Current routines for antibiotic prophylaxis prior to transrectal prostate biopsy: a national survey to all urology clinics in Sweden.

Background: The risk of infection after transrectal ultrasound (TRUS)-guided prostate biopsies is increasing. The aim of the study was to assess the use of antibiotic prophylaxis for prostate biopsy in Sweden. Methods: All public and private urology clinics reporting to the National Prostate Cancer Register of Sweden received a survey on TRUS-biopsy prophylaxis. Results: Of the 84 clinics surveyed, 76 replied (90%). If no risk factors for infection were present, a single dose of ciprofloxacin 750 mg was used by 50 clinics (66%). Multiple doses of ciprofloxacin 500 or 750 mg (n=14; 18%) or a single dose of trimethoprim-sulfamethoxazole 160/800 mg (n=7; 9%) were other common prophylaxes. Most clinics gave the prophylaxes immediately before the biopsy (n=41; 54%). Urine dipstick was used by 30 clinics (39%) and rectal enema by six (8%). In patients with high risk of infection, the survey mirrors a large variety of regiments used. Conclusions: The preference to use a single dose of ciprofloxacin 750 mg is in accordance with the Swedish national guidelines for patients with a low risk of infection. Better compliance to the guideline recommendation to use a urine dipstick would probably increase the number of patients classified as having an increased risk of infection. Being classified as a high-risk patient should lead to an extended duration of antibiotic prophylaxis, however, the variety of regimens used in the high-risk group reflects an inability to treat these patients in a standardized fashion and also highlights a need for more clear-cut guidelines. Pre-biopsy identification of high-risk patients is an important issue to tackle for the urologic clinics in order to reduce the number of infections.

Predicting Prostate Cancer Death with Different Pretreatment Risk Stratification Tools: A Head-to-head Comparison in a Nationwide Cohort Study.

BACKGROUND: Numerous pretreatment risk classification tools are available for prostate cancer. Which tool is best in predicting prostate cancer death is unclear. OBJECTIVE: To systematically compare the prognostic performance of the most commonly used pretreatment risk stratification tools for prostate cancer. DESIGN, SETTING, AND PARTICIPANTS: A nationwide cohort study was conducted, including 154 811 men in Prostate Cancer data Base Sweden (PCBaSe) 4.0 diagnosed with nonmetastatic prostate cancer during 1998-2016 and followed through 2016. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We compared the D'Amico, National Institute for Health and Care Excellence (NICE), European Association of Urology (EAU), Genito-Urinary Radiation Oncologists of Canada (GUROC), American Urological Association (AUA), National Comprehensive Cancer Network (NCCN), and Cambridge Prognostic Groups (CPG) risk group systems; the Cancer of the Prostate Risk Assessment (CAPRA) score; and the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram in predicting prostate cancer death by estimating the concordance index (C-index) and the observed versus predicted cumulative incidences at different follow-up times. RESULTS AND LIMITATIONS: A total of 139 515 men were included in the main analysis, of whom 15 961 died from prostate cancer during follow-up. The C-index at 10 yr of follow-up ranged from 0.73 (95% confidence interval [CI]: 0.72-0.73) to 0.81 (95% CI: 0.80-0.81) across the compared tools. The MSKCC nomogram (C-index: 0.81, 95% CI: 0.80-0.81), CAPRA score (C-index: 0.80, 95% CI: 0.79-0.81), and CPG system (C-index: 0.78, 95% CI: 0.78-0.79) performed the best. The order of performance between the tools remained in analyses stratified by primary treatment and year of diagnosis. The predicted cumulative incidences were close to the observed ones, with some underestimation at 5 yr. It is a limitation that the study was conducted solely in a Swedish setting (ie, case mix). CONCLUSIONS: The MSKCC nomogram, CAPRA score, and CPG risk grouping system performed better in discriminating prostate cancer death than the D'Amico and D'Amico-derived systems (NICE, GUROC, EAU, AUA, and NCCN). Use of these tools may improve clinical decision making. PATIENT SUMMARY: There are numerous pretreatment risk classification tools that can aid treatment decision for prostate cancer. We systematically compared the prognostic performance of the most commonly used tools in a large cohort of Swedish men with prostate cancer. The Memorial Sloan Kettering Cancer Center nomogram, Cancer of the Prostate Risk Assessment score, and Cambridge Prognostic Groups performed best in predicting prostate cancer death. The use of these tools may improve treatment decisions.

