA (odds ratio (OR)=0.73, 95% confidence interval (CI)=0.57-0.93), CPI (OR=0.72, 95% CI=0.58-0.88) and both (OR=0.54, 95% CI=0.45-0.64) were associated with lower PCa risk in the 2-year repeat prostate biopsy. Results were similar in multivariable analysis. Among subjects with both PA and CPI, those with both findings in the same core had even lower PCa risk compared with PA and CPI in different cores (univariable OR=0.68, 95% CI=0.51-0.91; multivariable OR=0.73, 95% CI=0.54-0.99). Combination of PA and CPI was associated with lower risk of high-grade PCa. CONCLUSIONS: The presence of both PA and CPI in baseline biopsies, especially in the same core, was associated with lower PCa risk and grade. The presence and topographical distribution of PA and CPI may be used in PCa risk stratification.

Association of comorbid disease burden at diagnosis with higher tumor grade in men with non-metastatic prostate cancer.

BACKGROUND: While older age is associated with higher tumor grade, it is unknown whether comorbid disease burden has a similar, independent association. We sought to evaluate the impact of comorbid disease burden on tumor grade at diagnosis as indicated by biopsy Gleason score. METHODS: We conducted an observational cohort study of 1260 men newly diagnosed with non-metastatic prostate cancer from 1998 to 2004 at two Veterans Affairs Medical Centers. Multivariable ordinal and multinomial logistic regression were used to evaluate the association between Charlson Comorbidity Index score and biopsy Gleason score. RESULTS: Men with Charlson scores of 2 (odds ratio (OR) 1.8, P<0.001) and 3+ (OR 1.8, P<0.001) had significantly greater odds of higher Gleason scores, compared with men with Charlson scores of 0. In a multinomial logistic regression model predicting Gleason 7 vs ⩾6, only men with Charlson scores of 2 (OR 1.6, P=0.01) had greater odds of having a Gleason 7 tumor, compared with those with Charlson scores of 0. In a multinomial logistic regression model predicting Gleason 8-10 vs ⩽6, those with Charlson scores of 1 (OR 1.6, P=0.047), 2 (OR 2.8, P=0.01) and 3+ (OR 2.9, P=0.001) had higher odds of having a Gleason 8-10 tumor. CONCLUSIONS: Moderate-to-heavy comorbid disease burden at diagnosis may be associated with high tumor grade, independent of age, and is a stronger predictor of Gleason 8-10 than Gleason 7 disease.

Impact of carbohydrate restriction in the context of obesity on prostate tumor growth in the Hi-Myc transgenic mouse model.

BACKGROUND: Previously, we showed that carbohydrate restriction with calorie restriction slowed tumor growth in xenograft mouse prostate cancer models. Herein, we examined the impact of carbohydrate restriction without calorie restriction on tumor development within the context of diet-induced obesity in the Hi-Myc transgenic mouse model of prostate cancer. METHODS: Mice were randomized at 5 weeks of age to ad libitum western diet (WD; 40% fat, 42% carbohydrate; n=39) or ad libitum no carbohydrate ketogenic diet (NCKD; 82% fat, 1% carbohydrate; n=44). At age 3 or 6 months, mice were killed, prostates weighed and prostate histology, proliferation, apoptosis and macrophage infiltration evaluated by hematoxylin and eosin, Ki67, TUNEL and F4/80 staining, respectively. Body composition was assessed by DEXA, serum cytokines measured using multiplex, and Akt/mTOR signaling assessed by Western. RESULTS: Caloric intake was higher in the NCKD group, resulting in elevated body weights at 6 months of age, relative to the WD group (45 g vs 38g; P=0.008). Despite elevated body weights, serum monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-1α levels were lower in NCKD versus WD mice (P=0.046 and P=0.118, respectively), and macrophage infiltration was reduced in prostates of NCKD versus WD mice (P=0.028). Relative Akt phosphorylation and phospho-S6 ribosomal protein levels were reduced in prostates of NCKD versus WD mice. However, while mice randomized to NCKD had smaller prostates after adjustment for body weight at 3 and 6 months (P=0.004 and P=0.002, respectively), NCKD mice had higher rates of adenocarcinoma at 6 months compared to WD mice (100 vs 80%, P=0.04). CONCLUSIONS: Despite higher caloric intake and elevated body weights, carbohydrate restriction lowered serum MCP-1 levels, reduced prostate macrophage infiltration, reduced prostate weight, but failed to slow adenocarcinoma development. Together, these data suggest that although carbohydrate restriction within the context of obesity may reduce obesity-associated systemic inflammation and perhaps slow tumor growth, it is not sufficient to counteract obesity-associated tumor development.

