Decreased biochemical progression in patients with castration-resistant prostate cancer using a novel mefenamic acid anti-inflammatory therapy: A randomized controlled trial

Prostate cancer (PCa) is the second most common non-dermatological cancer in men and is a growing public health problem. Castration-resistant disease (CRD) is the most advanced stage of the disease and is difficult to control. Patients with CRD may no longer accept conventional therapies as they are not in appropriate clinical conditions or they refuse to receive it. Given that inflammation is an essential component of CRD origin and progression, anti-inflammatory agents could be a therapeutic option with fenamates as one of the proposed choices. A prospective, randomized, double-blinded, 2-arm, parallel group, phase II-III clinical trial was performed involving 20 patients with CRD-PCa (with a prostate specific antigen level <100 ng/ml) that were undergoing androgen deprivation therapy (ADT) and did not accept any established treatment for that disease stage. In addition to ADT, 10 patients received placebo and 10 received mefenamic acid (500 mg orally every 12 h) for 6 months. The primary endpoint was the change in serum prostate-specific antigen (PSA) at 6 months. The PSA levels decreased significantly with mefenamic acid (an average 42% decrease), whereas there was an average 55% increase in the placebo group (P=0.024). In the patients treated with the placebo, 70% had biochemical disease progression (an increase of ≥25% in PSA levels), which did not occur in any of the patients treated with mefenamic acid (relative risk=0.12; 95% confidence interval, 0.01-0.85; P=0.033). There was a significant increase in quality of life (EQ-5D-5L score) and body mass index (BMI) with the experimental treatment. In conclusion, mefenamic acid administration decreased biochemical progression in patients with castration resistant PCa, improved their quality of life and increased their BMI. Future studies are required in order to strengthen the findings of the present clinical trial. Trial registration, Cuban Public Registry of Clinical Trials Database RPCEC00000248, August 2017.

Potential effect of anti-inflammatory drug use on PSA kinetics and subsequent prostate cancer diagnosis: Risk stratification in black and white men with benign prostate biopsy

BACKGROUND

Rising prostate-specific antigen (PSA) levels are associated with both increased risk of prostate cancer and prostatic inflammation. The confounding effects of inflammation on the utility of PSA kinetics to predict prostate cancer may be partially mitigated by anti-inflammatory drug use. We investigated the influence of anti-inflammatory drug use on the association of PSA kinetics with prostate cancer risk.

METHODS

We studied 488 prostate cancer case-control pairs (290 white, 198 African American (AA)) nested in a retrospective cohort of men with a benign prostate biopsy. A series of multivariable models estimated prostate cancer risk associated with PSA velocity (PSAV) at different levels of anti-inflammatory drug use while adjusting for the presence of both clinical and histologic prostatitis.

RESULTS

In men with one, two, or three or more courses of anti-inflammatory drug use, for each ng/mL/year increase in PSAV, prostate cancer risk increased 1.21-fold, 1.83-fold, and 1.97-fold, respectively ( P < 0.0001). In controls with histologic prostatitis, anti-inflammatory drug use was associated with a significantly lower PSAV ( P < 0.0001). This association was not observed in men with histologic prostatitis who were subsequently diagnosed with prostate cancer. A positive interaction between anti-inflammatory drug use and PSAV-associated prostate cancer risk was only observed in AA men, as well as a strong positive association between any anti-inflammatory drug use and clinical prostatitis ( P = 0.004).

CONCLUSIONS

In men with benign prostate biopsy, accounting for the presence of histologic prostatitis and anti-inflammatory drug use, particularly in AA men, may help distinguish between men with rising PSA because of prostatitis vs undiagnosed cancer.

Role of Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) in Cancer Prevention and Cancer Promotion

The nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed by medical practitioners in many clinical conditions for the symptomatic treatment of pain and fever. Due to their anti-inflammatory properties, these drugs have been investigated for their anticancer effects in numerous studies. This is because chronic inflammation has long been linked to carcinogenesis. As such, anti-inflammatory drugs are believed to play a role in cancer treatment and prevention. In the past few decades, research has shown that NSAIDs may decrease the risk of certain types of cancer. However, there is also a growing body of research that proves the contrary. Furthermore, NSAIDs are well known for many side effects, including some life-threatening ones. This review will discuss the relationship between chronic inflammation and cancer, the role of NSAIDs in cancer prevention and cancer promotion, and some of the potentially lethal side effects of these drugs.

Outcomes of Prostate-specific Antigen-based Prostate Cancer Screening Among Men Using Nonsteroidal Anti-inflammatory Drugs

BACKGROUND

The Finnish Randomized Study of Screening for Prostate Cancer (FinRSPC), the largest component of the European Randomized Study of Screening for Prostate Cancer (ERSPC), showed a smaller, nonsignificant reduction in prostate cancer-specific mortality by systematic prostate-specific antigen (PSA)-based screening compared with the overall ERSPC results. Nonsteroidal anti-inflammatory drugs (NSAIDs) reduce inflammation and also PSA elevations due to intraprostatic inflammation.

OBJECTIVE

To explore whether NSAID usage modifies the effects of PSA-based screening on prostate cancer incidence and mortality.

DESIGN, SETTING, AND PARTICIPANTS

A cohort of 78 165 men from the FinRSPC were linked to a comprehensive national prescription database to obtain information on NSAID reimbursements prior to screening.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Prostate cancer risk and mortality were compared between the FinRSPC screening arm and the control arm among NSAID users and nonusers using an age-adjusted Cox regression model.