Circulating isoflavone and lignan concentrations and prostate cancer risk: a meta-analysis of individual participant data from seven prospective studies including 2,828 cases and 5,593 controls.

Phytoestrogens may influence prostate cancer development. This study aimed to examine the association between prediagnostic circulating concentrations of isoflavones (genistein, daidzein, equol) and lignans (enterolactone and enterodiol) and the risk of prostate cancer. Individual participant data were available from seven prospective studies (two studies from Japan with 241 cases and 503 controls and five studies from Europe with 2,828 cases and 5,593 controls). Because of the large difference in circulating isoflavone concentrations between Japan and Europe, analyses of the associations of isoflavone concentrations and prostate cancer risk were evaluated separately. Prostate cancer risk by study-specific fourths of circulating concentrations of each phytoestrogen was estimated using multivariable-adjusted conditional logistic regression. In men from Japan, those with high compared to low circulating equol concentrations had a lower risk of prostate cancer (multivariable-adjusted OR for upper quartile [Q4] vs. Q1 = 0.61, 95% confidence interval [CI] = 0.39-0.97), although there was no significant trend (OR per 75 percentile increase = 0.69, 95 CI = 0.46-1.05, ptrend = 0.085); Genistein and daidzein concentrations were not significantly associated with risk (ORs for Q4 vs. Q1 = 0.70, 0.45-1.10 and 0.71, 0.45-1.12, respectively). In men from Europe, circulating concentrations of genistein, daidzein and equol were not associated with risk. Circulating lignan concentrations were not associated with the risk of prostate cancer, overall or by disease aggressiveness or time to diagnosis. There was no strong evidence that prediagnostic circulating concentrations of isoflavones or lignans are associated with prostate cancer risk, although further research is warranted in populations where isoflavone intakes are high.

A combinatorial screen of the CLOUD uncovers a synergy targeting the androgen receptor.

Approved drugs are invaluable tools to study biochemical pathways, and further characterization of these compounds may lead to repurposing of single drugs or combinations. Here we describe a collection of 308 small molecules representing the diversity of structures and molecular targets of all FDA-approved chemical entities. The CeMM Library of Unique Drugs (CLOUD) covers prodrugs and active forms at pharmacologically relevant concentrations and is ideally suited for combinatorial studies. We screened pairwise combinations of CLOUD drugs for impairment of cancer cell viability and discovered a synergistic interaction between flutamide and phenprocoumon (PPC). The combination of these drugs modulates the stability of the androgen receptor (AR) and resensitizes AR-mutant prostate cancer cells to flutamide. Mechanistically, we show that the AR is a substrate for γ-carboxylation, a post-translational modification inhibited by PPC. Collectively, our data suggest that PPC could be repurposed to tackle resistance to antiandrogens in prostate cancer patients.

Selenium and Prostate Cancer: Analysis of Individual Participant Data From Fifteen Prospective Studies.

