Medical history and etiology of prostate cancer

miR-1266-5p and miR-185-5p Promote Cell Apoptosis in Human Prostate Cancer Cell Lines

Objective:

Small non-coding RNA molecules are dysregulated in prostate cancer (PCa). In our previous study, downregulation of miR-1266 and miR-185 was demonstrated in PCa tissues and cell lines. The aim of the present study was to investigate whether miR-1266 and miR-185 are involved in the regulation of B-cell lymphoma (BCL) 2 and BCL2L1, respectively, and whether transfection of PCa cell lines with miR-1266 and miR-185 mimics can alter tumorigenic phenotypes.

Methods:

In order to investigate the regulation of BCL2 and BCL2L1 mRNA levels by miR-1266 and miR-185, respectively, a luciferase reporter assay was used. Real-time PCR was also used to analyze changes in the levels of BCL2 and BCL2L1 mRNAs in PCa cell lines following transfection with synthetic miR-1266 and miR-185. Cell apoptosis was determined by Annexin V protein expression analysis via flow cytometry. In addition to the MTT assay, a cell proliferation assay was performed.

Result:

A luciferase assay confirmed that the BCL2 and BCL2L1 genes may be targeted by miR-1266 and miR-185, respectively, through binding to their 3′UTR regions. Transfection of PC3 and DU145 cells with miR-1266 and miR-185 induced apoptosis and reduced proliferation, which also revealed an inverse correlation with BCL2 and BCL2L1 gene expression in the treated cells.

Conclusion:

Our data suggests that miR-1266 and miR-185 may be novel candidates for further research in PCa treatment through the anti-apoptotic pathway.

An Interleukin-6 Single Nucleotide Polymorphism and Susceptibility to Prostate Adenocarcinoma and Bone Metastasis in an Iranian Population

Objective:

Interleukin-6 (IL-6) is an inflammatory cytokine shown to be a strong factor for growth, proliferation and metastasis with many malignancies. The promoter single nucleotide polymorphism (SNPs) -174G>C (rs1800795) can alter the transcriptional pattern of this gene. The present study was aimed at assessing effects of the IL-6 (rs1800795) SNP on risk of benign prostate hyperplasia (BPH) and prostatic adenocarcinoma (PCa).

Methods:

The project was performed on 112 men with PCa, 118 with BPH and 250 healthy controls. After DNA extraction, genotyping of IL-6 (rs1800795) was performed using PCR TaqMan Allelic Discrimination (ABI MGB).

Results:

The G allele frequency for rs1800795 of the IL-6 gene was 74.1%, 68.6% and 67% in PCa patients, BPH patients and healthy men, respectively. PCa and control groups showed significant differences (P =0.030, OR = 1.73, 95% CI: 1.05-2.21). The GG genotype was more frequent in the PCa group, whereas the GC genotype was more common in the BPH in comparison to other groups.

Conclusion:

The current study identified IL-6 -174G>C (rs1800795) as a significant predictor of susceptibility for prostate cancer and bone metastasis in a northwest Iranian population.

Downregulation of miR-1266-5P, miR-185-5P and miR-30c-2 in prostatic cancer tissue and cell lines

Over the latest decade, the role of microRNAs (miRNAs/miRs) has received more attention. miRNAs are small non-coding RNAs that may serve a role as oncogenes or tumor suppressor genes. Certain miRNAs regulate the apoptosis pathway by influencing pro- or anti-apoptotic genes. We hypothesized that increases in the expression of B cell lymphoma 2 (BCL2) and BCL2-like 1 (BCL2L1) genes, which have been reported in various types of cancer tissues, may be due to the downregulation of certain miRNAs. The present study aimed to identify miRNAs that target BCL2 and BCL2L1 anti-apoptotic genes in prostate cancer (PCa) clinical tissue samples. Certain candidate miRNAs were selected bioinformatically and their expression in PCa samples was analyzed and compared with that in benign prostatic hyperplasia (BPH) tissue samples. The candidate miRNAs that targeted BCL2 and BCL2L1 genes were searched in online databases (miRWalk, microRNA.org, miRDB and TargetScan). A total of 12 miRNAs that target the 3'-untranslated region of the aforementioned genes and/or for which downregulation of their expression has previously been reported in cancer tissues. A total of 30 tumor tissue samples from patients with PCa and 30 samples tissues from patients with BPH were obtained and were subjected to reverse transcription-quantitative polymerase chain reaction for expression analysis of 12 candidate miRNAs, and the BCL2 and BCL2L1 genes. Additionally, expression of 3 finally selected miRNAs and genes was evaluated in prostate cancer PC3 and DU145 cell lines and human umbilical vein endothelial cells. Among 12 miRNA candidates, the expression of miR-1266, miR-185 and miR-30c-2 was markedly downregulated in PCa tumor tissues and cell lines. Furthermore, downregulation of these miRNAs was associated with upregulation of the BCL2 and BCL2L1 genes. An inverse association between three miRNAs (miR-1266, miR-185 and miR-30c-2) and two anti-apoptotic genes (BCL2 and BCL2L1) may be considered for interventional miRNA therapy of PCa.