Obesity and prostate cancer-specific mortality after radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database.

BACKGROUND: At the population level, obesity is associated with prostate cancer (PC) mortality. However, few studies analyzed the associations between obesity and long-term PC-specific outcomes after initial treatment. METHODS: We conducted a retrospective analysis of 4268 radical prostatectomy patients within the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Cox models accounting for known risk factors were used to examine the associations between body mass index (BMI) and PC-specific mortality (PCSM; primary outcome). Secondary outcomes included biochemical recurrence (BCR) and castration-resistant PC (CRPC). BMI was used as a continuous and categorical variable (normal <25 kg/m2, overweight 25-29.9 kg/m2 and obese ⩾30 kg/m2). Median follow-up among all men who were alive at last follow-up was 6.8 years (interquartile range=3.5-11.0). During this time, 1384 men developed BCR, 117 developed CRPC and 84 died from PC. Hazard ratios were analyzed using competing-risks regression analysis accounting for non-PC death as a competing risk. RESULTS: On crude analysis, higher BMI was not associated with risk of PCSM (P=0.112), BCR (0.259) and CRPC (P=0.277). However, when BMI was categorized, overweight (hazard ratio (HR) 1.99, P=0.034) and obesity (HR 1.97, P=0.048) were significantly associated with PCSM. Obesity and overweight were not associated with BCR or CRPC (all P⩾0.189). On multivariable analysis adjusting for both clinical and pathological features, results were little changed in that obesity (HR=2.05, P=0.039) and overweight (HR=1.88, P=0.061) were associated with higher risk of PCSM, but not with BCR or CRPC (all P⩾0.114) with the exception that the association for overweight was no longer statistical significant. CONCLUSIONS: Overweight and obesity were associated with increased risk of PCSM after radical prostatectomy. If validated in larger studies with longer follow-up, obesity may be established as a potentially modifiable risk factor for PCSM.

Long-term oncological outcomes of apical positive surgical margins at radical prostatectomy in the Shared Equal Access Regional Cancer Hospital cohort.

BACKGROUND: Approximately 29-38% of all positive surgical margins (PSMs) at radical prostatectomy (RP) involve the apex. The prognostic significance of apical PSM remains unclear. We therefore compared the long-term oncologic outcomes of men with apical PSMs to those with negative PSMs, apical and other PSMs, and other PSMs at RP. METHODS: The SEARCH (Shared Equal Access Regional Cancer Hospital) database was used to identify 4031 men with prostate cancer (PCa) managed with RP with complete pathologic grade and stage data. Margin status was categorized as negative, apex only, or other positive. Multivariable Cox regression models adjusted for pathologic stage and grade were developed to test the relationship between margin status and biochemical recurrence (BCR), metastases and PCa death. RESULTS: In the final cohort, 34.3% had PSMs, whereas 65.7% had negative margins. Univariable analysis showed that compared with negative margins, apex-only PSM was associated with BCR (hazard ratio (HR): 1.4 [1.1-1.8]), but not metastases or PCa death, whereas apex and other PSMs were associated with BCR (HR: 3.3 [2.8-4]) and metastases (HR: 1.8 [1.02-3.1]) but not PCa death. Nonapical PSMs were associated with BCR (HR: 2.7 [2.4-3.1]), metastases (1.7 [1.2-2.5)] and PCa death (1.8 [1.05-3]). On multivariable analysis, apex-only, apex and other, and nonapical PSMs were associated with BCR but margin status was not associated with metastases or PCa death. CONCLUSIONS: In a large cohort of men undergoing RP, those with PSMs at the prostatic apex had lower BCR, metastases, or PCa death compared with those with PSMs at other locations. When adjusted for pathologic stage and grade, however, PSMs were associated with BCR but not long-term oncologic outcomes. These data confirm that men with apex-only PSMs may not be ideal candidates for adjuvant therapy after RP.