BACKGROUND: Some observational studies suggest that a higher selenium status is associated with a lower risk of prostate cancer but have been generally too small to provide precise estimates of associations, particularly by disease stage and grade. METHODS: Collaborating investigators from 15 prospective studies provided individual-participant records (from predominantly men of white European ancestry) on blood or toenail selenium concentrations and prostate cancer risk. Odds ratios of prostate cancer by selenium concentration were estimated using multivariable-adjusted conditional logistic regression. All statistical tests were two-sided. RESULTS: Blood selenium was not associated with the risk of total prostate cancer (multivariable-adjusted odds ratio [OR] per 80 percentile increase = 1.01, 95% confidence interval [CI] = 0.83 to 1.23, based on 4527 case patients and 6021 control subjects). However, there was heterogeneity by disease aggressiveness (ie, advanced stage and/or prostate cancer death, Pheterogeneity = .01), with high blood selenium associated with a lower risk of aggressive disease (OR = 0.43, 95% CI = 0.21 to 0.87) but not with nonaggressive disease. Nail selenium was inversely associated with total prostate cancer (OR = 0.29, 95% CI = 0.22 to 0.40, Ptrend < .001, based on 1970 case patients and 2086 control subjects), including both nonaggressive (OR = 0.33, 95% CI = 0.22 to 0.50) and aggressive disease (OR = 0.18, 95% CI = 0.11 to 0.31, Pheterogeneity = .08). CONCLUSIONS: Nail, but not blood, selenium concentration is inversely associated with risk of total prostate cancer, possibly because nails are a more reliable marker of long-term selenium exposure. Both blood and nail selenium concentrations are associated with a reduced risk of aggressive disease, which warrants further investigation.

Clinical characteristics and primary management of patients diagnosed with prostate cancer between 2007 and 2013: status from a Danish primary referral center.

BACKGROUND: The Danish Cancer Registry holds information on all prostate cancers (PCa) cases, including diagnostic TNM. However, stratification according to contemporary risk classification is not possible because histopathological grading and prostate-specific antigen (PSA) level are not registered. The objective of the study was to report clinical characteristics and primary management of men diagnosed with PCa from a primary referral center in Denmark. MATERIAL AND METHODS: Records on all men diagnosed with PCa at the Department of Urology, Frederiksberg Hospital, 1 January 2007 - 31 December 2013, were reviewed. Clinical characteristics and primary treatment were recorded. The National Comprehensive Cancer Network risk group classification was used. RESULTS: A total of 1934 men with a median age of 69 years (interquartile range 65-75) were diagnosed with PCa in the study period resulting in an incidence rate (World Standard Population) of 84/100 000. Overall, 18% were classified as low-risk, 34% as intermediate-risk, 23% as high-risk, 8% as very high-risk and 17% had metastatic disease at diagnosis. Among men age <65 years 70% had low- or intermediate-risk disease, while this was the case for 58% of men aged 65-75 and 22% of men aged >75. Metastatic disease was found in 11% of men <65 years, 17% of men 65-75 years and 23% of men >75 years. In total 73% of men with low-risk PCa were managed on watchful waiting or active surveillance. Curatively intended treatment was performed in 56% of men with intermediate-risk and 61% of men with high-risk PCa, while hormonal therapy was used in 90% of men with very high-risk and 98% of men with metastatic PCa. CONCLUSION: In a population without systematic PSA testing we found a large proportion of patients presenting with advanced PCa at diagnosis. Elderly patients presented with more advanced disease. Curative treatment was primarily used in younger men with clinically localized PCa.

Circulating Folate and Vitamin B12 and Risk of Prostate Cancer: A Collaborative Analysis of Individual Participant Data from Six Cohorts Including 6875 Cases and 8104 Controls.