The clinical course of alcoholic cirrhosis: development of comorbid diseases. A Danish nationwide cohort study

BACKGROUND & AIMS

We aimed to determine associations between alcoholic cirrhosis and incidence of comorbidity, and to describe the clinical course of alcoholic cirrhosis in terms of comorbidity development. The comorbid diseases we studied were acute myocardial infarction, heart failure, peripheral arterial disease, chronic obstructive pulmonary disease, chronic kidney disease, epilepsy, diabetes and cancer.

METHODS

This was a registry-based nationwide historical cohort study. We included 10 650 Danish citizens diagnosed with alcoholic cirrhosis at age 45-69 years in 1994-2014 and 43 150 age- and gender-matched persons. None of them had the comorbid diseases we studied at inclusion. We compared rates and cumulative risks of comorbidity development between patients and controls.

RESULTS

Patients with alcoholic cirrhosis had a higher rate of comorbidity (hazard ratio for any comorbidity = 3.74, 95% CI 3.56-3.94), including all the non-cancer comorbidities (hazard ratio for any non-cancer comorbidity = 4.33, 95% CI 4.06-4.62) except acute myocardial infarction. They also had a higher rate of developing cancer (hazard ratio = 2.94, 95% CI 2.70-3.19). Still, relatively few patients actually lived to experience development of non-cancer (10-year risk: 21.4% vs. 13.2% for controls) or cancer comorbidity (10-year risk: 10.9% vs. 10.0%) because they died before they developed any comorbid disease. Hepatocellular carcinoma and oropharyngeal cancer were the only two comorbidities that were much more likely to develop in patients than in controls.

CONCLUSIONS

Alcoholic cirrhosis promotes development of several comorbid diseases, but only few patients with alcoholic cirrhosis live long enough to actually develop them.

Pseudomonas aeruginosa biofilm infections: from molecular biofilm biology to new treatment possibilities

Bacteria in natural, industrial and clinical settings predominantly live in biofilms, i.e., sessile structured microbial communities encased in self-produced extracellular matrix material. One of the most important characteristics of microbial biofilms is that the resident bacteria display a remarkable increased tolerance toward antimicrobial attack. Biofilms formed by opportunistic pathogenic bacteria are involved in devastating persistent medical device-associated infections, and chronic infections in individuals who are immune-compromised or otherwise impaired in the host defense. Because the use of conventional antimicrobial compounds in many cases cannot eradicate biofilms, there is an urgent need to develop alternative measures to combat biofilm infections. The present review is focussed on the important opportunistic pathogen and biofilm model organism Pseudomonas aeruginosa. Initially, biofilm infections where P. aeruginosa plays an important role are described. Subsequently, current insights into the molecular mechanisms involved in P. aeruginosa biofilm formation and the associated antimicrobial tolerance are reviewed. And finally, based on our knowledge about molecular biofilm biology, a number of therapeutic strategies for combat of P. aeruginosa biofilm infections are presented.

Ca2+ clearance mechanisms in cancer cell lines and stromal cells of the prostate

BACKGROUND

Three prostatic cell lines, PC3, LNCaP, and DU 145, are used as established models to study cell signaling in prostate cancer. Recently, stromal cell lines of the prostate, such as P21, were also introduced. Here we investigate a basic and important mechanism of living cells: Ca(2+) homeostasis in PC3, DU 145, and P21.

METHODS

We examined Ca(2+) clearance mechanisms by monitoring the kinetics of recovery from histamine stimulation under conditions which inhibit prospect mechanisms for storing or extrusion of Ca(2+) from the cytosol by photometry.

RESULTS

Despite the fact that in all three cell lines the Ca(2+) ATPase of the plasma membrane and the SERCA are most important for Ca(2+) homeostasis, inhibition of PMCA in epithelial cells has a greater effect than in stromal cells. Furthermore, the proportion of PMCA and SERCA differs in PC3 and DU145 cells. PMCA is most effective at reaching resting [Ca(2+) ]i in the final recovery stage. In contrast to DU 145 and P21 cells, PC3 are the only cells substantially affected by the inhibition of the mitochondrial uniporter. In all cell lines the role of the sodium calcium exchanger is marginal.

CONCLUSION

These results demonstrate that not only cancer and stromal cell lines show significant differences in the modes and extent of their use of Ca(2+) clearance mechanisms, but also the cancer cell lines themselves.

The role of inflammatory mediators in the development of prostatic hyperplasia and prostate cancer

Benign prostatic hyperplasia and prostate cancer remain the most prevalent urologic health concerns affecting elderly men in their lifetime. Only 20% of benign prostatic hyperplasia and prostate cancer cases coexist in the same zone of the prostate and require a long time for initiation and progression. While the pathogenesis of both diseases is not fully understood, benign prostatic hyperplasia and prostate cancer are thought to have a multifactorial etiology, their incidence and prevalence are indeed affected by age and hormones, and they are associated with chronic prostatic inflammation. At least 20% of all human malignancies arise in a tissue microenvironment dominated by chronic or recurrent inflammation. In prostate malignancy, chronic inflammation is an extremely common histopathologic finding; its origin remains a subject of debate and may in fact be multifactorial. Emerging insights suggest that prostate epithelium damage potentially inflicted by multiple environmental factors such as infectious agents, dietary carcinogens, and hormones triggers procarcinogenic inflammatory processes and promotes cell transformation and disease development. Also, the coincidence of chronic inflammation and tumorigenesis in the peripheral zone has recently been linked by studies identifying so-called proliferative inflammatory atrophy as a possible precursor of prostatic intraepithelial neoplasia and prostate cancer. This paper will discuss the available evidence suggesting that chronic inflammation may be involved in the development and progression of chronic prostatic disease, although a direct causal role for chronic inflammation or infection in prostatic carcinogenesis has yet to be established in humans. Further basic and clinical research in the area, trying to understand the etiology of prostatic inflammation and its signaling pathway may help to identify new therapeutic targets and novel preventive strategies for reducing the risk of developing benign and malignant tumors of the prostate.

