Case-control study of lifetime total physical activity and prostate cancer risk

Voluntarily wheel running inhibits the growth of CRPC xenograft by inhibiting HMGB1 in mice

INTRODUCTION

Exercise has been proved to reduce the risk of recurrence and mortality of cancer. Emerging evidence indicated that exercise may regulate both systematical and local metabolism, immunity and other ways. Although the role of exercise in inhibiting castration-resistant prostate cancer is well established, the underlying mechanism remains unclear.

METHOD

Twenty C57BL/6 male mice were used to construct CRPC xenograft models and randomly divided into exercise group (n = 10) and control group (n = 10). After exercised with voluntarily wheel running for 21 days, the mice were sacrificed and the tumor tissues and serum were collected. TUNEL staining was used to detect the apoptosis of tumor cells. The expression of PI3K signal pathway and apoptosis related proteins were detected by Western blot. The expression of AR and HMGB1 were examined by Western blot and Immunohistochemical staining. IFN-γ, TNF-α, TGF-β, IL-4, IL-6, IL-10 in serum was examined using ELISA kits.

RESULTS

Voluntarily wheel running inhibited the growth of CRPC xenografts, inhibited the proliferation of tumor cells and promoted the apoptosis of tumor cells. HMGB1 levels in serum and tumor tissues were significantly reduced after exercise, which enhanced local immunity by inducing more leukocyte infiltration and inhibited systemic inflammatory response by regulating cytokines.

CONCLUSION

Voluntary wheel running can down-regulate the expression of HMGB1 in serum and transplanted tumor tissues, inhibit proliferation and promote apoptosis of tumor cells, enhance immune cell infiltration and systemic inflammatory response, and regulate local anti-tumor effects in tumor microenvironment.

Damaged Masculinity: How Honor Endorsement Can Influence Prostate Cancer Screening Decision-Making and Prostate Cancer Mortality Rates

Prior research has established factors that contribute to the likelihood that men seek out prostate cancer screenings. The current study addresses how endorsing the ideology found in cultures of honor may serve as a barrier to prostate cancer screenings. Two studies were conducted which analyzed the impact of stigma on men's decisions to seek out prostate cancer screenings (Study 1) as well as how prostate cancer deaths may be higher in the culture of honor regions due to men's reticence to seek out screenings (Study 2). Results suggest that older, honor-endorsing men are less likely to have ever sought out a prostate cancer screening due to screening stigma and that an honor-oriented region (southern and western United States) displays higher rates of prostate cancer death than a non-honor-oriented region (northern United States). These findings suggest that honor may be a cultural framework to consider when practitioners address patients' screening-related concerns.

Association of low meal frequency with decreased in vivo Alzheimer's pathology

Little is known about the association between meal frequency and Alzheimer's disease (AD) in humans. We tested the hypothesis that low meal frequency (LMF) is associated with reduced in vivo AD pathology in human brain, and additionally investigated the mediation of serum ghrelin, a hunger-related hormone, for the association. A total of 411 non-demented older adults were systematically interviewed to identify their dietary patterns including meal frequency and underwent multi-modal neuroimaging for cerebral beta-amyloid (Aβ) and tau deposition, glucose metabolism, and cerebrovascular injury. LMF (less than three meals a day) was significantly associated with lower Aβ deposition compared to high meal frequency (HMF). In addition, both LMF and reduced Aβ deposition were significantly related to elevated serum ghrelin. Our findings suggest that LMF may be related to the lower risk of AD through reduced brain amyloid deposition. Additionally, ghrelin appears mediate the association between LMF and lower amyloid deposition.

Chronic exercise training attenuates prostate cancer-induced molecular remodelling in the testis

PURPOSE

Prostate cancer is a major cause of cancer-related death in males worldwide and, in addition to impairing prostate function, also causes testicular adaptations. In this study, we aim to investigate the preventive effect of exercise training on PCa-induced testicular dysfunction.

METHODS

As a model, we used fifty Wistar Unilever male rats, randomly divided in four experimental groups. Prostate cancer was chemically and hormonally induced in two groups of animals (PCa groups). One control group and one PCa group was submitted to moderate intensity treadmill exercise training. Fifty weeks after the start of the training the animals were sacrificed and sperm, prostate, testis and serum were collected and analyzed. Sperm concentration and morphology, and testosterone serum levels were determined. In addition, histological analyses of the testes were performed, and testis proteomes and metabolomes were characterized.