BACKGROUND: Folate and vitamin B12 are essential for maintaining DNA integrity and may influence prostate cancer (PCa) risk, but the association with clinically relevant, advanced stage, and high-grade disease is unclear. OBJECTIVE: To investigate the associations between circulating folate and vitamin B12 concentrations and risk of PCa overall and by disease stage and grade. DESIGN, SETTING, AND PARTICIPANTS: A study was performed with a nested case-control design based on individual participant data from six cohort studies including 6875 cases and 8104 controls; blood collection from 1981 to 2008, and an average follow-up of 8.9 yr (standard deviation 7.3). Odds ratios (ORs) of incident PCa by study-specific fifths of circulating folate and vitamin B12 were calculated using multivariable adjusted conditional logistic regression. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Incident PCa and subtype by stage and grade. RESULTS AND LIMITATIONS: Higher folate and vitamin B12 concentrations were associated with a small increase in risk of PCa (ORs for the top vs bottom fifths were 1.13 [95% confidence interval (CI), 1.02-1.26], ptrend=0.018, for folate and 1.12 [95% CI, 1.01-1.25], ptrend=0.017, for vitamin B12), with no evidence of heterogeneity between studies. The association with folate varied by tumour grade (pheterogeneity<0.001); higher folate concentration was associated with an elevated risk of high-grade disease (OR for the top vs bottom fifth: 2.30 [95% CI, 1.28-4.12]; ptrend=0.001), with no association for low-grade disease. There was no evidence of heterogeneity in the association of folate with risk by stage or of vitamin B12 with risk by stage or grade of disease (pheterogeneity>0.05). Use of single blood-sample measurements of folate and B12 concentrations is a limitation. CONCLUSIONS: The association between higher folate concentration and risk of high-grade disease, not evident for low-grade disease, suggests a possible role for folate in the progression of clinically relevant PCa and warrants further investigation. PATIENT SUMMARY: Folate, a vitamin obtained from foods and supplements, is important for maintaining cell health. In this study, however, men with higher blood folate levels were at greater risk of high-grade (more aggressive) prostate cancer compared with men with lower folate levels. Further research is needed to investigate the possible role of folate in the progression of this disease.

Upper limit of cancer extent on biopsy defining very low-risk prostate cancer.

OBJECTIVE: To investigate how much Gleason pattern 3 cancer prostate biopsy specimens may contain without an increased risk of undetected more aggressive cancer, compared with the risk for cancers fulfilling the National Comprehensive Cancer Network (NCCN) criteria for very low-risk prostate cancer. PATIENTS AND METHODS: We identified 1286 men aged <70 years in the National Prostate Cancer Register of Sweden who underwent primary radical prostatectomy (RP) for stage T1c or T2 prostate cancer with Gleason pattern ≤3 only, prostate-specific antigen (PSA) level of <10 ng/mL and a PSA density of <0.15 ng/mL/mL. The association between the extent of cancer in the biopsies (the number and proportion of positive cores and the total cancer length in the cores in millimetres) and the likelihood of Gleason pattern 4-5 in the RP specimen was analysed with logistic regression. RESULTS: In all, 438 (34%) of the 1286 men had Gleason pattern 4-5 in the RP specimen. Increasing number and proportion of positive biopsy cores, as well as increasing biopsy cancer length were both significantly associated with increased risk of upgrading at RP in univariable analysis, but in multivariable analysis only biopsy cancer length remained significant. The 684 men with stage T1c and <8 mm cancer had similar risk of upgrading regardless of whether the number of positive biopsy cores was 1-2 or 3-4 (28% vs 27% risk); upgrading was more common among the remaining men (40%, P < 0.01). CONCLUSIONS: Men aged <70 years with stage T1c prostate cancer and 3-4 biopsy cores with Gleason pattern 3 are not more likely to have undetected Gleason pattern 4-5 cancer than men with 1-2 cores with cancer, provided that the total biopsy cancer length is <8 mm. We propose that the definition of very low-risk prostate cancer is widened accordingly.

High density of S100A9 positive inflammatory cells in prostate cancer stroma is associated with poor outcome.