Inflammation and prostate carcinogenesis

Quite a few epidemiological studies including meta-analyses indicate that prostate inflammation is associated with increased risk of prostate cancer. The cause of inflammation in the prostate is speculated to be several microorganisms that cause prostatitis or sexually transmitted infections. Other specific microorganisms, such as xenotropic murine leukemia virus-related virus, are also reported to relate to the development of prostate cancer; however, the contribution of this microorganism to prostate cancer development needs to be carefully interpreted. Environmental factors, especially dietary factors, might also be associated with prostate cancer development. Among related dietary factors, charred meat carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine might be a link between environmental factors and inflammation, because 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine has the potential to accelerate prostate inflammation through its estrogenic effect. In light of these findings, preventing or reducing prostate inflammation might be one strategy for chemoprevention of prostate cancer.

The metabolic syndrome and risk of prostate cancer in Italy

PURPOSE

To provide information on the role of the metabolic syndrome on prostate cancer risk.

METHODS

We examined data from a multicentric Italian case-control study. Cases were 1294 patients with incident, histologically confirmed prostate cancer. Controls were 1451 men hospitalized with acute, non-neoplastic conditions. All subjects were younger than 75 years. The metabolic syndrome was defined according to selected indicators of abdominal obesity, hypercholesterolemia, hypertension, and diabetes. We computed multivariate odds ratios (OR) and 95% confidence intervals (CI) using unconditional logistic regression.

RESULTS

Considering separate components of the metabolic syndrome, the ORs were 0.98 (95% CI, 0.72-1.34) for diabetes, 1.14 (95% CI, 0.96-1.36) for hypertension, 1.54 (95% CI, 1.26-1.89) for hypercholesterolemia, and 1.02 (95% CI, 0.86-1.21) for abdominal obesity. The OR of prostate cancer was 1.66 (95% CI, 1.22-2.28) in men with metabolic syndrome compared with those without. We found ORs of 1.02 (95% CI, 0.83-1.26) for men with one component of the metabolic syndrome, 1.12 (95% CI, 0.89-1.42) for two, 1.65 (95% CI, 1.15-2.36) for three, and 3.99 (95% CI, 1.03-15.4) for four compared with no components.

CONCLUSIONS

The metabolic syndrome was associated with the risk of prostate cancer in this population.

Individualized decision-making for older men with prostate cancer: balancing cancer control with treatment consequences across the clinical spectrum

Prostate cancer (PCa) is the most prevalent non-skin cancer among men and is the second leading cause of cancer death in men. PCa has an increased incidence and prevalence in older men. Age-associated incidence is on the rise due to increased screening in the older population. This has led to a sharp rise in the detection of early stage PCa. Given the indolent nature of many prostatic malignancies, a large proportion of older men with PCa will ultimately die from other causes. As a result, physicians and patients are faced with the challenge of identifying optimal treatment strategies for localized PCa, biochemically recurrent PCa and later-stage PCa. Age-related changes can impact tolerance of hormonal therapy and chemotherapy in men with metastatic disease and shift the risk-benefit ratio of these treatments. Tools such as the Comprehensive Geriatric Assessment (CGA) can help estimate remaining life expectancy and can help predict treatment-related morbidity and mortality in older men. Application of CGA in older men with PCa is important to help individualize and optimize treatment strategies. Research that integrates multidisciplinary and multidimensional assessment of PCa and the patient's overall health status is needed.

High-dose dietary zinc promotes prostate intraepithelial neoplasia in a murine tumor induction model

To evaluate the role of high-dose dietary zinc in the process of prostate malignancy, 60 Sprague-Dawley rats were randomly divided into four groups: tumor induction with carcinogen and hormone (group 1), oral zinc administration without tumor induction (group 2), oral zinc administration with tumor induction (group 3) and a control without zinc administration or tumor induction (group 4). Zinc was supplied orally in the form of zinc sulfate heptahydrate dissolved in drinking water to groups 2 and 3 for 20 weeks. Although the serum level of zinc measured at 20 weeks was maintained similarly in each group (P = 0.082), intraprostatic zinc concentrations were statistically different. Group 1 prostates contained the least amount of zinc in both the dorsolateral and ventral lobes at levels of 36.3 and 4.8 microg g(-1), respectively. However, in group 3, zinc levels increased in both lobes to 59.3 and 12.1 microg g(-1), respectively, comparable with that of group 4 (54.5 +/- 14.6 and 14.1 +/- 2.4 microg g(-1)). In spite of these increases in zinc concentration, the prevalence of prostate intraepithelial neoplasm was rather increased in group 3 (53.3% and 46.7%) compared with group 1 (33.3% and 33.3%) in both dorsolateral and ventral prostate lobes. Although prostate intraepithelial neoplasm did not develop in any prostate in group 4, zinc administration did induce prostate intraepithelial neoplasm in group 2 (46.7% and 40.0%). Thus, although high dietary zinc increased intraprostatic zinc concentrations, it promoted, instead of preventing, prostate intraepithelial neoplasm in a murine prostate malignancy induction model.