RESULTS

We found that prostate cancer negatively affected testicular function, manifested as an arrest of spermatogenesis. Oxidative stress-induced DNA damage, arising from reduced testis blood flow, may also contribute to apoptosis of germ cells and consequential spermatogenic impairment. Decreased utilization of the glycolytic pathway, increased metabolism of ketone bodies and the accumulation of branched chain amino acids were also evident in the PCa animals. Conversely, we found that the treadmill training regimen activated DNA repair mechanisms and counteracted several metabolic alterations caused by PCa without impact on oxidative stress.

CONCLUSIONS

These findings confirm a negative impact of prostate cancer on testis function and suggest a beneficial role for exercise training in the prevention of prostate cancer-induced testis dysfunction.

Effect of time of day of recreational and household physical activity on prostate and breast cancer risk (MCC-Spain study)

Experimental evidence indicates that exercise performed at different times of the day may affect circadian rhythms and circadian disruption has been linked to breast and prostate cancer. We examined in a population-based case-control study (MCC-Spain) if the time-of-day when physical activity is done affects prostate and breast cancer risk. Lifetime recreational and household physical activity was assessed by in-person interviews. Information on time-of-day of activity (assessed approximately 3 years after the assessment of lifetime physical activity and confounders) was available for 781 breast cancer cases, 865 population female controls, 504 prostate cases and 645 population male controls from 10 Spanish regions, 2008-2013. We estimated odds ratios (ORs) and 95% confidence intervals (95% CI) for different activity timings compared to inactive subjects using unconditional logistic regression adjusting for confounders. Early morning (8-10 am) activity was associated with a protective effect compared to no physical activity for both breast (OR = 0.74, 95% CI = 0.48-1.15) and prostate cancer (OR = 0.73, 95% CI = 0.44-1.20); meta-OR for the two cancers combined 0.74 (95%CI = 0.53-1.02). There was no effect observed for breast or prostate cancer for late morning to afternoon activity while a protective effect was also observed for evening activity only for prostate cancer (OR = 0.75, 95% CI = 0.45-1.24). Protective effects of early morning activity were more pronounced for intermediate/evening chronotypes for both cancers. This is the first population-based investigation identifying a differential effect of timing of physical activity on cancer risk with more pronounced effects for morning hour activity. Our results, if confirmed, may improve current physical activity recommendations for cancer prevention.

Transportation Physical Activity Earlier in Life and Areas of the Brain related to Dementia Later in Life

INTRODUCTION

Efforts to preserve brain function may be most effective when administered before there are changes in the brain, which may occur decades before the onset of Alzheimer's disease symptoms. White matter hyperintensities (WMH), a cardiovascular disease biomarker, are areas of hyperintense signals scattered in the white matter of the brain evident on magnetic resonance images. WMH increase with age and are associated with a higher risk of dementia. The purpose of this study was to determine if there was an association between different domains and intensities of physical activity earlier in life and lower risk of dementia later in life as indicated by less WMH.

METHODS

In this cross-sectional study, face-to-face interviews were conducted with the Lifetime Total Physical Activity Questionnaire. The metabolic equivalent of task (MET) hours/week/year of moderate (3.0-5.9 METs) and vigorous-intensity (≥6 METs) occupation, transportation, household and leisure-time physical activity was obtained across school-age (6-11), adolescence (12-18), young (19-39) and middle adulthood (40-64). WMH were calculated as the percent of intracranial volume in cognitively unimpaired middle (age 40-64) and older adults (age 65+). Simultaneous multiple linear regression determined associations between moderate and vigorous-intensity occupation, transportation, household and leisure-time physical activity across school-age, adolescence, young and middle adulthood with WMH.

RESULTS

Greater moderate-intensity transportation physical activity during young (b= -.09, p=.008) and middle adulthood (b= -.14, p=.013) was associated with lower WMH in middle and older adulthood, explaining 28% (p=.003) to 29% (p=.002) of the variance in WMH (n=54).

CONCLUSIONS

Changes to the physical environment that encourage walking, running or biking, such as sidewalks and bike paths, may be strategies to mitigate the age-related increases in WMH, areas of the brain associated with higher risk of dementia.