PURPOSE: To elucidate if the density of inflammatory cells expressing S100A9 in malignant and surrounding non-malignant prostate tissues is a prognostic marker for outcome in prostate cancer patients. EXPERIMENTAL DESIGN: Tissue was obtained from 358 men diagnosed with prostate cancer at transurethral resection of the prostate due to obstructive voiding problems, of which 260 were then followed with watchful waiting. Tissue microarrays of both malignant and non-malignant tissues were stained with an antibody against S100A9. The number of stained inflammatory cells was scored and related to clinical outcome and histopathological parameters of known prognostic value. RESULTS: A high number of inflammatory cells expressing S100A9 in both malignant and surrounding non-malignant tissues were associated with significantly shorter cancer-specific survival. This association remained significant when Gleason score and local tumour stage were analysed together with S100A9 in a Cox regression model. Low number of S100A9 positive cells in non-malignant stroma was correlated to significantly longer cancer-specific survival also in patients with Gleason score 8-10 tumours. S100A9 positive cells in tumour stroma were correlated with Gleason score, hyaluronan, platelet-derived growth factor receptor beta (PDGFR-ß), and androgen receptor (inverse correlation) in tumour stroma. S100A9 positive cells in non-malignant stroma correlated with androgen receptor in this tissue compartment (inverse correlation). CONCLUSIONS: A high number of S100A9 positive inflammatory cells in tumour stroma and in non-malignant stroma were associated with shorter cancer-specific survival in prostate cancer patients.

Thromboembolic events following surgery for prostate cancer.

BACKGROUND: Prostate cancer (PCa) and surgery are both associated with increased risk of thromboembolic diseases (TED). OBJECTIVE: We assessed risk of TED among men undergoing different types of urologic surgery. DESIGN, SETTING, AND PARTICIPANTS: Using the Prostate Cancer Database Sweden (PCBaSe) Sweden, we identified all men (n=45 065) undergoing pelvic lymph node dissection (PLND), radical prostatectomy (RP) with or without PLND, orchiectomy due to PCa, or a transurethral resection of the prostate (TURP). We identified a comparison cohort from the population. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Main outcomes were deep venous thrombosis (DVT) and pulmonary embolism (PE) as primary diagnoses in the National Patient Register or Cause of Death Register (2002-2010). We calculated hazard ratios (HR) and 95% confidence intervals (CI) using multivariable Cox proportional hazards models. RESULTS AND LIMITATIONS: All surgical procedures were associated with increased risk of TED; laparoscopic and open RP with a PLND were the most strongly associated with TED (HR for PE: 8.1 [95% CI, 2.9-23.0] and 7.8 [95% CI, 4.9-13], respectively). For surgery including a PLND, the risk increased during the second half of the first postoperative month. The HR for PE after TURP in men with PCa was 3.0 (95% CI, 1.8-5.1). Patients with a history of TED had a strongly increased risk of TED (HR for DVT: 4.5; 95% CI, 2.6-8.0). A limitation is lack of information on TED prophylaxis, but its use was standardized during the study period for RP and PLND. Other limitations are lack of information on extent of PLND and lifestyle factors. CONCLUSIONS: Surgeries for PCa, including TURP, are associated with hospitalization for TED. Patients with a history of TED and patients undergoing a PLND were at highest risk. The largest risk was observed from days 14 to 28 postoperatively. Thus, our results suggest that prophylactic measures may be beneficial during the first 4 wk in these patients.

Fatty acid patterns and risk of prostate cancer in a case-control study nested within the European Prospective Investigation into Cancer and Nutrition.

BACKGROUND: Fatty acids in blood may be related to the risk of prostate cancer, but epidemiologic evidence is inconsistent. Blood fatty acids are correlated through shared food sources and common endogenous desaturation and elongation pathways. Studies of individual fatty acids cannot take this into account, but pattern analysis can. Treelet transform (TT) is a novel method that uses data correlation structures to derive sparse factors that explain variation. OBJECTIVE: The objective was to gain further insight in the association between plasma fatty acids and risk of prostate cancer by applying TT to take data correlations into account. DESIGN: We reanalyzed previously published data from a case-control study of prostate cancer nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. TT was used to derive factors explaining the variation in 26 plasma phospholipid fatty acids of 962 incident prostate cancer cases matched to 1061 controls. Multiple imputation was used to deal with missing data in covariates. ORs of prostate cancer according to factor scores were determined by using multivariable conditional logistic regression. RESULTS: Four simple factors explained 38% of the variation in plasma fatty acids. A high score on a factor reflecting a long-chain n-3 PUFA pattern was associated with greater risk of prostate cancer (OR for highest compared with lowest quintile: 1.36; 95% CI: 0.99, 1.86; P-trend = 0.041). CONCLUSION: Pattern analyses using TT groupings of correlated fatty acids indicate that intake or metabolism of long-chain n-3 PUFAs may be relevant to prostate cancer etiology.