Chronic bacterial inflammation induces prostatic intraepithelial neoplasia in mouse prostate

Background:

Although the aetiology of prostate cancer remains unknown, we hypothesised that chronic bacterial insult has a major role in prostate carcinogenesis.

Methods:

Male C3H/HeOuJ mice, infected with phosphate-buffered saline or Escherichia coli bacteria, were killed at 5 days, or at 12 or 26 weeks. Harvested prostate tissues were evaluated for inflammatory responses and immunostained for neoplastic transformation markers.

Results:

All infected mice developed bacterial prostatitis. Control mice had no prostate infections or inflammation. Mice infected for 5 days showed foci of acute inflammation with infiltrating neutrophils and epithelial necrotic debris in the prostatic glandular lumen. All mice infected for 12 weeks had evidence of chronic inflammation with dense inflammatory infiltrates in the stroma. The prostatic epithelium showed varying degrees of atypical hyperplasia with increased epithelial cell layers and cytological atypia. At 26 weeks, the dysplastic changes were more pronounced and mimicked a prostatic intraepithelial neoplasia and high-grade dysplasia. Prostatic glands exhibiting reactive dysplasia had a stronger staining for oxidative DNA damage, increased epithelial cell proliferation, and a decrease in androgen receptor, GSTP1, p27^Kip1, and PTEN expression, when compared with control prostate glands.

Conclusion:

These data demonstrate that chronic inflammation induces focal prostatic glandular atypia and suggest a potential linkage between inflammation and prostatic neoplasia.

Medical history, body size, and cigarette smoking in relation to fatal prostate cancer

OBJECTIVES

Prostate cancer has few known risk factors. As part of a population-based case-control study conducted in four health maintenance organizations, the authors examined the associations between fatal prostate cancer and several medical and behavioral characteristics.

METHODS

Cases were 768 health plan members who died of prostate adenocarcinoma during the period 1997-2001. We randomly selected controls (929) from the health plan membership and matched them to cases on health plan, age, race, and pattern of health plan membership. We examined medical records to obtain information on potential risk factors during the 10 years before the date on which prostate cancer was first suspected; the same reference date was used for the matched controls.

RESULTS

Anthropometric characteristics, as well as personal histories of benign prostatic hypertrophy, transurethral prostatectomy, cancer, diabetes, prostatitis, hypertension, and vasectomy were largely similar for cases and controls. Men who died from prostate cancer were more likely than controls to have been cigarette smokers according to the most recent smoking notation before the reference date (odds ratio 1.5, 95% confidence interval 1.1-2.0).

CONCLUSIONS

The observed increase in risk associated with recent cigarette smoking is consistent with the findings of several other studies. However, in contrast with some reports, we observed no connection between fatal prostate cancer and some prior health conditions or measures of body size.

Sexually transmitted infections and prostate cancer among men in the U.S. military

Studies of self-reported sexually transmitted infections (STI) suggesting an association with prostate cancer may reflect underreporting of such infections among nondiseased subjects. To reduce such bias, we studied archived sera in a cohort of U.S. military personnel known to have high rates of both STIs and prostate cancer. Using a nested case-control design, serum samples from 534 men who served on active duty between September 1, 1993 and September 1, 2003 were examined. Controls were individually matched to cases based on date of serum collection, date of birth, branch of service, military rank, marital status, and race. Each of the 267 case-control pairs had two serum samples: a recent serum sample, taken approximately 1 year before the case's prostate cancer diagnosis, and an earlier serum sample, taken approximately 8 years before diagnosis. Each serum specimen was studied for antibodies against human papillomavirus, herpes simplex virus-2 (HSV-2), and Chlamydia trachomatis. Logistic regression accounted for matching and potential confounding factors. Study data indicated no association between prostate cancer and serologic evidence of infections just before the reference date. However, a statistically significant association between prostate cancer and serologic evidence of HSV-2 infection was detected in the earlier sample (odds ratio, 1.60; 95% confidence interval, 1.05-2.44). The strength of this association increased when analyses were restricted to sera collected at least 60 months before diagnosis (odds ratio, 2.04; 95% confidence interval, 1.26-3.29; 204 pairs). If this association is causal, then our findings would suggest a long latency period for prostate cancer development after HSV-2 infection.

Vasectomy and the risk of prostate cancer

PURPOSE

While the weight of evidence shows no association overall between vasectomy and prostate cancer, there has been some suggestion that an association may exist in subgroups, such as men who have a family history of prostate cancer, men who undergo vasectomy at a younger age or when several decades have passed since the procedure. Studies of risk with long latency periods have been hampered by small sample sizes in subgroups since vasectomy only became widely used in the 1960s and generally prostate cancer has a long latency period.

MATERIALS AND METHODS

We analyzed data from a recent population based case-control study that was designed specifically to address this issue of risk in subgroups. Interviews were completed with 1,001 men diagnosed with prostate cancer from January 1, 2002 through December 31, 2005 in the Seattle-Puget Sound region and in 942 matched control men. Subjects were black and white men between the ages of 35 and 74 years. Data were analyzed using unconditional logistic regression to calculate the OR as an estimate of the relative risk of prostate cancer associated with various vasectomy parameters.