RESULTS AND LIMITATIONS

Screening increased the detection of Gleason 6 (hazard ratio [HR] 1.59, 95% confidence interval [CI] 1.47-1.72 and HR 1.39, 95% CI 1.26-1.54) and localized prostate tumors (HR 1.25, 95% CI 1.18-1.32 and HR 1.11, 95% CI 1.03-1.20) more among baseline NSAID nonusers than among users, respectively (p for interaction <0.04 for both). This difference was observed in all three screening rounds. Detection of metastatic prostate cancer was similar in both NSAID users and nonusers. Screening decreased prostate cancer mortality among men using NSAIDs at FinRSPC randomization (HR 0.66, 95% CI 0.49-0.90) but not among nonusers (HR 0.95, 95% CI 0.81-1.12); p for interaction=0.04.

CONCLUSIONS

Screening detected fewer well-differentiated localized tumors among NSAID users than among nonusers. This suggests that PSA screening may cause less overdiagnosis within this subgroup, whereas mortality benefit may be greater among NSAID users.

PATIENT SUMMARY

Prostate cancer screening causes less overdiagnosis of well-differentiated localized prostate tumors among men who use nonsteroidal anti-inflammatory drugs.

Dietary inflammatory index and prostate cancer survival

Systemic inflammatory status has been reported to impact survival of prostate cancer (PCa) patients; however, evidence is lacking on whether the inflammatory potential of diet can influence prognosis of PCa patients. To investigate the association between a dietary inflammatory index (DII) and PCa survival, we conducted a retrospective cohort study including 726 men with PCa originally enrolled, between 1995 and 2002, in an Italian case-control study. Information on diet and Gleason score was collected at PCa diagnosis. DII was derived from a food frequency questionnaire using a validated algorithm. Adjusted hazard ratios (HRs) of death with 95% confidence intervals (CIs) were estimated using a Fine-Gray model. DII scores were not significantly associated with all-cause mortality of PCa patients (HR highest vs. lowest DII tertile = 1.25; 95% CI: 0.86-1.83). However, considerable heterogeneity emerged according to Gleason score (p < 0.01): no associations emerged among men with Gleason score 2-6 PCa; whereas, among patients with Gleason score 7-10 PCa, DII was directly associated with both all-cause and PCa-specific mortality (HR highest vs. lowest DII tertile: 2.78; 95% CI: 1.41-5.48; and 4.01; 95% CI: 1.25-12.86; respectively). Among patients with Gleason score 7-10 PCa, ten-year all-cause survival probabilities were 58% (95% CI: 47-67%) for highest and 78% (95% CI: 67-86%) for lowest DII tertile. Study findings support the hypothesis that diet, through its inflammatory potential, may influence the prognosis of patients with more aggressive PCa. Dietary interventions aimed at decreasing inflammation may be considered to improve survival of men with PCa.

Role of intracellular prostaglandin E₂ in cancer-related phenotypes in PC3 cells

Prostaglandin E2 (PGE2) and hypoxia-inducible factor-1α (HIF-1α) affect many mechanisms that have been shown to play a role in prostate cancer. In PGE2-treated LNCaP cells, up-regulation of HIF-1α requires the internalization of PGE2, which is in sharp contrast with the generally accepted view that PGE2 acts through EP receptors located at the cell membrane. Here we aimed to study in androgen-independent PC3 cells the role of intracellular PGE2 in several events linked to prostate cancer progression. To this end, we used bromocresol green, an inhibitor of prostaglandin uptake that blocked the immediate rise in intracellular immunoreactive PGE2 following treatment with 16,16-dimethyl-PGE2. Bromocresol green prevented the stimulatory effect of 16,16-dimethyl-PGE on cell proliferation, adhesion, migration and invasion and on HIF-1α expression and activity, the latter assessed as the HIF-dependent activation of (i) a hypoxia response element-luciferase plasmid construct, (ii) production of angiogenic factor vascular endothelial growth factor-A and (iii) in vitro angiogenesis. The basal phenotype of PC3 cells was also affected by bromocresol green, that substantially lowered expression of HIF-1α, production of vascular endothelial growth factor-A and cell proliferation. These results, and the fact that we found functional intracellular EP receptors in PC3 cells, suggest that PGE2-dependent intracrine mechanisms play a role in prostate cancer Therefore, inhibition of the prostaglandin uptake transporter might be a novel therapeutic approach for the treatment of prostate cancer.

Do environmental factors modify the genetic risk of prostate cancer?

BACKGROUND

Many SNPs influence prostate cancer risk. To what extent genetic risk can be reduced by environmental factors is unknown.

METHODS

We evaluated effect modification by environmental factors of the association between susceptibility SNPs and prostate cancer in 1,230 incident prostate cancer cases and 1,361 controls, all white and similar ages, nested in the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Trial. Genetic risk scores were calculated as number of risk alleles for 20 validated SNPs. We estimated the association between higher genetic risk (≥12 SNPs) and prostate cancer within environmental factor strata and tested for interaction.