Do skeletal-related events predict overall survival in men with metastatic castration-resistant prostate cancer?

BACKGROUND: Skeletal-related events (SREs) including pathologic fracture, spinal cord compression, radiation to bone and surgery to bone, are common in men with bone metastatic castration-resistant prostate cancer (mCRPC). Men with mCRPC are at high risk of death. Whether SREs predict mortality is unclear. We tested the association between SREs and overall survival (OS) in a multiethnic cohort with bone mCRPC, controlling for key covariates unavailable in claims data such as bone pain, number of bone metastases and PSA doubling time (PSADT). METHODS: We collected data on 233 men diagnosed with nonmetastatic castration-resistant prostate cancer (CRPC) in 2000-2013 at two Veterans Affairs hospitals who later progressed to bone metastases. First occurrence of SRE and OS were collected from the medical records. Cox models were used to test the association between SRE and OS, treating SRE as a time-dependent variable. We adjusted for age, year, race, treatment center, biopsy Gleason, primary treatment to the prostate, PSA, PSADT, months from androgen deprivation therapy to CRPC, months from CRPC to metastasis and number of bone metastases at initial bone metastasis diagnosis. In a secondary analysis, we also adjusted for bone pain. RESULTS: During follow-up, 88 (38%) patients had an SRE and 198 (85%) died. After adjusting for risk factors, SRE was associated with increased mortality (hazard ratio (HR)=1.67; 95% confidence interval (CI) 1.22-2.30; P=0.001). When bone pain was added to the model, the association of SREs and OS was attenuated, but remained significant (HR=1.42; 95% CI 1.01-1.99; P=0.042). CONCLUSIONS: SREs are associated with increased mortality in men with bone mCRPC. Further studies on the impact of preventing SREs to increase survival are warranted.

Efficacy of post-operative radiation in a prostatectomy cohort adjusted for clinical and genomic risk.

BACKGROUND: To date, there have been no published trials examining the impact of salvage radiation therapy (SRT) in the post-operative setting for prostate cancer (PCa). We conducted a retrospective, comparative study of post-operative radiation following radical prostatectomy (RP) for men with pT3 disease or positive margins (adverse pathological features, APF). METHODS: 422 PCa men treated at four institutions with RP and having APF were analyzed with a primary end point of metastasis. Adjuvant radiation treatment (ART, n=111), minimal residual disease (MRD) SRT (n=70) and SRT (n=83) were defined by PSA levels of <0.2, 0.2-0.49 and ⩾0.5 ng ml(-1), respectively, before radiation therapy (RT) initiation. Remaining 157 men who did not receive additional therapy before metastasis formed the no RT arm. Clinical-genomic risk was assessed by Cancer of the Prostate Risk Assessment Post-Surgical (CAPRA-S) and Decipher. Cox regression was used to evaluate the impact of treatment on outcome. RESULTS: During the study follow-up, 37 men developed metastasis with a median follow-up of 8 years. Both CAPRA-S and Decipher had independent predictive value on multivariable analysis for metastasis (P<0.05). Adjusting for clinical-genomic risk, SRT and no RT had hazard ratios of 4.31 (95% confidence interval, 1.20-15.47) and 5.42 (95% confidence interval, 1.59-18.44) for metastasis compared with ART, respectively. No significant difference was observed between MRD-SRT and ART (P=0.28). Men with low-to-intermediate CAPRA-S and low Decipher value have a low rate of metastatic events regardless of treatment selection. In contrast, men with high CAPRA-S and Decipher benefit from ART, however the cumulative incidence of metastasis remains high. CONCLUSIONS: The decision as to the timing and need for additional local therapy following RP is nuanced and requires providers and patients to balance risks of morbidity with improved oncological outcomes. Post-RP treatment can be safely avoided for men who are low risk by clinical-genomic risk, whereas those at high risk should favor enrollment in clinical trials.