RESULTS

The prevalence of vasectomy was similar in cases and controls (36.2% and 36.1%, respectively, adjusted OR 1.0, 95% CI 0.8-1.2). There were also no associations between prostate cancer and age at vasectomy, years elapsed since vasectomy or calendar year of vasectomy.

CONCLUSIONS

These findings indicate that there is no association between vasectomy and the risk of prostate cancer.

Glycemic status and risk of prostate cancer

BACKGROUND

To examine the risk of prostate cancer and glucose tolerance in a large, racially diverse cohort.

METHODS

We conducted a cohort study of 47,209 male members of Kaiser Permanente Northern California who had completed at least one Multiphasic Health Checkup (MHC) between 1964 and 1973. The MHC provided information on diabetes, serum glucose 1 h after a 75-g oral glucose challenge test, demographics, and other health conditions. Cox proportional hazards were used to estimate relative risks (RR) while adjusting for confounders.

RESULTS

During a median follow-up of 18.4 years, a total of 2,833 men developed prostate cancer. At baseline, 4.6% (n = 2,159) of the cohort had diabetes and 33% had serum glucose of >or=200 mg/dL. After adjusting for age, race, birth year, and body mass index, RR (95% confidence interval) of prostate cancer associated with 1-h serum glucose >or=200 mg/dL and diabetes were 0.90 (0.81-1.01) and 0.71 (0.62-0.79), respectively, when compared with those with serum glucose <140 mg/dL. During the first 10 years of follow-up, risk was increased among those with serum glucose >or=200 mg/dL or diabetes [RR (95% confidence interval), 1.42 (0.95-2.13) and 1.56 (0.91-2.67), respectively]. In contrast, inverse associations between serum glucose >or=200 mg/dL and diabetes and prostate cancer risk were observed [0.87 (0.77-0.97) and 0.68 (0.52-0.88), respectively] when follow-up began 10 years after MHC.

CONCLUSION

Our findings are consistent with the hypothesis that prostate cancer risk differs by time since diabetes diagnosis or occurrence of metabolic aberrations associated with impaired glucose tolerance.

LNCaP prostate cancer cells are insensitive to zinc-induced senescence

Prostate cancer is an age-related disease that is linked to the inability of prostate cells to accumulate zinc following transformation. It is shown in the present study that the basal percentage of normal prostate cells expressing senescence-associated beta-galactosidase (SA-beta-gal) is higher than that of the cancer cells. In the presence of high zinc in the cell culture medium, the percentage of normal prostate cells expressing the SA-beta-gal increased but not that of the cancer cells. Increased intracellular zinc occurs in the prostate cancer cells treated with supraphysiologic concentration of zinc but it does not induce senescence or decrease the telomerase activities in these cells. Senescence, however, occurred when the prostate cancer cells DNA is damaged by irradiation. These findings suggest that prostate cancer cells are insensitive to the senescence-inducing effects of zinc but the cancer cells retain the capacity to undergo senescence through other pathways.

Association of extent and aggressiveness of inflammation with serum PSA levels and PSA density in asymptomatic patients

OBJECTIVES

The relationship between serum prostate-specific antigen (PSA) levels and histologic prostatic inflammation is controversial. Previous studies were performed using either the intensity or extent of inflammation for grading, with a relatively lower number of specimens. In our study, the inflammation was categorized more profoundly, using both the intensity and the extent of inflammation, to determine the influence of prostatic inflammation on serum PSA levels, percent free PSA (%fPSA), and PSA density (PSAD).

METHODS

The study included 115 patients who underwent transrectal ultrasound-guided prostate biopsy. To categorize the inflammation, a grading method that included the intensity and extent of inflammation was used. The extent and aggressiveness of inflammation were analyzed. The patients were divided into groups using five grades for the extent and four grades for the aggressiveness of inflammation. The serum PSA levels, fPSA levels, %fPSA, and PSAD in each group were compared.

RESULTS

The extent of inflammation grade correlated positively with the serum PSA level (r = 0.423, P <0.001) and PSAD (r = 0.319, P = 0.001). However, a negative correlation was found between the extent of inflammation grade and %fPSA (r = -0.268, P = 0.015). The aggressiveness of inflammation grade correlated positively with the serum PSA level (r = 0.386, P <0.001) and PSAD (r = 0.341, P = 0.001) and negatively with %fPSA (r = -0.289, P = 0.03).

CONCLUSIONS

If the elevation of serum PSA is thought to be caused by histologic inflammation, it might prevent unnecessary repeated biopsies.