Physical Activity and Breast Cancer: A Case-Control Study in Southern Brazil

Physical inactivity is one of the greatest public health challenges in the 21st century. More than five million deaths a year are caused by lack of physical activity (PA) around the world. Despite its relevance to public health, about one-third of the world's adults do not meet current PA recommendations for health benefits. Thus, the aim of the present study was to investigate the association between lifetime PA and risk of breast cancer. A case-control study was conducted between November 2016 and June 2017. The cases were recruited from all cancer centers in the city of Pelotas in southern Brazil. Each case was age-matched (±5 years) with a neighborhood control enrolled based on nearby addresses of the cases. Overall, 230 cases and 231 controls were included. Lifetime leisure-time PA may decrease the odds of breast cancer (adjusted OR = 0.44; 95%CI 0.23-0.86) in the comparison between the most active with the least active quartile. PA was associated with a reduction in the odds of breast cancer. Future studies should aim at understanding the physiological pathways that could explain how an active lifestyle influences this disease, helping in the establishment of volume and intensities necessary to obtain the benefits.

Midlife Lifestyle Activities Moderate APOE ε4 Effect on in vivo Alzheimer's Disease Pathologies

This study aimed to investigate whether the midlife cognitive activity and physical activity moderate the relationship between apolipoprotein Eε4 (APOE4) and in vivo Alzheimer's disease (AD) pathologies. In total, 287 non-demented older adults (mean age 72 years) from the Korean Brain Aging Study for the Early diagnosis and prediction of Alzheimer's disease cohort were included. Participants underwent a comprehensive clinical assessment including the evaluation for midlife CA and physical activity, [¹¹C]-Pittsburgh-Compound-B-positron emission tomography (PET), [¹⁸F]-fluorodeoxyglucose PET, structural magnetic resonance imaging (MRI), and APOE genotyping. We used linear regression and regression-based mediated-moderation models for statistical analyses. Neither midlife cognitive activity nor physical activity moderated the effect of APOE4 on β-amyloid (Aβ) retention itself. Midlife cognitive activity significantly moderated the effect of APOE4 on hippocampal volume [B (SE) = - 627.580 (252.327), t = -2.488, p = 0.014]: APOE4 carriers had smaller hippocampal volume than non-carriers at relatively high cognitive activity state (p = 0.004), but not at relatively low cognitive activity condition (p = 0.937). Midlife physical activity significantly moderated the effect of Aβ retention, which was closely related to APOE4, on AD-signature region cerebral glucose metabolism [AD-CM; B (SE) = 0.004 (0.002), t = 2.030, p = 0.043]: higher Aβ accumulation was associated with lower AD-CM in relatively low physical activity condition (p < 0.001), whereas no such association was observed in relatively high physical activity state (p = 0.791). The findings suggest that high midlife cognitive activity may accelerate hippocampal atrophy induced by APOE4, whereas high midlife physical activity may delay AD-related cerebral hypometabolism by weakening the influence of APOE4-associated Aβ retention.

Lifestyle in urology: Cancer

The opportunity to prevent, to improve their prognosis, or even to cure uro-oncological diseases by modifying the lifestyle habits is a very modern topical subject and represents a great and fascinating challenge for the future. A PubMed and Web of Science databases search has been performed to review the published knowledge on most important lifestyle habits, such as smoking, physical activity, nutrition, sexual activity, and personal hygiene, highlighting modifiable factors influencing development and progression of urological cancers. Cigarette smoking has been historically established as risk factors for urothelial cancer, and an association with risk of renal cell carcinoma and worse prognosis of prostate cancer has been sufficiently demonstrated. Poor genital hygiene is a recognized risk factor for penile cancer. Furthermore, a convincing evidence has been found on the association between physical activity and both risk and prognosis of bladder and prostate cancer. Obesity is strongly associated with increased risk of developing lethal prostate cancer. An unequivocal evidence of a direct relationship between most of the other lifestyle habits and development of the uro-oncological diseases has not been found.

Nexrutine and exercise similarly prevent high grade prostate tumors in transgenic mouse model

The purpose of this investigation was to compare the antitumorigenic effects of the natural product Nexrutine to voluntary wheel running (VWR) in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Forty-five, 10-week old TRAMP mice were randomized to either receive free access to the running wheel, Nexrutine pelleted into chow at 600 mg/kg or no treatment control. Mice were serially sacrificed at weeks 4, 8,12 and 20 weeks. Palpable tumors, body weight, food consumption and running wheel activity were monitored weekly. At necropsy, tumors and serum were harvested and stored for analysis. Serum was used to quantify circulating cytokines in 4 and 20 week time points. Nexrutine supplementation led to a 66% protection against high grade tumors. Exercise resulted in a 60% protection against high grade tumors. Both interventions reduced concentrations of IL-1α. Exercise also significantly lowered concentrations of eotaxin, IL-5, IL-12(p40) and VEGF. While there were no significant differences at baseline, exercise mice had significantly lower IL-5 and VEGF compared to control at the 20 week time point. Nexrutine also significantly reduced circulating IL-9 concentrations. No significant differences were observed when compared to the control group. Immunohistochemistry of tumor sections showed significantly lower expression of pAkt in Nexrutine fed mice with no visible differences for NFκB. In conclusion, both Nexrutine and exercise suppressed tumor growth. Though similar outcomes were seen in this comparative effectiveness study, the mechanisms by which exercise and Nexrutine exert this benefit may focus on different pathways.