Current routines for transrectal ultrasound-guided prostate biopsy: a web-based survey by the Swedish Urology Network.

OBJECTIVE: This study aimed to survey current Swedish practices for performing and handling transrectal ultrasound-guided prostate biopsies. MATERIAL AND METHODS: A Swedish Urology Network (SUNe) was organized for the distribution of information, survey studies and research collaborations. A web-based questionnaire was distributed to the members in 2011. RESULTS: In this first SUNe survey, 137 (91%) of the 151 members replied. All used antibiotic prophylaxis (84% ciprofloxacin, 12% trimethoprim-sulfamethoxazole), most commonly (63%) as a single dose of ciprofloxacin. Local anaesthesia was used by 87%. Half of the respondents only used a "side-fire" probe, whereas 17% always used an "end-fire" probe. Most (84%) routinely took 10 or more biopsy cores. About three-quarters started with the right base of the prostate and did not routinely take midline biopsies. More than one-third never or rarely sampled the anterior part of the prostate. There was great variability in how biopsy location was reported, but 71% considered a national standardized coordinate system desirable. Fine-needle aspiration was used occasionally by 39%, in more than 10% of cases by 6% and always by 2%. Most urologists mounted the biopsy cores on paper before fixation (78%), put only one core per jar (75%) and used flat-bottomed jars (70%). CONCLUSIONS: Most routines for handling of prostate biopsies, antibiotic prophylaxis, local anaesthesia and number of cores were uniform. However, there is still a need for standardization of the performance of ultrasound-guided biopsies. Although the method used to specify biopsy location varied greatly, most urologists would prefer a national standardized system.

Low levels of phosphorylated epidermal growth factor receptor in nonmalignant and malignant prostate tissue predict favorable outcome in prostate cancer patients.

PURPOSE: To explore if the expression of phosphorylated epidermal growth factor receptor (pEGFR) in nonmalignant and malignant prostate tissue is a potential prognostic marker for outcome in prostate cancer patients. EXPERIMENTAL DESIGN: We used formalin-fixed tissues obtained through the transurethral resection of the prostate from 259 patients diagnosed with prostate cancer after the transurethral resection of the prostate, and patients were then followed with watchful waiting. Tissue microarrays of nonmalignant and malignant prostate tissue were stained with an antibody against pEGFR. The staining pattern was scored and related to clinicopathologic parameters and to outcome. RESULTS: Low phosphorylation of EGFR in prostate epithelial cells, both in the tumor and surprisingly also in the surrounding nonmalignant tissue, was associated with significantly longer cancer-specific survival in prostate cancer patients. This association remained significant when Gleason score and local tumor stage were added together with pEGFR to a Cox regression model. Tumor epithelial pEGFR immunoreactivity was significantly correlated to tumor cell proliferation, tumor vascular density, and nonmalignant epithelial pEGFR immunoreactivity. Patients with metastases had significantly higher immunoreactivity for tumor and nonmalignant epithelial pEGFR compared with patients without metastases. CONCLUSIONS: Low pEGFR immunoreactivity is associated with the favorable prognosis in prostate cancer patients and may provide information about which patients with Gleason score 6 and 7 tumors that will survive their disease even without treatment. Changes in the nonmalignant tissue adjacent to prostate tumors give prognostic information.

Plasma selenium concentration and prostate cancer risk: results from the European Prospective Investigation into Cancer and Nutrition (EPIC).