Obesity, metabolic syndrome, and prostate cancer

Although obesity has been consistently linked to an increased risk of several malignancies, including cancers of the colon, gallbladder, kidney, and pancreas, its role in prostate cancer etiology remains elusive. Data on the association between obesity and prostate cancer incidence are inconsistent, and in some studies obesity is associated with an increase in risk of high-grade prostate cancer but with a decrease in risk of low-grade tumors. In contrast, obesity has been consistently associated with an increased risk of prostate cancer aggressiveness and mortality. The differential effects of obesity on subtypes of prostate cancer suggest etiologic heterogeneity in these tumors and complex interactions between androgen metabolism and several putative risk factors, including insulin resistance, diabetes, inflammation, and genetic susceptibility, on prostate cancer risk. Data on the role of abdominal obesity, insulin resistance, and metabolic syndrome in prostate cancer etiology are limited. Obesity has been shown to be associated with a state of low-grade chronic inflammation, and insulin resistance and the metabolic syndrome are associated with adverse metabolic profiles and with higher circulating concentrations of inflammation-related markers, including leptin, interleukin-6, and tumor necrosis factor-, many of which have been shown to enhance tumor growth. Thus, whether obesity and metabolic syndrome modulate the risk of prostate cancer through chronic inflammation needs to be investigated further. Given that the prevalence of obesity and metabolic syndrome is increasing worldwide and that the world population is aging, the roles of obesity and metabolic syndrome in prostate carcinogenesis warrant further clarification.

Adoption of a plant-based diet by patients with recurrent prostate cancer

The Western diet has been associated with prostate cancer incidence as well as risk of disease progression after treatment. Conversely, plant-based diets have been associated with decreased risks. A pilot clinical trial of a 6-month dietary change and stress reduction intervention for asymptomatic, hormonally untreated patients experiencing a consistently rising PSA level, the first sign of recurrence of prostate cancer after surgery or radiation therapy, was conducted to investigate the level of intake of plant-based foods and the relationship between intake and the change in the rate of PSA rise. A pre-post design was employed in which each patient served as his own control. In this multifaceted intervention, patients and their spouses were encouraged to adopt and maintain a plant-based diet. The prestudy rate of PSA rise (from the time of posttreatment recurrence to the start of the study) was ascertained by review of patients' medical records. Dietary assessments were performed and prostate-specific antigen (PSA) levels ascertained at baseline, prior to the start of intervention, and at 3 and 6 months. Changes in numbers of servings of plant-based food groups were calculated and compared with rates of PSA rise over the corresponding time intervals. Median intake of whole grains increased from 1.7 servings/d at baseline to 6.9 and 5.0 servings/d at 3 and 6 months, respectively. Median intake of vegetables increased from 2.8 servings/d at baseline to 5.0 and 4.8 servings/d at 3 and 6 months, respectively. The rate of PSA rise decreased when comparing the prestudy period (0.059) to the period from 0 to 3 months (-0.002, P < .01) and increased slightly, though not significantly, when comparing the period from 0 to 3 months to the period from 3 to 6 months (0.029, P = .4316). These results provide preliminary evidence that adoption of a plant-based diet is possible to achieve as well as to maintain for several months in patients with recurrent prostate cancer. Changes in the rate of rise in PSA, an indicator of disease progression, were in the opposite direction as changes in the intake of plant-based food groups, raising the provocative possibility that PSA may have inversely tracked intake of these foods and suggesting that adoption of a plant-based diet may have therapeutic potential in the management of this condition.

Molecular pathology of prostate cancer

The molecular pathology of prostate cancer is complex; not only are multiple genes involved in its pathogenesis, but additional environmental factors such as diet and inflammation are also involved. The exhaustive research into prostate cancer to date has demonstrated a complex interaction of multiple genes and environmental factors, some of which may be more important in individual prostate cancer cases. This is an exciting era, with the emergence of new investigative tools such as DNA microarray technology and the application of the field of proteomics to the study of human cancers. Knowledge of genetic changes underlying the initiation, development, and progression of prostate cancer is accumulating rapidly. With increasing knowledge, it may be possible to distinguish indolent from aggressive prostate tumours by molecular fingerprinting. This review discusses the most consistently reported molecular pathological findings in hereditary and sporadic prostate cancer, together with new concepts and technologies.

Sexually transmitted diseases and other urogenital conditions as risk factors for prostate cancer: a case–control study in Wayne County, Michigan

OBJECTIVE To investigate associations between prostate cancer and sexually transmitted diseases (STDs), prostatitis, benign prostatic hyperplasia (BPH), and vasectomy in a population-based case-control study in Wayne County, Michigan, among African American and white men aged 50--74 years.

METHODS

Incident prostate cancer cases (n=700) from 1996--1998 were identified from the Metropolitan Detroit Cancer Surveillance System. Controls (n=604) were identified through random digit dialing and Medicare recipient lists, and frequency matched to cases on age and race. History of potential prostate cancer risk factors was ascertained through in-person interview.

RESULTS

Prostate cancer was not associated with STD or vasectomy history. History of prostatitis was associated with prostate cancer among all subjects (odds ratio [OR]=1.8, 95% confidence interval [CI]: 1.1, 2.9) and in African American men (OR=2.2, 95% CI: 1.1, 4.6). History of BPH was associated with prostate cancer among all subjects (OR=2.4, 95% CI: 1.8, 3.3); significant associations were observed in both African American (OR=2.7, 95% CI: 1.6, 4.4) and white (OR=2.3, 95% CI: 1.5, 3.4) men.

CONCLUSIONS

Among all subjects, prostate cancer was associated with prostatitis and BPH history, but not with STD or vasectomy history. Prevention efforts could be enhanced if inflammatory or infectious etiologies are found to be of importance in the subsequent development of prostate cancer.

Diabetes Mellitus and the Risk of Prostate Cancer in Italy

OBJECTIVE

We investigated the relation between diabetes and the risk of prostate cancer, as epidemiological results are controversial.