Lifetime Physical Activity and White Matter Hyperintensities in Cognitively Intact Adults

BACKGROUND

White matter hyperintensities (WMHs) observed on magnetic resonance images are associated with depression and increase the risk of stroke, dementia, and death. The association between physical activity and WMHs has been inconsistently reported in the literature, perhaps because studies did not account for a lifetime of physical activity or depression.

OBJECTIVES

The aim of this study was to determine the extent to which a lifetime of leisure-time physical activity is associated with less WMHs while accounting for depression.

METHODS

Face-to-face interviews were conducted with the Lifetime Total Physical Activity Questionnaire, where the metabolic equivalent of task hours per week per year was calculated. Cognitively intact participants also underwent magnetic resonance imaging, where WMHs as a percentage of intracranial volume was obtained. Hierarchical multiple linear regression was performed to compare WMHs in a more active group with a group with no psychiatric history (n = 20, mean age = 62.2 years), with a less active group with no psychiatric history (n = 13, mean age = 64.0 years), and a less active group with history of late-onset depression (n = 14, mean age = 62.8 years).

RESULTS

There was not a statistically significant difference in WMHlg10 between the more and less active groups without a psychiatric history (b = .09, p > .05) or between the more active group without a psychiatric history and the less active group with a history of depression (b = .01, p > .05). The model was predictive of WMHlg10, explaining an adjusted 15% of the variance in WMHs (p = .041).

DISCUSSION

A lifetime of leisure-time physical activity was not associated with WMHs when accounting for depression.

Physical activity in relation to risk of prostate cancer: a systematic review and meta-analysis

Background

Prostate cancer (PCa) is one of the most common cancers among men, yet little is known about its modifiable risk and protective factors. This study aims to quantitatively summarize observational studies relating physical activity (PA) to PCa incidence and mortality.

Materials and methods

Published articles pertaining to PA and PCa incidence and mortality were retrieved in July 2017 using the Medline and EMBASE databases. The literature review yielded 48 cohort studies and 24 case-control studies with a total of 151 748 PCa cases. The mean age of the study participants at baseline was 61 years.

Results

In random-effects models, comparing the highest versus the lowest level of overall PA showed a summary relative risk (RR) estimate for total PCa incidence close to the null [RR = 0.99, 95% confidence interval (CI) = 0.94-1.04]. The corresponding RRs for advanced and non-advanced PCa were 0.92 (95% CI = 0.80-1.06) and 0.95 (95% CI = 0.85-1.07), respectively. We noted a statistically significant inverse association between long-term occupational activity and total PCa (RR = 0.83, 95% CI = 0.71-0.98, n studies = 13), although that finding became statistically non-significant when individual studies were removed from the analysis. When evaluated by cancer subtype, an inverse association with long-term occupational activity was noted for non-advanced/non-aggressive PCa (RR = 0.51, 95% CI = 0.37-0.71, n studies = 2) and regular recreational activity was inversely related to advanced/aggressive PCa (RR = 0.75, 95% CI = 0.60-0.95, n studies = 2), although these observations are based on a low number of studies. Moreover, PA after diagnosis was related to reduced risk of PCa mortality among survivors of PCa (summary RR based on four studies = 0.69, 95% CI = 0.55-0.85).

Conclusions

Whether PA protects against PCa remains elusive. Further investigation taking into account the complex clinical and pathologic nature of PCa is needed to clarify the PA and PCa incidence relation. Moreover, future studies are needed to confirm whether PA after diagnosis reduces risk of PCa mortality.