Baseline subject characteristics predictive of compliance with study-mandated prostate biopsy in men at risk of prostate cancer: results from REDUCE.

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 8025 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, 22% of men did not undergo a 2-year biopsy. On multivariable analysis, the non-North American region was predictive of 42-44% 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 42-48% increased likelihood of undergoing a 2-year biopsy (P<0.001). In addition, black race predicted 44% lower rate of on-study 2-year biopsy (odds ratio (OR)=0.56; P=0.001). Finally, missing one or more baseline variables was associated with a 32% decreased likelihood of undergoing a 2-year biopsy (OR=0.68; P<0.001). 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.

Greater extent of prostate inflammation in negative biopsies is associated with lower risk of prostate cancer on repeat biopsy: results from the REDUCE study.

BACKGROUND: To evaluate whether the extent of baseline acute prostate inflammation (API) and chronic prostate inflammation (CPI) was associated with risk of prostate cancer (PCa) at 2-year repeat prostate biopsy in a clinical trial with systematic biopsies independent of PSA. METHODS: A retrospective analysis of 6065 men with a negative baseline biopsy in the reduction by dutasteride of PCa events (REDUCE) trial undergoing 2-year biopsy. API and CPI extent (percentage of cores involved) and PCa (present or absent) were assessed by central pathology. The association of baseline API and CPI with PCa at the 2-year biopsy was evaluated with logistic regression in uni- and multivariable analyses. RESULTS: API extent was classified as absent or involving 1-25%, 26-50%, 51-75% and >75% cores in 5140 (85%), 742 (12%), 151 (2%), 17 (<1%) and 15 (<1%) cases, respectively. CPI extent was classified as absent or involving 1-25%, 26-50%, 51-75% and >75% cores in 1367 (22%), 2532 (42%), 1474 (24%), 397 (7%) and 295 (5%) cases, respectively. More extensive API was associated with younger age, lower PSA and lower prostate volume, while more extensive CPI was associated with older age, lower PSA and higher prostate volume (all P<0.01). In both uni- and multivariable analyses, API and CPI extent were associated with lower risk of PCa at the 2-year biopsy (both P<0.01). CONCLUSIONS: In a cohort of men undergoing repeat prostate biopsy 2 years after a negative baseline biopsy, a greater extent of baseline API and CPI was independently associated with lower PCa risk.

Evaluation of an epithelial plasticity biomarker panel in men with localized prostate cancer.

BACKGROUND: Given the potential importance of epithelial plasticity (EP) to cancer metastasis, we sought to investigate biomarkers related to EP in men with localized prostate cancer (PC) for the association with time to PSA recurrence and other clinical outcomes after surgery. METHODS: Men with localized PC treated with radical prostatectomy at the Durham VA Medical Center and whose prostatectomy tissues were included in a tissue microarray (TMA) linked to long-term outcomes. We performed immunohistochemical studies using validated antibodies against E-cadherin and Ki-67 and mesenchymal biomarkers including N-cadherin, vimentin, SNAIL, ZEB1 and TWIST. Association studies were conducted for each biomarker with baseline clinical/pathologic characteristics an risk of PSA recurrence over time. RESULTS: Two hundred and five men contributed TMA tissue and had long-term follow-up (median 11 years). Forty-three percent had PSA recurrence; three died of PC. The majority had high E-cadherin expression (86%); 14% had low/absent E-cadherin expression. N-cadherin was rarely expressed (<4%) and we were unable to identify an E-to-N-cadherin switch as independently prognostic. No associations with clinical risk group, PSA recurrence or Gleason sum were noted for SNAIL, ZEB1, vimentin or TWIST, despite heterogeneous expression between patients. We observed an association of higher Ki-67 expression with Gleason sum (P=0.043), National Comprehensive Cancer Network risk (P=0.013) and PSA recurrence (hazard ratio 1.07, P=0.016). CONCLUSIONS: The expression of EP biomarkers in this cohort of men with a low risk of PC-specific mortality was not associated with aggressive features or PSA relapse after surgery.

Which, when and why? Rational use of tissue-based molecular testing in localized prostate cancer.