RESULTS

Men with ≥12 risk alleles had 1.98, 2.04, and 1.91 times the odds of total, advanced, and nonadvanced prostate cancer, respectively. These associations were attenuated with the use of selenium supplements, aspirin, ibuprofen, and higher vegetable intake. For selenium, the attenuation was most striking for advanced prostate cancer: compared with <12 alleles and no selenium, the OR for ≥12 alleles was 2.06 [95% confidence interval (CI), 1.67-2.55] in nonusers and 0.99 (0.38-2.58) in users (Pinteraction = 0.031). Aspirin had the most marked attenuation for nonadvanced prostate cancer: compared with <12 alleles and nonusers, the OR for ≥12 alleles was 2.25 (1.69-3.00) in nonusers and 1.70 (1.25-2.32) in users (Pinteraction = 0.009). This pattern was similar for ibuprofen (Pinteraction = 0.023) and vegetables (Pinteraction = 0.010).

CONCLUSIONS

This study suggests that selenium supplements may reduce genetic risk of advanced prostate cancer, whereas aspirin, ibuprofen, and vegetables may reduce genetic risk of nonadvanced prostate cancer.

IMPACT

The effect of genetic factors on prostate cancer risk may vary by lifestyle interventions.

Bone marrow fat: linking adipocyte-induced inflammation with skeletal metastases

Adipocytes are important but underappreciated components of bone marrow microenvironment, and their numbers greatly increase with age, obesity, and associated metabolic pathologies. Age and obesity are also significant risk factors for development of metastatic prostate cancer. Adipocytes are metabolically active cells that secrete adipokines, growth factors, and inflammatory mediators; influence behavior and function of neighboring cells; and have a potential to disturb local milleu and dysregulate normal bone homeostasis. Increased marrow adiposity has been linked to bone marrow inflammation and osteoporosis of the bone, but its effects on growth and progression of prostate tumors that have metastasized to the skeleton are currently not known. This review focuses on fat-bone relationship in a context of normal bone homeostasis and metastatic tumor growth in bone. We discuss effects of marrow fat cells on bone metabolism, hematopoiesis, and inflammation. Special attention is given to CCL2- and COX-2-driven pathways and their potential as therapeutic targets for bone metastatic disease.

Cigarette smoking and prostate cancer risk: negative results of the Seoul Male Cancer Cohort Study

We evaluated cigarette smoking as a risk factor for prostate cancer in a prospective, population-based cohort study. The subjects were 14,450 males among the participants in the Seoul Male Cancer Cohort Study who had at least 1-year follow-up. They were followed up between 1993 and 2008. During the 16-year follow-up period, 87 cases of prostate cancer occurred over the 207,326 person-years of the study. The age-adjusted relative risks of past and current smokers at entry were 0.60 (95%CI: 0.34-1.06) and 0.70 (95%CI: 0.43-1.13), respectively, suggesting that cigarette smoking may not be a risk factor for prostate cancer. The relationship between prostate cancer and other modifiable factors, such as Westernized diet, should be studied with the goal of establishing prevention programs for prostate cancer.

Association of urinary phytoestrogen concentrations with serum concentrations of prostate-specific antigen in the National Health and Nutrition Examination Survey

Some clinical trials have shown that high phytoestrogen intake may decrease serum concentrations of prostate-specific antigen (PSA), and phytoestrogens may also lower prostate cancer risk. It was the aim of this study to examine the relationship between the serum PSA level and urine phytoestrogen concentration in generally healthy U.S. men. Eight hundred twenty-four men, 40+ yr old without prostate cancer, who participated in the 2001-2004 NHANES surveys, were included in the analysis. The association of total PSA, free PSA, and PSA ratio [free PSA/total PSA * 100] with concentrations of isoflavones and lignans (standardized for urinary creatinine concentration) was examined using multivariable-adjusted linear and logistic regression models. The linear regression analyses showed no clear association between creatinine-standardized urinary phytoestrogen concentrations and serum total or free PSA levels or PSA ratio. However, the odds of having a PSA ratio <15% rose from Quartile 1 to Quartile 4 of isoflavone excretion (odds ratio = 2.82, 95% confidence interval 1.28-6.22 for top vs. bottom quartile), but there were no associations with having a PSA ratio <25%. In generally healthy U.S. men, 40+ yr old without a diagnosis of prostate cancer, urinary isoflavone, and lignan concentrations were not associated with serum PSA level.

Screening for prostate cancer: an updated review

Prostate cancer is the most frequently diagnosed malignancy in men and its incidence has been increasing in the last decades. Diagnosis and treatment of prostate cancer were radically improved after the discovery of prostatic-specific antigen. Early detection rates increased, especially in asymptomatic individuals, confirmed by recent published randomized trials. The impact of screening in overdiagnosis and overtreatments is discussed, since benefits in overall mortality rates were not clearly demonstrated. Perhaps younger patients with a longer life expectancy would be the ones with the most benefits from screening. This study presents an update of the most important screening methods for prostate cancer as well as the recent recommendations for screening.

Effects of EPA, γ-linolenic acid or coenzyme Q10 on serum prostate-specific antigen levels: a randomised, double-blind trial