BACKGROUND: Some evidence indicates that a low selenium intake may be associated with an increased risk of prostate cancer. OBJECTIVE: The aim of this study was to investigate the association of plasma selenium concentration with subsequent prostate cancer risk and to examine this association by stage and grade of disease and other factors. DESIGN: A nested case-control study was performed among men in the European Prospective Investigation into Cancer and Nutrition (EPIC). The association between plasma selenium concentration and prostate cancer risk was assessed in 959 men with incident prostate cancer and 1059 matched controls. RESULTS: Overall, plasma selenium concentration was not associated with prostate cancer risk; the multivariate relative risk for men in the highest fifth of selenium concentration compared with the lowest fifth was 0.96 (95% CI: 0.70, 1.31; P for trend = 0.25). There were no significant differences in the association of plasma selenium with risk when analyzed by stage or grade of disease. Similarly, the association of selenium with risk did not differ by smoking status or by plasma alpha- or gamma-tocopherol concentration. CONCLUSION: Plasma selenium concentration was not associated with prostate cancer risk in this large cohort of European men.

Tumor size, vascular density and proliferation as prognostic markers in GS 6 and GS 7 prostate tumors in patients with long follow-up and non-curative treatment.

OBJECTIVES: To investigate the prognostic value of potential markers in localized, Gleason score 6 and 7 prostate cancer (PC). METHODS: From a consecutive series of men with PC diagnosed at transurethral resection (1975-1990), specimens from 132 patients without metastases, with Gleason score (GS) 6 (n=80) or 7 (n=52) tumors followed with watchful waiting were examined. The fraction of resected prostate tissue containing cancer, the micro-vessel density (v.d.) when stained for endoglin or von Willebrand factor (vWf), and the percentage of Ki-67 labeled tumor cells were measured using immunohistochemistry. RESULTS: High levels of vWf v.d., endoglin v.d., and percent cancer of the TURP specimen were significantly associated with short cancer-specific survival in Kaplan-Meier analysis of all patients with GS 6 and 7 tumors. Interestingly, a combined estimate of percent cancer and vWF v.d. could be used to identify a large subset (50%) of GS 6 tumors with only a 2.5% risk of PC death within 15 years. None of the tested markers gave independent prognostic information for the GS 7 tumors. CONCLUSIONS: Estimates of tumor size and vascular density may identify a large proportion of non-aggressive GS 6, but not GS 7, tumors.

Anticancer effects of a plant lignan 7-hydroxymatairesinol on a prostate cancer model in vivo.

Clinical intervention studies and experimental studies with lignan-rich diets suggest that lignans may have inhibitory effects on prostate cancer, but no clinical or experimental studies with purified lignans have been published. The purpose of this study was to investigate the effect of a plant lignan 7-hydroxymatairesinol (HMR) on LNCaP human prostate cancer xenografts in athymic mice. Athymic nude male mice were injected subcutaneously with LNCaP cells. Starting 3 days after tumor cell injections, a control diet or a control diet supplemented with 0.15% or 0.30% of HMR was administered to mice and the tumor take rate and growth was observed for 9 weeks. HMR diet inhibited the growth of LNCaP tumors. Mice treated with HMR had smaller tumor volume, lower tumor take rate, increased proportion of nongrowing tumors, and higher tumor cell apoptotic index compared with controls. Furthermore, the cell proliferation index was reduced in mice receiving the 0.30% HMR diet compared with mice receiving the control diet. Our results suggest that dietary HMR started at the early phase of the tumor development inhibits the growth of the LNCaP human prostate cancer xenografts in athymic male mice.

Both high and low levels of blood vitamin D are associated with a higher prostate cancer risk: a longitudinal, nested case-control study in the Nordic countries.