Occupational Risk Factors for Prostate Cancer: A Meta-analysis

Prostate cancer is the second most common cancer in men worldwide. There are many occupational factors that have been suggested to cause prostate cancer. Our aim was to evaluate the evidence for causality by a literature review of occupational factors. We searched literature in Medline and SCOPUS from 1966 to June 30, 2015 to identify occupational risk factors for prostate cancer. The following risk factors were selected: farmers/agricultural workers, pesticides - whole group, and separately organophosphate and organochlorine pesticides, carbamates and triazines, cadmium, chromium, cutting fluids, acrylonitrile, rubber manufacturing, whole body vibration, shift work, flight personnel, ionizing radiation, and occupational physical activity. For each factor a literature search was performed and presented as meta-analysis of relative risk and heterogeneity (Q and I2 index). A total of 168 original studies met the inclusion criteria with 90,688 prostate cancer cases. Significantly increased risks were observed for the following occupational exposures: pesticides (metaRR = 1.15, 95% confidence interval [CI] = 1.01-1.32; I2 = 84%), and specifically group of organochlorine pesticides (meta relative risk [metaRR] = 1.08, 95% CI = 1.03-1.14; I2 = 0%), chromium (metaRR = 1.19, 95% CI = 1.07-1.34; I2 = 31%), shift work (metaRR = 1.25, 95% CI = 1.05-1.49; I2 = 78%) and pilots (metaRR = 1.41, 95% CI = 1.02-1.94; I2 = 63%) and occupational physical activity in cohort studies (metaRR = 0.87, 95% CI = 0.81-0.94; I2 = 0%). The literature review supports a causal association for a few of the previously suggested factors.

Physical Activity and Prostate Cancer: An Updated Review

Prostate cancer affects a major proportion of older men, and effective preventive measures are few. Earlier suggestions of 10-30% risk reduction from vigorous physical activity thus merit further analysis. This narrative review updates information on associations between physical activity and prostate cancer, seeking activity patterns associated with maximal risk reduction. Systematic searches of Ovid/MEDLINE and PubMed databases from 1996 to June 2016 have linked the terms prostate neoplasms/prostate cancer with occupation, occupational title, sedentary job or heavy work, exercise, physical activity, sports, athletes, physical education/training or aerobic fitness. Combining these searches with findings from earlier reviews, 85 analyses were captured, although three were repeat analyses of the same data set. Seven analyses reported increased risk, and a further 31 showed no clear relationship. However, 24 analyses found a trend to diminished risk, and 21 a significant decrease (10-30% or more) in at least some subject subsets. Benefit was seen more consistently in occupational than in leisure studies, usually with adolescence or the early 20 s as the optimal age for preventive activity. In general, benefit showed a dose-response relationship, with vigorous activity required for maximal effect. Furthermore, several recent observational studies have indicated that physical activity is beneficial in preventing disease recurrence and improving survival following the diagnosis and treatment of prostate cancer. Despite continued research, conclusive proof of an association between regular physical activity and a low risk of prostate cancer remains elusive. However, reports that exercise exacerbates risk are few, and despite issues around controls, covariates, and co-morbidities, an impressive number of studies have now found significant benefit, suggesting that regular physical activity is important in terms of disease development, progression, and therapy. Given also the many other health benefits of an active lifestyle, it can be recommended as a potentially useful measure in the prevention of prostate cancer.

Latest Evidence on the Impact of Smoking, Sports, and Sexual Activity as Modifiable Lifestyle Risk Factors for Prostate Cancer Incidence, Recurrence, and Progression: A Systematic Review of the Literature by the European Association of Urology Section of Oncological Urology (ESOU)

CONTEXT

Smoking, sexual activity, and physical activity (PA) are discussed as modifiable lifestyle factors associated with prostate cancer (PCa) development and progression.

OBJECTIVE

To evaluate the available evidence concerning the association of smoking, sexual activity, and sports and exercise on PCa risk, treatment outcome, progression, and cancer-specific mortality.

EVIDENCE ACQUISITION

A systematic review of studies published between 2007 and 2017 using MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement criteria was conducted.

EVIDENCE SYNTHESIS

While data concerning the impact of smoking on PCa development remain conflicting, there is robust evidence that smoking is associated with aggressive tumor features and worse cancer-related outcome, which seems to be maintained for 10 yr after smoking cessation. Less convincing and limited evidence exists for the association of sexual activity with PCa risk. The findings related to PA and PCa support the inference that exercise might be a useful factor in the prevention of PCa and tumor progression, while it is not finally proved under which specific conditions PA might be protective against disease development.

CONCLUSIONS

Smoking is associated with aggressive tumor features and worse cancer-related prognosis; as this negative impact seems to be maintained for 10yr after smoking cessation, urologists should advise men to quit smoking latest at PCa diagnosis to improve their prognosis. As several studies indicate a positive impact of exercise on tumor development, progression, and treatment outcome, it is certainly reasonable to advocate an active lifestyle. Least convincing evidence is available for the interaction of sexual activity and PCa, and well-conducted and longitudinal studies are clearly necessary to evaluate whether the suggested associations between PCa risk and sexual behavior are real or spurious.