The main objective of the present study was to determine the potential of n-3 and n-6 fatty acids or coenzyme Q10 (CoQ10) to alter serum prostate-specific antigen (PSA) levels in normal healthy men. A total of 504 healthy men with serum PSA level ≤ 2·5 ng/ml were recruited into the study. Serum PSA values were not segregated by decade of age. Participants were randomly assigned to a daily dietary supplement containing n-3 fatty acids (1·12 g of EPA and 0·72 g of DHA per capsule) (group 1, n 126), n-6 fatty acid (600 mg γ-linolenic acid (GLA) each capsule) (group 2, n 126), CoQ10 (100 mg per capsule) (group 3, n 126) or a similar regimen of placebo (group 4, n 126) for 12 weeks. Study medication was administered as two capsules to be taken twice daily. Serum levels of PSA, EPA, DHA, GLA, lipid profile and reproductive hormones were also measured. EPA treatment significantly reduced serum PSA level by 30·0 (95 % CI 25, 36) % (P= 0·004) from baseline. In contrast, GLA therapy significantly increased serum PSA concentration by 15·0 (95 % CI 11, 20) % (P= 0·02). CoQ10 therapy also significantly reduced serum PSA level by 33·0 (95 % CI 27, 40) % (P= 0·002). In multivariable analysis, serum values of PSA were strongly correlated with duration of EPA (r - 0·62; 95 % CI - 0·42, - 0·77; P= 0·003), n-6 (r 0·42; 95 % CI 0·31, 0·58; P= 0·02) and CoQ10 use (r - 0·77; 95 % CI - 0·56, - 0·87; P= 0·001). There were also significant correlations between serum values of DHA, EPA, GLA and CoQ10 and serum PSA levels. The present study demonstrates that dietary supplements containing EPA, GLA or CoQ10 may significantly affect serum PSA levels.

Small molecule tolfenamic acid inhibits PC-3 cell proliferation and invasion in vitro, and tumor growth in orthotopic mouse model for prostate cancer

BACKGROUND

Specificity protein (Sp) transcription factors are implicated in critical cellular and molecular processes associated with cancer that impact tumor growth and metastasis. The non-steroidal anti-inflammatory drug, tolfenamic acid (TA) is known to inhibit Sp proteins in some human cancer cells and laboratory animal models. We evaluated the anti-cancer activity of TA using in vitro and in vivo models for prostate cancer.

METHODS

The anti-proliferative efficacy of TA was evaluated using DU-145, PC-3, and LNCaP cells. PC-3 cells were treated with DMSO or 50 µM TA for 48 hr. Whole cell lysates were evaluated for the expression of Sp1, survivin, c-PARP, Akt/p-Akt, c-Met, cdk4, cdc2, cyclin D3, and E2F1 by Western blot analysis. Cell invasion was assessed by Boyden-chamber assay and flow cytometry analysis was used to study apoptosis and cell cycle distribution. An orthotopic mouse model for prostate cancer with PC-3-Luc cells was used to study the in vivo effect of TA.

RESULTS

TA inhibited the expression of Sp1, c-Met, p-Akt, and survivin; increased c-PARP expression and caspases activity in PC-3 cells. TA caused cell arrest at G(0) /G(1) phase accompanied by a decrease in cdk4, cdc2, cyclin D3, and E2F1 and an increase in critical apoptotic markers. TA augmented annexin-V staining, caspase activity, and c-PARP expression indicating the activation of apoptotic pathways. TA also decreased PC-3 cell invasion. TA significantly decreased the tumor weight and volume which was associated with low expression of Sp1 and survivin in tumor sections.

CONCLUSION

TA targets critical pathways associated with tumorigenesis and invasion. These pre-clinical data strongly demonstrated the anti-cancer activity of TA in prostate cancer.

Controversies in using urine samples for Prostate Cancer detection: PSA and PCA3 expression analysis

PURPOSE

Prostate cancer (PCa) is one of the most commonly diagnosed malignancies in the world. Although PSA utilization as a serum marker has improved prostate cancer detection it still presents some limitations, mainly regarding its specificity. The expression of this marker, along with the detection of PCA3 mRNA in urine samples, has been suggested as a new approach for PCa detection. The goal of this work was to evaluate the efficacy of the urinary detection of PCA3 mRNA and PSA mRNA without performing the somewhat embarrassing prostate massage. It was also intended to optimize and implement a methodological protocol for this kind of sampling.

MATERIALS AND METHODS

Urine samples from 57 patients with suspected prostate disease were collected, without undergoing prostate massage. Increased serum PSA levels were confirmed by medical records review. RNA was extracted by different methods and a preamplification step was included in order to improve gene detection by Real-Time PCR.

RESULTS

An increase in RNA concentration with the use of TriPure Isolation Reagent. Despite this optimization, only 15.8% of the cases showed expression of PSA mRNA and only 3.8% of prostate cancer patients presented detectable levels of PCA3 mRNA. The use of a preamplification step revealed no improvement in the results obtained.

CONCLUSION

This work confirms that prostate massage is important before urine collection for gene expression analysis. Since PSA and PCA3 are prostate specific, it is necessary to promote the passage of cells from prostate to urinary tract, in order to detect these genetic markers in urine samples.

Association between smoking status, and free, total and percent free prostate specific antigen

PURPOSE

There are scant data available on the relationship between smoking and total prostate specific antigen, free prostate specific antigen and percent-free prostate specific antigen. Given the high prevalence of smoking and the frequency of prostate specific antigen screening, it is important to determine any association between smoking and prostate specific antigen values using nationally representative data.

MATERIALS AND METHODS

Included in the final study population were 3,820 men 40 years old or older who participated in the 2001-2006 NHANES (National Health and Nutrition Examination Survey) and met the eligibility criteria for prostate specific antigen testing. The distributions of total, free and percent free prostate specific antigen were estimated by sociodemographic and clinical characteristics. Multivariate linear regression models were fit to determine the adjusted relationship between smoking and total and percent free prostate specific antigen while simultaneously controlling for these characteristics.