An increased molecular understanding of localized prostate cancer and the improved ability for molecular testing of pathologic tissue has led to the development of multiple clinical assays. Here we review the relevant molecular biology of localized prostate cancer, currently available tissue-based tests and describe which is best supported for use in various clinical scenarios. Literature regarding testing of human prostate cancer tissue with Ki-67, PTEN (by immunohistochemistry (IHC) or fluroescence in situ hybridization (FISH)), ProMark, Prolaris, OncotypeDX Prostate and Decipher was reviewed to allow for generation of expert opinions. At diagnosis, evaluation of PTEN status, use of ProMark or OncotypeDX Prostate in men with Gleason 6 or 3+4=7 disease may help guide the use of active surveillance. For men with Gleason 7 or above disease considering watchful waiting, Ki-67 and Prolaris add independent prognostic information. For those men who have undergone prostatectomy and have adverse pathology, Decipher testing may aid in the decision to undergo adjuvant radiation. Newly available molecular tests bring opportunities to improve decision making for men with localized prostate cancer. A review of the currently available data suggests clinical scenarios for which each of these tests may have the greatest utility.

Predicting bone scan positivity in non-metastatic castration-resistant prostate cancer.

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.

A urine-based methylation signature for risk stratification within low-risk prostate cancer.

BACKGROUND: Prostate cancer overdiagnosis and overtreatment represents a major problem. Many men with low-grade disease on biopsy are undergraded and they harbour high-grade disease at prostatectomy with no reliable way to identify these men. We used a novel urine-based 2-gene methylation test to identify prostate cancers with aggressive features. METHODS: Following a proof of concept study in 100 post-radical prostatectomy tissue samples, urine samples were tested from 665 men at multiple U.S. centers undergoing prostate needle biopsy for elevated prostate-specific antigen (2-10 ng ml(-1)). A prediction model was then developed from a combination of clinical factors and the urine-based markers. It was then prospectively tested for accurate prediction of adverse disease (surgical Gleason score ⩾7 and/or a pathological stage ⩾T3a) using urine from a separate cohort of 96 men before radical prostatectomy. RESULTS: Among pre-prostatectomy men with a biopsy Gleason score <7, 41% had adverse disease of which 100% were correctly identified by the test with a negative predictive value of 100% (95% confidence interval, 86-100%). CONCLUSIONS: This urine-based test accurately identifies men with clinical low-risk disease who do not have adverse pathology in their prostates and would be excellent candidates for active surveillance.

Predicting bone scan positivity after biochemical recurrence following radical prostatectomy in both hormone-naive men and patients receiving androgen-deprivation therapy: results from the SEARCH database.

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.

Metformin does not affect risk of biochemical recurrence following radical prostatectomy: results from the SEARCH database.

BACKGROUND: While epidemiologic studies suggest that metformin use among diabetics may decrease prostate cancer (PC) incidence, the effect of metformin use on PC outcome is unclear. We investigated the association between pre-operative metformin use, dose and duration of use and biochemical recurrence (BCR) in PC patients with diabetes who underwent radical prostatectomy (RP). METHODS: We conducted a retrospective cohort analysis within the Shared Equal Access Regional Cancer Hospital (SEARCH) database of 371 PC patients with diabetes who underwent RP. Time to BCR between metformin users and non-users, and by metformin dose and duration of use was assessed using multivariable Cox proportional analysis adjusted for demographic, clinical and/or pathologic features. Time to castrate-resistant PC (CRPC), metastases and PC-specific mortality were explored as secondary outcomes using unadjusted analyses. RESULTS: Of 371 diabetic men, 156 (42%) were using metformin before RP. Metformin use was associated with more recent year of surgery (P<0.0001) but no clinical or pathologic characteristics. After adjustment for year of surgery, clinical and pathologic features, there were no associations between metformin use (hazard ratio (HR) 0.93; 95% confidence interval (CI) 0.61-1.41), high metformin dose (HR 0.96; 95% CI 0.57-1.61) or duration of use (HR 1.00; 95% CI 0.99-1.02) and time to BCR. A total of 14 patients (3.8%) developed CRPC, 10 (2.7%) distant metastases and 8 (2.2%) died from PC. Unadjusted analysis suggested that high metformin dose vs non-use was associated with increased risk of CRPC (HR 5.1; 95% CI 1.6-16.5), metastases (HR 4.8; 95% CI 1.2-18.5) and PC-specific mortality (HR 5.0; 95% CI 1.1-22.5). CONCLUSIONS: Metformin use, dose or duration of use was not associated with BCR in this cohort of diabetic PC patients treated with RP. The suggestion that higher metformin dose was associated with increased risk of CRPC, metastases and PC-specific mortality merits testing in large prospective studies with longer follow-up.