PATIENT SUMMARY

In this systematic review, we looked at the impact of smoking, sexual activity, and sports and exercise on prostate cancer risk and outcome after treatment. While the evidence for sexual activity is not overall clear, we found that smoking might lead to more aggressive cancers and result in worse treatment outcome. Physical activity might prevent prostate cancer and improve cancer-related outcomes as well. Hence, it is certainly reasonable to advocate an active lifestyle and advise men to quit smoking.

Post-diagnosis alcohol intake and prostate cancer survival: A population-based cohort study

Alcohol consumption has been declared a Group 1 carcinogen by the International Agency for Research on Cancer (IARC) and is a potential risk factor for several types of cancer mortality. However, evidence for an association with prostate cancer survival remains inconsistent. We examined how alcohol consumption post-diagnosis was associated with survival after prostate cancer diagnosis. Men diagnosed with prostate cancer (n = 829) in Alberta, Canada between the years 1997 and 2000 were recruited into a population-based case-control study and then followed for up to 19 years for survival outcomes. Pre- and post-diagnosis alcohol consumption, clinical characteristics and lifestyle factors were collected through in-person interviews shortly after diagnosis and again 2-3 years post-diagnosis. Cox proportional hazards were used to examine how post-diagnosis alcohol consumption was associated with all-cause and prostate cancer-specific mortality (competing risk analysis too), in addition to first recurrence/progression or new primary cancer. Most participants reported drinking alcohol (≥once a month for 6 months) post-diagnosis (n = 589, 71.0%). Exceeding Canadian Cancer Society (CCS) alcohol consumption recommendations (≥2 drinks/day) post-diagnosis was associated with prostate cancer-specific mortality relative to non-drinkers (aHR: 1.82, 95% CI: 1.07-3.10) with borderline evidence of a linear trend. Interestingly, those in the highest quartile of drinks/week pre- and post-diagnosis also had a twofold increase for prostate-specific mortality (aHR: 2.67, 95% CI: 1.28-5.56) while controlling for competing risks. Our results support post-diagnosis alcohol consumption was associated with increased mortality after prostate cancer diagnosis, specifically for prostate cancer-related death. Future studies focused on confirming this burden of disease are warranted.

Anthropometric measurements and survival after a prostate cancer diagnosis

BACKGROUND

Evidence regarding the role of anthropometrics in prostate cancer survival is inconsistent. We examined the associations between anthropometric measures and survival outcomes.

METHODS

Men diagnosed with prostate cancer (n=987) were recruited into a population-based case-control study between 1997 and 2000 then a prospective cohort study between 2000 and 2002 where anthropometric measurements (weight, height, body mass index, waist circumference, waist-hip ratio) were taken and participants were followed up to 19 years for survival outcomes. Cox proportional hazards were used to examine these associations.

RESULTS

Survival analyses suggested no clear pattern of associations between post-diagnosis anthropometric measurements and all-cause mortality, prostate-specific mortality, first recurrence/progression or new primary cancer.

CONCLUSIONS

We did not find a significant trend relating anthropometrics to survival outcomes after prostate cancer diagnosis. Continued assessment of objective measurements of body composition over the life-course is warranted to determine true associations between anthropometrics and survival after prostate cancer.

Relationships between physical activity across lifetime and health outcomes in older adults: Results from the NuAge cohort

This study aims to (1) describe participation in four physical activity (PA) domains across life and (2) examine the influence of PA during adolescence, early, middle, and later adulthood on health variables at older age. This observational study was conducted in 1378 generally healthy older adults (age 67-84 at baseline in 2003-2005; 52% women) in Quebec, Canada. Using a modified version of the interviewer-administered Lifetime Total Physical Activity Questionnaire (LTPAQ) and life events calendar to facilitate the recall, participants reported the frequency, duration, and intensity of occupational (OPA), commuting (CPA), household (HPA), and leisure time (LTPA) they participated in at age 15, 25, 45, and 65, and at the first follow-up (age 68-85 in 2005-2006). Fat mass, lean body mass, body mass index, waist-to-hip ratio, fasting glucose, systolic and diastolic blood pressures, self-reported chronic diseases, and socio-demographic data were assessed at baseline. Changes in PA over time differed by sex in each domain. However, there was a general decline in all PA domains in both sexes after age 65. In multiple regression analyses, LTPA at first-follow-up was associated with more favourable waist-to-hip ratio in both sexes, fat mass in women and fat mass percentage in men, whereas CPA, OPA, and HPA across life were not consistently associated with health variables. Older adults' LTPA at first follow-up was related to health variables, but PA recalled during adolescence, early adulthood, and mid-life was not. Results support the idea that current PA is positively related to better health outcomes.