RESULTS

For all ages combined the median total and free prostate specific antigen levels were 0.90 (0.81-0.90) and 0.26 (0.25-0.28) ng/ml, respectively. Multivariate linear regression analysis showed that total prostate specific antigen was 7.9% and 12.2% lower among current and former smokers, respectively, than among never smokers. High body mass index and diabetes were also statistically significantly associated with a lower total prostate specific antigen. Approximately a third of the men had a percent free prostate specific antigen less than 25%. Current smokers had a significantly lower percent free prostate specific antigen than former smokers.

CONCLUSIONS

Our finding that smoking is inversely associated with total prostate specific antigen may have potential implications for the interpretation of prostate specific antigen levels in men who are current or former smokers. Given the high prevalence of smoking, obesity and diabetes, additional research on the combined effect of these health risk factors is warranted.

Risk factors for the onset of prostatic cancer: age, location, and behavioral correlates

At present, only three risk factors for prostate cancer have been firmly established; these are all nonmodifiable: age, race, and a positive family history of prostate cancer. However, numerous modifiable factors have also been implicated in the development of prostate cancer. In the current review, we summarize the epidemiologic data for age, location, and selected behavioral factors in relation to the onset of prostate cancer. Although the available data are not entirely consistent, possible preventative behavioral factors include increased physical activity, intakes of tomatoes, cruciferous vegetables, and soy. Factors that may enhance prostate cancer risk include frequent consumption of dairy products and, possibly, meat. By comparison, alcohol probably exerts no important influence on prostate cancer development. Similarly, dietary supplements are unlikely to protect against the onset of prostate cancer in healthy men. Several factors, such as smoking and obesity, show a weak association with prostate cancer incidence but a positive relation with prostate cancer mortality. Other factors, such as fish intake, also appear to be unassociated with incident prostate cancer but show an inverse relation with fatal prostate cancer. Such heterogeneity in the relationship between behavioral factors and nonadvanced, advanced, or fatal prostate cancers helps shed light on the carcinogenetic process because it discerns the impact of exposure on early and late stages of prostate cancer development. Inconsistent associations between behavioral factors and prostate cancer risk seen in previous studies may in part be due to uncontrolled detection bias because of current widespread use of prostate-specific antigen testing for prostate cancer, and the possibility that certain behavioral factors are systematically related to the likelihood of undergoing screening examinations. In addition, several genes may modify the study results, but data concerning specific gene-environment interactions are currently sparse. Despite large improvements in our understanding of prostate cancer risk factors in the past two decades, present knowledge does not allow definitive recommendations for specific preventative behavioral interventions.

Vitamin D metabolism and action in the prostate: implications for health and disease

Prostate cancer (PCa) is the second most common cancer in men worldwide. Epidemiological, molecular, and cellular studies have implicated vitamin D deficiency as a risk factor for the development and/or progression of PCa. Studies using cell culture systems and animal models suggest that vitamin D acts to reduce the growth of PCa through regulation of cellular proliferation and differentiation. However, although preclinical studies provide a strong indication for anti-cancer activity, proof of therapeutic benefits in men is still lacking. The anti-proliferative and pro-differentiating properties of vitamin D have been attributed to calcitriol [1,25(OH)(2)D(3)], the hormonally active form of vitamin D, acting through the vitamin D receptor (VDR). Metabolism of vitamin D in target tissues is mediated by two key enzymes: 1α-hydroxylase (CYP27B1), which catalyzes the synthesis of calcitriol from 25(OH)D and 24-hydroxylase (CYP24), which catalyzes the initial step in the conversion of calcitriol to less active metabolites. Many factors affect the balance of calcitriol synthesis and catabolism and several maneuvers, like combination therapy of calcitriol with other drugs, have been explored to treat PCa and reduce its risk. The current paper is an overview addressing some of the key factors that influence the biological actions of vitamin D and its metabolites in the treatment and/or prevention of PCa.

Associations of serum vitamin A and carotenoid levels with markers of prostate cancer detection among US men

Associations of serum vitamin A and carotenoid levels with markers of prostate cancer detection were evaluated among 3,927 US men, 40-85 years of age, who participated in the 2001-2006 National Health and Nutrition Examination Surveys. Five recommended definitions of prostate cancer detection were adopted using total and free prostate-specific antigen (tPSA and fPSA) laboratory measurements. Men were identified as high risk based on alternative cutoffs, namely tPSA > 10 ng/ml, tPSA > 4 ng/ml, tPSA > 2.5 ng/ml, %fPSA < 25%, and %fPSA < 15%. %fPSA was defined as (fPSA÷tPSA)× 100%. Serum levels of vitamin A (retinol and retinyl esters) and carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lutein + zeaxanthin, lycopene) were defined as quartiles and examined as risk/protective factors for PSA biomarkers. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using binary logistic models. After adjustment for known demographic, socioeconomic, and lifestyle confounders, high serum levels of retinyl esters (tPSA > 10 ng/ml: Q4 vs. Q1 → OR = 0.38, 95% CI: 0.14-1.00) and α-carotene (%fPSA < 15%: Q4 vs. Q1 → OR = 0.49, 95% CI: 0.32-0.76) were associated with a lower odds, whereas high serum level of lycopene (tPSA > 2.5 ng/ml: Q4 vs. Q1 → OR = 1.49, 95% CI: 1.01-2.14) was associated with a greater odds of prostate cancer detection. Apart from the three significant associations observed, no other exposure-outcome association was significant. Monitoring specific antioxidant levels may be helpful in the early detection of prostate cancer.