METHODS

A hospital-based case-control study was conducted in Italy between 1991 and 2002. Cases were 1294 men, aged <75 years, with incident histologically confirmed prostate cancer, and controls were 1451 men, aged <75 years, admitted to hospital for acute non-neoplastic diseases. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated using unconditional multiple logistic regression models.

RESULTS

No material association between diabetes and prostate cancer was observed, with a multivariate OR of 1.02 (95%CI 0.75-1.40). Prostate cancer was not related to time since diagnosis of diabetes (OR 0.82 and 0.97 for <5 and >/=15 years since diagnosis respectively). The OR were respectively 1.63 (95%CI 0.70-3.81) and 0.96 (95%CI 0.68-1.34) in men diagnosed with diabetes at age <45 or >/=45 years. The risk estimates were similar across strata of age at interview, body mass index and, among cases, of Gleason score.

CONCLUSIONS

This study shows no material association between diabetes and prostate cancer risk.

Soy protein isolates of varying isoflavone content exert minor effects on serum reproductive hormones in healthy young men

Inverse associations between soy and prostate cancer and the contribution of hormones to prostate cancer prompted the current study to determine whether soy protein could alter serum hormones in men. Thirty-five men consumed milk protein isolate (MPI), low-isoflavone soy protein isolate (SPI) (low-iso SPI; 1.64 +/- 0.19 mg isoflavones/d), and high-iso SPI (61.7 +/- 7.35 mg isoflavones/d) for 57 d each in a randomized crossover design. Twenty-four-hour urine samples indicated that urinary isoflavones were significantly increased by the high-iso SPI relative to the low-iso SPI and MPI. Serum collected on d 1, 29, and 57 of each treatment revealed that dihydrotestosterone (DHT) and DHT/testosterone were significantly decreased by the low-iso SPI [9.4% (P = 0.036) and 9.0% (P = 0.004), respectively] and the high-iso SPI [15% (P = 0.047) and 14% (P = 0.013), respectively], compared with the MPI at d 57. Other significant effects included a decrease in testosterone by the low-iso SPI relative to the MPI (P = 0.023) and high-iso SPI (P = 0.020) at d 29; an increase in dehydroepiandrosterone sulfate by the low-iso SPI relative to the MPI at d 29 (P = 0.001) and relative to the MPI (P = 0.0003) and high-iso SPI (P = 0.005) at d 57; and increases in estradiol and estrone by the low-iso SPI relative to the MPI at d 57 (P = 0.010 and P = 0.005, respectively). In conclusion, soy protein, regardless of isoflavone content, decreased DHT and DHT/testosterone with minor effects on other hormones, providing evidence for some effects of soy protein on hormones. The relevance of the magnitude of these effects to future prostate cancer risk requires further investigation.

Medical history, sexual, and maturational factors and prostate cancer risk

PURPOSE

Sexual, physical, and medical factors were investigated in a case-control study of prostate cancer.

METHODS

This population-based study, conducted from 1995 to 1999 in northeastern Ontario, used cancer registry-identified cases (n=760), aged 45 to 84 years, diagnosed between 1995 and 1998. Age-frequency matched controls (n=1632) were obtained from telephone listings. Two separate logistic regression analyses considered: 1) sexual and physical; and 2) medical factors.

RESULTS

For the sexual-physical model, marital status, family income, maximum height, number of marriages, having children, age at first marriage, birth, and needing to shave, and acne were not significantly related to risk. In the medical model, a family history of prostate cancer (OR, 2.99; 95% CI, 2.21-4.04) and history of venereal disease (OR, 2.12; 95% CI, 1.27-3.53) were associated with significantly increased risk. A history of allergies (OR, 0.78; 95% CI, 0.60-1.00), benign prostatic hyperplasia (OR, 0.63; 95% CI, 0.49-0.81), and an annual physical exam (OR, 0.43; 95% CI, 0.21-0.85) were associated with reduced risk. Other factors considered in the medical conditions model, body mass index, smoking non-filter cigarettes, and family income were not associated with prostate cancer.

CONCLUSIONS

This study is consistent with other studies that suggest that infectious agents may be involved in prostate cancer development.

Carbohydrates and the Risk of Breast Cancer among Mexican Women

Objective: High carbohydrate intake has been hypothesized to be a risk factor for breast cancer, possibly mediated by elevated levels of free insulin, estrogens, and insulin-like growth factor-1. Therefore, we conducted a population-based case-control study among a Mexican population characterized by relatively low fat and high carbohydrate intakes. Methods: Women ages 20 to 75 years, identified through six hospitals in Mexico City (n = 475), were interviewed to obtain data relating to diet (using a food frequency questionnaire) and breast cancer risk factors. Controls (n = 1,391) were selected from the Mexico City population using a national sampling frame. Results: Carbohydrate intake was positively associated with breast cancer risk. Compared with women in the lowest quartile of total carbohydrate intake, the relative risk of breast cancer for women in the highest quartile was 2.22 [95% confidence interval (95% CI) 1.63-3.04], adjusting for total energy and potential confounding variables (P for trend &lt; 0.0001). This association was present in premenopausal and postmenopausal women (for highest versus lowest quartile, odds ratio 2.31, 95% CI 1.36-3.91 in premenopausal women and odds ratio 2.22, 95% CI 1.49-3.30 in postmenopausal women). Among carbohydrate components, the strongest associations were observed for sucrose and fructose. No association was observed with total fat intake. Discussion: In this population, a high percentage of calories from carbohydrate, but not from fat, was associated with increased breast cancer risk. This relation deserves to be investigated further, particularly in populations highly susceptible to insulin resistance.