Fish oil slows prostate cancer xenograft growth relative to other dietary fats and is associated with decreased mitochondrial and insulin pathway gene expression.

BACKGROUND: Previous mouse studies suggest that decreasing dietary fat content can slow prostate cancer (PCa) growth. To our knowledge, no study has yet compared the effect of multiple different fats on PCa progression. We sought to systematically compare the effect of fish oil, olive oil, corn oil and animal fat on PCa progression. METHODS: A total of 96 male severe combined immunodeficient mice were injected with LAPC-4 human PCa cells. Two weeks following injection, mice were randomized to a Western diet based on fish oil, olive oil, corn oil or animal fat (35% kilocalories from fat). Animals were euthanized when tumor volumes reached 1000 mm(3). Serum was collected at death and assayed for PSA, insulin, insulin-like growth factor-1 (IGF-1), IGF-1-binding protein-3 and prostaglandin E-2 (PGE-2) levels. Tumors were also assayed for PGE-2 and cyclooxygenase-2 levels, and global gene expression was analyzed using Affymetrix microarrays. RESULTS: Mice weights and tumor volumes were equivalent across groups at randomization. Overall, fish oil consumption was associated with improved survival relative to other dietary groups (P=0.014). On gene expression analyses, the fish oil group had decreased signal in pathways related to mitochondrial physiology and insulin synthesis/secretion. CONCLUSIONS: In this xenograft model, we found that consuming a diet in which fish oil was the only fat source slowed tumor growth and improved survival compared with that in mice consuming diets composed of olive oil, corn oil or animal fat. Although prior studies showed that the amount of fat is important for PCa growth, this study suggests that the type of dietary fat consumed may also be important.

Statin use and risk of prostate cancer and high-grade prostate cancer: results from the REDUCE study.

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.

Race is associated with discontinuation of active surveillance of low-risk prostate cancer: results from the Duke Prostate Center.

BACKGROUND: Active surveillance (AS) is increasingly utilized in low-risk prostate cancer (PC) patients. Although black race has traditionally been associated with adverse PC characteristics, its prognostic value for patients managed with AS is unclear. METHODS: A retrospective review identified 145 patients managed with AS at the Duke Prostate Center from January 2005 to September 2011. Race was patient-reported and categorized as black, white or other. Inclusion criteria included PSA <10 ng ml(-1), Gleason sum ≤ 6, and ≤ 33% of cores with cancer on diagnostic biopsy. The primary outcome was discontinuation of AS for treatment due to PC progression. In men who proceeded to treatment after AS, the trigger for treatment, follow-up PSA and biopsy characteristics were analyzed. Time to treatment was analyzed with univariable and multivariable Cox proportional hazards models and also stratified by race. RESULTS: In our AS cohort, 105 (72%) were white, 32 (22%) black and 8 (6%) another race. Median follow-up was 23.0 months, during which 23% percent of men proceeded to treatment. The demographic, clinical and follow-up characteristics did not differ by race. There was a trend toward more uninsured black men (15.6% black, 3.8% white, 0% other, P = 0.06). Black race was associated with treatment (hazard ratio (HR) 2.93, P = 0.01) as compared with white. When the analysis was adjusted for socioeconomic and clinical parameters at the time of PC diagnosis, black race remained the sole predictor of treatment (HR 3.08, P = 0.01). Among men undergoing treatment, the trigger was less often patient driven in black men (8 black, 33 white, 67% other, P = 0.05). CONCLUSIONS: Black race was associated with discontinuation of AS for treatment. This relationship persisted when adjusted for socioeconomic and clinical parameters.