The effect of demographic and clinical factors on the relationship between BMI and PSA levels

INTRODUCTION

Studies have reported lower prostate specific antigen (PSA) levels in men with a higher body mass index (BMI). Additional factors such as diabetes mellitus, benign prostatic hyperplasia (BPH) and certain medications may also affect PSA levels and confound the PSA-BMI association. In this study we evaluated the potential confounding effect of these factors on the obesity-PSA relationship and evaluated the association between these factors and PSA level.

METHODS

The study cohort consisted of 770 population-based controls without a history of prostate cancer (PCa) who participated in a prior PCa study. Demographic, anthropometric, and medical history data were obtained, and PSA level was determined from blood drawn at the time of interview. Linear regression was performed to evaluate the PSA-BMI relationship, adjusting for potential confounders. Finally, a forward stepwise algorithm was used to determine which factors were independently associated with PSA values.

RESULTS

With increase in BMI (<25, 25-29, ≥30), the geometric mean PSA level declined (1.18, 1.13, and 0.94, respectively); obese men had a 17% (95% CI 0.70-0.99) lower age-adjusted PSA level compared to normal weight men. However, this relationship was non-significant (P = 0.17) in the multivariate model. Independent predictors of PSA level included age (β = 1.03, 95% CI 1.02-1.04), history of BPH (β = 1.48, 95% CI 1.27-1.72), current statin (β = 0.85, 95% CI 0.74-0.98), and NSAID use (β = 0.84, 95% CI 0.72-0.98).

CONCLUSION

The relationship between obesity and PSA is confounded by a number of factors, which likely explain the observed inverse association previously reported. These results should help in interpreting PSA values in men screened for PCa.

A large cohort study of long-term acetaminophen use and prostate cancer incidence

BACKGROUND

Use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAID), particularly long-term use, has been associated with modestly reduced risk of prostate cancer in previous epidemiologic studies. Acetaminophen, a commonly used pain reliever, is not traditionally considered an NSAID but can have anti-inflammatory effects. Few studies have examined the association between long-term acetaminophen use and prostate cancer incidence.

METHODS

We examined the association between acetaminophen use and prostate cancer incidence among 78,485 men in the Cancer Prevention Study II Nutrition Cohort. Information on acetaminophen use was obtained from a questionnaire completed at study enrollment in 1992 and updated by using follow-up questionnaires in 1997 and every two years thereafter. Relative risks (RR) were estimated by using proportional hazards regression models. All models were adjusted for age, race, education, body mass index, diabetes, NSAID use, and history of prostate-specific antigen testing.

RESULTS

During follow-up from 1992 through 2007, 8,092 incident prostate cancer cases were identified. Current regular use of acetaminophen (30 or more pills per month) for 5 or more years was associated with lower risk of overall prostate cancer (RR = 0.62, 95% CI: 0.44-0.87) and aggressive prostate cancer (RR = 0.49, 95% CI: 0.27-0.88). Current regular use of less than 5 years duration was not associated with prostate cancer risk.

CONCLUSION

These results suggest that long-term regular acetaminophen use may be associated with lower prostate cancer risk.

IMPACT

If the association between acetaminophen use and lower risk of prostate cancer is confirmed, it could provide clues about biological mechanisms that are important in prostate carcinogenesis.

Effect of statin use on biochemical outcome following radical prostatectomy

OBJECTIVE

•To determine the relationship between statin use and biochemical recurrence (BCR) following radical prostatectomy (RP).

PATIENTS AND METHODS

•A retrospective analysis was performed on 3198 RP patients between 1990 and 2008. •Exclusion criteria were neo-adjuvant or adjuvant therapy, follow-up <2 years, and insufficient pathological or prostate-specific antigen (PSA) data. •Statin use was determined from the patient's record. Clinical and pathological variables were compared between statin users and non-users. •Kaplan-Meier and multivariate Cox regression analyses were performed to determine the effect of statin use on BCR.

RESULTS

•A total of 1261 patients fit criteria for analysis. There were 281 (22%) statin users. Mean age was 60 years and median follow-up was 36 months (mean 43 months). •Statin users had a lower median preoperative PSA (6.4) compared with non-users (7.1) (P < 0.05). In all, 80% of statin users had a pathological Gleason sum ≥7 compared with 67% of non-users (P < 0.05). •On multivariate analysis, statin use was an independent predictor of BCR (hazard ratio 1.54, P < 0.05). Statin users had a lower 5-year BCR-free survival compared with non-users (75% vs 84%, P < 0.05).

CONCLUSIONS

•Statin users are at an increased risk for BCR following RP. This finding may be due to the reduction in preoperative PSA potentially delaying diagnosis and/or masking aggressive disease. •Further studies are necessary to elucidate the impact of statin medications following prostate cancer therapy.