Vitamin D inhibits the development and growth of prostate cancer cells. Epidemiologic results on serum vitamin D levels and prostate cancer risk have, however, been inconsistent. We conducted a longitudinal nested case-control study on Nordic men (Norway, Finland and Sweden) using serum banks of 200,000 samples. We studied serum 25(OH)-vitamin D levels of 622 prostate cancer cases and 1,451 matched controls and found that both low (/=80 nmol/l) 25(OH)-vitamin D serum concentrations are associated with higher prostate cancer risk. The normal average serum concentration of 25(OH)-vitamin D (40-60 nmol/l) comprises the lowest risk of prostate cancer. The U-shaped risk of prostate cancer might be due to similar 1,25-dihydroxyvitamin D(3) availability within the prostate: low vitamin D serum concentration apparently leads to a low tissue concentration and to weakened mitotic control of target cells, whereas a high vitamin D level might lead to vitamin D resistance through increased inactivation by enhanced expression of 24-hydroxylase. It is recommended that vitamin D deficiency be supplemented, but too high vitamin D serum level might also enhance cancer development.

Prospective study of plasma enterolactone and prostate cancer risk (Sweden).

OBJECTIVES: Enterolactone, a phytoestrogen produced by the intestinal microflora from precursors in plant foods, has been postulated to protect against hormone-dependent cancers. We studied the association between plasma enterolactone and risk of prostate cancer. METHODS: In the Northern Sweden Health and Disease Cohort, enterolactone concentrations were measured by time-resolved fluoroimmunoassay in plasma taken from 265 men who were diagnosed with prostate cancer at a mean time of 5 years after blood collection, and in plasma from 525 control men, matched for age and date of blood collection. RESULTS: There was no significant association between quartiles of plasma enterolactone and risk of prostate cancer. Odds ratios for prostate cancer, estimated by conditional logistic regression for increasing concentrations of enterolactone in quartiles were 1.00 (referent), 0.81 (95% confidence interval 0.52-1.27), 1.03 (0.67-1.58), and 1.22 (0.80-1.86). Adjustments for body mass index (BMI), smoking status and stratification for age, lag time, storage time and tumour characteristics did not materially alter risk estimates. Men with very low enterolactone levels, however, had significantly higher risk of prostate cancer, odds ratio for bottom decile versus all other deciles was 1.68 (1.03-2.74). CONCLUSIONS: Our results do not support the hypothesis that enterolactone formed from dietary lignans protects against prostate cancer.

Percent Gleason grade 4/5 as prognostic factor in prostate cancer diagnosed at transurethral resection.

PURPOSE: We investigated the value of percent Gleason grade 4/5 as a predictor of long-term outcome in men with prostate cancer diagnosed at transurethral resection who received deferred treatment. MATERIALS AND METHODS: A series of 305 men with prostate cancer diagnosed at transurethral resection from 1975 to 1990 who had subsequent expectancy was analyzed. Mean patient age at diagnosis was 74 years (range 52 to 95). Slides were reviewed, and the Gleason score, percent Gleason grade 4/5 and modified Gleason score (the sum of the dominant and worst grades) were assessed. RESULTS: At followup 271 men (89%) had died, including 110 (36%) of prostate cancer. Gleason score, percent Gleason grade 4/5 and modified Gleason score were significant predictors of disease specific survival (p <0.001). Of all men 34% had tumors without any grade 4/5 pattern, of whom only 8% died of prostate cancer compared with 52% with any grade 4/5 pattern (p <0.001). Gleason score 6 tumors with focal grade 4 (less than 5%) had a worse prognosis than pure Gleason score 3 + 3 = 6 tumors (p = 0.008). There was nonsignificantly shorter survival for Gleason score 4 + 3 = 7 than for Gleason score 3 + 4 = 7 disease (p = 0.19). In Cox models including all possible pairs of Gleason score, percent Gleason grade 4/5 and modified Gleason score the percent Gleason grade 4/5 and modified Gleason score were stronger than Gleason score, although all 3 were independently significant prognosticators. CONCLUSIONS: Percent Gleason grade 4/5, modified Gleason score and Gleason score are predictors of disease specific survival in patients with prostate cancer on deferred treatment. Our study indicates that any grade 4/5 pattern impairs the prognosis significantly.