Exercise and Prostate Cancer: Evidence and Proposed Mechanisms for Disease Modification

Exercise has many potential benefits in relation to cancer. Apart from primary prevention, these include improvement of nonspecific cancer-related symptoms, amelioration of symptoms and cardiovascular risk factors related to cancer treatment, and improvements in various quality-of-life-related factors. Increasing evidence also points toward improved cancer-free and overall survival in cancer patients who undertake regular exercise, findings which should encourage further research in this area. Obesity is known to be associated with a proinflammatory, prothrombotic humoral milieu, which may promote aggressiveness in prostate cancer through interactions with NK-cell-mediated killing of circulating tumor cells, through platelet-circulating tumor cell interactions, and through alterations in adipokine and myokine profile among others. Physical activity reduces levels of systemic inflammatory mediators and so exercise may represent an accessible and cost-effective means of ameliorating the proinflammatory effects of obesity in cancer patients. This review outlines the evidence for the benefits of exercise in these patients, focusing on prostate cancer, and delineates current theories of the underlying biological mechanisms. Cancer Epidemiol Biomarkers Prev; 25(9); 1281-8. ©2016 AACR.

Hair dye use, regular exercise, and the risk and prognosis of prostate cancer: multicenter case-control and case-only studies

Background

This study investigated the effects that hair dye use and regular exercise exert on the risk and prognosis of prostate cancer.

Methods

We studied 296 cases of histologically confirmed prostate cancer and 296 age- (in 2-y bands), ethnicity-, and hospital-matched controls in Taiwan between August 2000 and December 2008. To determine the rate of prostate cancer survival, another 608 incident prostate cancer cases occurring between August 2000 and December 2007 were investigated. Information on hair dye use and regular exercise was obtained using a standardized questionnaire.

Results

The use of hair dyes was associated with a significant 2.15-fold odds of developing prostate cancer (adjusted odds ratio = 2.15, 95 % confidence interval [CI] = 1.32–3.57), but was not associated with prostate cancer survival, compared with no use. The significant risks were more prominent in users aged < 60 years who had used hair dyes for > 10 years, > 6 times per year, and started using hair dyes before 1980. By contrast, regular exercise significantly reduced the number of prostate-cancer-specific death (adjusted hazard ratio = 0.37, 95 % CI = 0.16–0.83); the protective effect of exercise was more prominent among cancer patients who exercised daily (≥7 times/week). However, exercise could not prevent the development of prostate cancer.

Conclusions

Hair dye use increased the risk of prostate cancer, whereas regular exercise reduced the number of prostate-cancer-specific deaths.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2280-7) contains supplementary material, which is available to authorized users.

Physical Activity and Survival After Prostate Cancer

BACKGROUND

Despite the high global prevalence of prostate cancer (PCa), few epidemiologic studies have assessed physical activity in relation to PCa survival.

OBJECTIVE

To evaluate different types, intensities, and timing of physical activity relative to PCa survival.

DESIGN, SETTING, AND PARTICIPANTS

A prospective study was conducted in Alberta, Canada, in a cohort of 830 stage II-IV incident PCa cases diagnosed between 1997 and 2000 with follow-up to 2014 (up to 17 yr). Prediagnosis lifetime activity was self-reported at diagnosis. Postdiagnosis activity was self-reported up to three times during follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cox proportional hazards models related physical activity to all-cause and PCa-specific deaths and to first recurrence/progression of PCa.

RESULTS AND LIMITATIONS

A total of 458 deaths, 170 PCa-specific deaths, and, after first follow-up, 239 first recurrences/progressions occurred. Postdiagnosis total activity (>119 vs ≤42 metabolic equivalent [MET]-hours/week per year) was associated with a significantly lower all-cause mortality risk (hazard ratio [HR]: 0.58; 95% confidence interval [CI], 0.42-0.79; p value for trend <0.01). Postdiagnosis recreational activity (>26 vs ≤4 MET-hours/week per year) was associated with a significantly lower PCa-specific mortality risk (HR: 0.56; 95% CI, 0.35-0.90; p value for trend = 0.01). Sustained recreational activity before and after diagnosis (>18-20 vs <7-8 MET-hours/week per year) was associated with a lower risk of all-cause mortality (HR: 0.66; 95% CI, 0.49-0.88). Limitations included generalisability to healthier cases and an observational study design.