Associations of aspirin, nonsteroidal anti-inflammatory drug and paracetamol use with PSA-detected prostate cancer: findings from a large, population-based, case-control study (the ProtecT study)

Evidence from laboratory studies suggests that chronic inflammation plays an important role in prostate cancer aetiology. This has resulted in speculation that nonsteroidal anti-inflammatory drugs may protect against prostate cancer development. We analysed data from a cross-sectional case-control study (n(cases) = 1,016; n(controls) = 5,043), nested within a UK-wide population-based study that used prostate specific antigen (PSA) testing for identification of asymptomatic prostate cancers, to investigate the relationship of aspirin, nonsteroidal anti-inflammatory drug (NSAID) and paracetamol use with prostate cancer. In conditional logistic regression models accounting for stratum matching on age (5-year age bands) and recruitment centre, use of non-aspirin NSAIDs [odds ratio (OR) = 1.32; 95% confidence interval (CI): 1.04-1.67] or all NSAIDs (OR = 1.25; 95% CI = 1.07-1.47) were positively associated with prostate cancer. There were weaker, not conventionally statistically significant, positive associations of aspirin (OR = 1.13; 95% CI = 0.94-1.36) and paracetamol (OR = 1.20; 95% CI = 0.90-1.60) with prostate cancer. Mutual adjustment for aspirin, non-aspirin NSAIDs or paracetamol made little difference to these results. There was no evidence of confounding by age, family history of prostate cancer, body mass index or self-reported diabetes. Aspirin, NSAID and paracetamol use were associated with reduced serum PSA concentrations amongst controls. Our findings do not support the hypothesis that NSAIDs reduce the risk of PSA-detected prostate cancer. Our conclusions are unlikely to be influenced by PSA detection bias because the inverse associations of aspirin, NSAID and paracetamol use with serum PSA would have attenuated (not generated) the observed positive associations.

Non-Steroidal Anti-Inflammatory Drugs, Variation in Inflammatory Genes, and Aggressive Prostate Cancer

Increasing evidence suggests that prostatic inflammation plays a key role in the development of prostate cancer. It remains controversial whether non-steroidal anti-inflammatory drugs (NSAIDs) reduce the risk of prostate cancer. Here, we investigate how a previously reported inverse association between NSAID use and the risk of aggressive prostate cancer is modulated by variants in several inflammatory genes. We found that NSAIDs may have differential effects on prostate cancer development, depending on one’s genetic makeup. Further study of these inflammatory pathways may clarify the mechanisms through which NSAIDs impact prostate cancer risk.

Impact of common medications on serum total prostate-specific antigen levels: analysis of the National Health and Nutrition Examination Survey

PURPOSE

Previous studies suggest that some common medications alter prostate-specific antigen (PSA) levels. It remains unclear whether these reported medication effects are due to clinicodemographic factors or concurrent use of other medications. We investigated the impact of individual and combinations of common medications on PSA in a large cross-sectional study of the United States population.

PATIENTS AND METHODS

The study included men > or = 40 years old without prostate cancer from the 2003 to 2004 and 2005 to 2006 cycles of the National Health and Nutrition Examination Survey (NHANES). Men with recent prostate manipulation, prostatitis, and those on hormone therapy were excluded. Weighted multivariate linear regression was performed on log-transformed total PSA to determine the effect of the 10 most commonly prescribed medication classes, adjusting for potential confounders including demographics, clinical characteristics, physical examination, laboratory studies, and duration of medication use.

RESULTS

In total, 1,864 men met inclusion criteria. Nonsteroidal anti-inflammatory drug (NSAID; P = .03), statin (P = .01), and thiazide diuretic (P = .025) intake was inversely related to PSA levels. Five years of NSAID, statin, and thiazide diuretic use was associated with PSA levels lower by 6%, 13%, and 26%, respectively. The combination of statins and thiazide diuretics showed the greatest reduction in PSA levels: 36% after 5 years. Concurrent calcium channel blocker use minimizes or negates the inverse relationship of statin use and PSA level.

CONCLUSION

We found that men using NSAIDs, statins, and thiazide diuretics have reduced PSA levels by clinically relevant amounts. The impact of regularly consuming these common medications on prostate cancer screening is unknown.

Prostate cancer prevention: concepts and clinical recommendations

Prevention is an important strategy for limiting prostate cancer morbidity and mortality. Two major types of prevention are primary (reduction of incident cases) and tertiary (inhibition of disease progression and recurrence). Pharmacological and dietary interventions have potential functions in both the primary and tertiary prevention of prostate cancer. Five-α reductase inhibitors (5-ARIs) reduce the incidence of prostate cancer in both general and higher-risk populations and are currently under study for tertiary prevention in active surveillance and biochemical recurrence patients. Selenium, vitamin E, and vitamin C do not prevent incident prostate cancer in the general population; however, other promising diet-based interventions are currently under study for tertiary prevention. We recommend consideration of 5-ARIs for prostate cancer prevention in (1) asymptomatic men with a PSA ≤ 3.0 ng ml(-1) who are undergoing or anticipate undergoing PSA screening for early detection of prostate cancer and (2) asymptomatic men with PSA ≥ 2.5 and ≤ 10 ng ml(-1) and an earlier prostate biopsy negative for cancer. Men should be informed of the potential risks of 5-ARI therapy. Currently, there is neither clinical evidence to support the use of 5-ARIs for tertiary prevention in active surveillance or biochemical recurrence populations, nor micronutrients for prostate cancer prevention of any type.

Hospitalization for osteoarthritis and prostate cancer specific mortality among Swedish men with prostate cancer

PURPOSE

To examine the potential role of nonsteroidal anti-inflammatory drugs (NSAIDs) use on prostate cancer (PCa) specific mortality.

METHODS

We studied the association between hospitalization for osteoarthritis prior to PCa diagnosis, as a surrogate for heavy use of NSAIDs, and PCa specific mortality in a large population of PCa patients in Sweden in 1980-2004.