Diabetes mellitus and prostate cancer risk among older men: population-based case-control study

We investigate the relation between diabetes mellitus and risk of prostate cancer among older (age 65–79 years) men in a population-based case–control study of 407 incident histologically confirmed cases registered in the South Carolina Central Cancer Registry between 1999 and 2001 (70.6% response rate); controls were 393 men identified through the Health Care Financing Administration Medicare beneficiary file for South Carolina in 1999 (63.8% response rate). After adjusting for age, race, and prostate cancer screening in the past 5 years, a history of diabetes mellitus was associated with a reduced risk of prostate cancer (adjusted odds ratio (aOR)=0.64; 95% confidence interval (CI)=0.45, 0.91). The protective effect was stronger for those with complications associated with diabetes (aOR=0.61; 95% CI=0.42, 0.90) and for African-American men (aOR=0.36; 95% CI=0.21, 0.62). Additional research is needed to understand the biologic mechanisms by which diabetes may influence prostate cancer risk; genetic factors may play an important role in understanding this association.

Pathological and molecular mechanisms of prostate carcinogenesis: implications for diagnosis, detection, prevention, and treatment

Prostate cancer is an increasing threat throughout the world. As a result of a demographic shift in population, the number of men at risk for developing prostate cancer is growing rapidly. For 2002, an estimated 189,000 prostate cancer cases were diagnosed in the U.S., accompanied by an estimated 30,200 prostate cancer deaths [Jemal et al., 2002]. Most prostate cancer is now diagnosed in men who were biopsied as a result of an elevated serum PSA (>4 ng/ml) level detected following routine screening. Autopsy studies [Breslow et al., 1977; Yatani et al., 1982; Sakr et al., 1993], and the recent results of the Prostate Cancer Prevention Trial (PCPT) [Thompson et al., 2003], a large scale clinical trial where all men entered the trial without an elevated PSA (<3 ng/ml) were subsequently biopsied, indicate the prevalence of histologic prostate cancer is much higher than anticipated by PSA screening. Environmental factors, such as diet and lifestyle, have long been recognized contributors to the development of prostate cancer. Recent studies of the molecular alterations in prostate cancer cells have begun to provide clues as to how prostate cancer may arise and progress. For example, while inflammation in the prostate has been suggested previously as a contributor to prostate cancer development [Gardner and Bennett, 1992; Platz, 1998; De Marzo et al., 1999; Nelson et al., 2003], research regarding the genetic and pathological aspects of prostate inflammation has only recently begun to receive attention. Here, we review the subject of inflammation and prostate cancer as part of a "chronic epithelial injury" hypothesis of prostate carcinogenesis, and the somatic genome and phenotypic changes characteristic of prostate cancer cells. We also present the implications of these changes for prostate cancer diagnosis, detection, prevention, and treatment.

Organochlorines and risk of prostate cancer

This pilot study examined the relationships of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) with prostate cancer. Ninety-nine controls were frequency matched by age in 5-year increments to 58 prostate cancer patients. Thirty PCBs and 18 OCPs were measured in serum by gas chromatography. Multiple logistic regression was used to assess the magnitude of association. Seven organochlorines, dieldrin, p,p'-DDE, trans-nonachlor, oxychlordane, heptachlor epoxide, and PCBs 153 and 180 were detected in at least 20% of all study participants. Adjusting for age, body mass index, and a history of prostatitis, oxychlordane and PCB 180 were associated with an increased risk of prostate cancer. This study suggests that long-term, low-dose exposure to specific OCPs and PCBs in the general population may contribute to an increased risk of prostate cancer and supports further investigation in this area.

Epidemiology of prostatitis: new evidence for a world-wide problem

We review new data on the epidemiology of chronic prostatitis. These population-based studies used reasonable case-definitions to survey various populations from North America, Europe and Asia. Overall, 2-10% of adult men suffer from symptoms compatible with chronic prostatitis at any time and approximately 15% of men suffer from symptoms of prostatitis at some point in their lives. Other epidemiologic data suggest that chronic prostatitis may be associated with an increased risk for development of benign prostatic hyperplasia and prostate cancer. These data suggest that chronic prostatitis is an important international health care problem that merits increased priority from clinicians and researchers.

Epidemiologic association between prostatitis and prostate cancer

OBJECTIVES

To quantify the relationship between prostatitis and prostate cancer by pooling previous epidemiologic studies of this association.

METHODS

A comprehensive search for articles published through 2000 was performed, blinded reviews of each study were conducted, data were abstracted, and all such studies were pooled.

RESULTS

In this meta-analysis, an increased risk was seen among men with a history of prostatitis (odds ratio = 1.6), particularly with population-based case-control studies (odds ratio = 1.8). Increased relative risk estimates were also seen among men with a history of syphilis and a history of gonorrhea.

CONCLUSIONS

These associations with prostate cancer suggest that infections may represent one mechanism through which prostate cancer develops. However, causality is unclear, because recall bias and detection bias cannot be ruled out. Future cohort studies of prostate cancer should examine sexually transmitted infections, as well as other infections, as potential risk factors.