RESULTS

Hospitalization for osteoarthritis before PCa diagnosis was associated to a lower PCa specific mortality (hazard ratio [HR], 0.92; 95% confidence interval [CI], 0.88-0.96), but not to the risk of death from other causes (HR, 1.03; 95% CI, 0.99-1.08). The association was stronger among younger patients and patients diagnosed in earlier calendar years.

CONCLUSIONS

Our data demonstrate a modestly decreased PCa specific mortality among PCa patients with hospitalization for osteoarthritis prior to PCa diagnosis, compared to those without such experience. This finding lends support to the hypothesis that NSAIDs use may influence PCa progression.

The impact of HMG-CoA reductase therapy on serum PSA

BACKGROUND

3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase inhibitors, otherwise known as statins, inhibit the enzyme that controls the conversion of HMG-CoA to mevalonate, a precursor for cholesterol. Statins may be important to prostate cancer biology by inhibiting cell growth, inflammation, and oxidative stress. The purpose of this study was to assess the influence of statin therapy on serum prostate-specific antigen (PSA) levels.

METHODS

The computerized medical records at the University of Rochester Medical Center were used to identify men who filled statin prescriptions between May 31st, 2008 and September 30th, 2008. Men with at least one PSA assay performed within 2 years before and at least one PSA assay performed within 1 year after starting a statin medication were included. The primary endpoint was the change in PSA concentration computed as the difference between PSA levels before and after starting a statin medication. Paired t-tests were used to analyze the mean differences in PSA values.

RESULTS

A total of 962 patients were identified. The mean difference in serum PSA level after statin administration was -0.29 ng/ml (-8.04%). Subgroup analyses for mean PSA concentration change before and after statin administration by age group revealed: 50-59 years old (-0.1609, 95% CI: -0.2444, -0.0775, P < 0.0002), 60-69 years old (-0.3393, 95% CI: -0.4641, -0.2145, P < 0.0001), and >70 years old (-0.351, 95% CI: -0.490, -0.212, P < 0.0001).

CONCLUSIONS

These observations suggest a statistically significant reduction in serum PSA level that is associated with the onset of statin therapy.

Identification of EP4 as a potential target for the treatment of castration-resistant prostate cancer using a novel xenograft model

More effective therapeutic approaches for castration-resistant prostate cancer (CRPC) are urgently needed, thus reinforcing the need to understand how prostate tumors progress to castration resistance. We have established a novel mouse xenograft model of prostate cancer, KUCaP-2, which expresses the wild-type androgen receptor (AR) and which produces the prostate-specific antigen (PSA). In this model, tumors regress soon after castration, but then reproducibly restore their ability to proliferate after 1 to 2 months without AR mutation, mimicking the clinical behavior of CRPC. In the present study, we used this model to identify novel therapeutic targets for CRPC. Evaluating tumor tissues at various stages by gene expression profiling, we discovered that the prostaglandin E receptor EP4 subtype (EP4) was significantly upregulated during progression to castration resistance. Immunohistochemical results of human prostate cancer tissues confirmed that EP4 expression was higher in CRPC compared with hormone-naïve prostate cancer. Ectopic overexpression of EP4 in LNCaP cells (LNCaP-EP4 cells) drove proliferation and PSA production in the absence of androgen supplementation in vitro and in vivo. Androgen-independent proliferation of LNCaP-EP4 cells was suppressed when AR expression was attenuated by RNA interference. Treatment of LNCaP-EP4 cells with a specific EP4 antagonist, ONO-AE3-208, decreased intracellular cyclic AMP levels, suppressed PSA production in vitro, and inhibited castration-resistant growth of LNCaP-EP4 or KUCaP-2 tumors in vivo. Our findings reveal that EP4 overexpression, via AR activation, supports an important mechanism for castration-resistant progression of prostate cancer. Furthermore, they prompt further evaluation of EP4 antagonists as a novel therapeutic modality to treat CRPC.

Cigarette smoking and prostate cancer in a prospective US cohort study

Smoking is an important risk factor for many cancers, yet the relationship between smoking and prostate cancer remains uncertain. We investigated whether smoking affected the risk of prostate cancers within a large prospective cohort study of dietary and environmental cancer risk factors among men ages 50 to 71 upon enrollment in 1995-1996 (n = 283,312). Cox proportional hazards regression models with hazard ratios (HR) and 95% confidence intervals (95% CI) were adjusted for age, race, education, height, body mass index, physical activity, family history of prostate cancer, diabetes, self-reported health status, prostate-specific antigen testing, digital rectal exam, total energy, alpha-tocopherol, calcium, alpha-linolenic acid, selenium, red meat, fish, and tomato intake. There were 14,810 nonadvanced and 1,830 advanced incident prostate cancers identified through 2003, and 394 men died of their disease through 2005. Current smokers had a decreased risk of nonadvanced prostate cancer (HR, 0.82; 95% CI, 0.77-0.88), but an increased risk of fatal prostate cancer (HR, 1.69; 95% CI, 1.25-2.27). Former smoking was also associated with decreased risk of nonadvanced prostate cancers (HR, 0.89; 95% CI, 0.86-0.92), but not fatal prostate cancers (HR, 1.03; 95% CI, 0.83-1.27). There was no apparent association between smoking and advanced prostate cancer. A number of biologically plausible mechanisms could explain these results, including the direct effects of carcinogens in tobacco smoke and the resulting changes in sex hormone or growth factor profiles. These findings suggest that current and former smokers may be at decreased risk of being diagnosed with prostate cancer and current smokers are at an increased risk of dying from prostate cancer.