CONCLUSIONS

These findings support emerging recommendations to increase physical activity after the diagnosis of PCa and would inform a future exercise intervention trial examining PCa outcomes.

PATIENT SUMMARY

In a 17-yr prostate cancer (PCa) survival study, men who survived at least 2 yr who were more physically active postdiagnosis or performed more recreational physical activity before and after diagnosis survived longer. Recreational physical activity after diagnosis was associated with a lower risk of PCa death.

Household physical activity and cancer risk: a systematic review and dose-response meta-analysis of epidemiological studies

Controversial results of the association between household physical activity and cancer risk were reported among previous epidemiological studies. We conducted a meta-analysis to investigate the relationship of household physical activity and cancer risk quantitatively, especially in dose-response manner. PubMed, Embase, Web of science and the Cochrane Library were searched for cohort or case-control studies that examined the association between household physical activity and cancer risks. Random–effect models were conducted to estimate the summary relative risks (RRs), nonlinear or linear dose–response meta-analyses were performed to estimate the trend from the correlated log RR estimates across levels of household physical activity quantitatively. Totally, 30 studies including 41 comparisons met the inclusion criteria. Total cancer risks were reduced 16% among the people with highest household physical activity compared to those with lowest household physical activity (RR = 0.84, 95% CI = 0.76–0.93). The dose-response analyses indicated an inverse linear association between household physical activity and cancer risk. The relative risk was 0.98 (95% CI = 0.97–1.00) for per additional 10 MET-hours/week and it was 0.99 (95% CI = 0.98–0.99) for per 1 hour/week increase. These findings provide quantitative data supporting household physical activity is associated with decreased cancer risk in dose-response effect.

Factors associated with prostate cancer screening behavior among men over 50 in Fasa, Iran, based on the PRECEDE model

BACKGROUND

Prostate cancer is one of the most common and lethal cancers in the world. The incidence of prostate cancer has been increasing in recent years. The purpose of this study was to investigate factors associated with prostate cancer screening behaviors among men over 50 in Fasa, Iran, based on the PRECEDE model.

METHODS

In this cross-sectional study, 400 men over 50 were studied in Fasa, Iran. Data were collected via a questionnaire on demographic characteristics, such as age, number of children, occupation, education, marital status, smoking, and prostate cancer screening behaviors. Data were analyzed using SPSS software, version 16. Independent samples t-test and the Pearson Product Moment correlation coefficient were used for the statistical analyses.

RESULTS

Men in the study had little knowledge (34.11±8.22) and attitude (28.23±7.23) about prostate cancer and screening behavior. Their mean scores about prostate cancer, screening behavior, quality of life, and general health were moderate. The subjects had low self-efficacy and perceived social support. Their mean scores of enabling factors and screening behaviors were at a low level. Pearson correlation scores showed a significant correlation between cancer prostate screening behavior and demographic variables, such as age (p=0.04, r=0.136), occupation (p=0.01, r=0.121), educational level (p=0.02, r=0.211), and marital status of the subjects (p=0.01, r=0.112), but there were not significant correlations with the number of children (p=0.12, r=0.092) and smoking (p=0.09, r=0.002). The T-test results showed significant relationships between age, occupation, and education of the subjects, and the PRECEDE model structures were significant for predisposing factors, enabling factors, and reinforcing factors (p<0.05).

CONCLUSION

The prostate cancer screening behaviors in men over 50 in Fasa, Iran, were at a low level. Due to predisposing factors, such as the knowledge, attitudes, and beliefs of individuals, reinforcing factors can have an important role in the behaviors related to prostate screening, such as their families and health staffs as well as enabling factors, such as health financing, access to medicines and learning self-care. Educational interventions to improve these behaviors and the quality of life of these people seem essential.

Physical activity and its mechanistic effects on prostate cancer

Beneficial effects of physical activity have been illustrated in numerous aspects of health. With the increasing incidence of prostate cancer and changes in physical activity of men, understanding the link between the two has important implications for changing this cancer burden. Both positive and negative associations between physical activity and prostate cancer have been previously demonstrated in observational epidemiological studies. Elucidating the biological mechanisms would lead to a better understanding of how physical activity influences the progression of prostate cancer. This review was undertaken to: (1) identify evidence in literature that demonstrates the effects of physical activity on skeletal muscle secretomes, (2) indicate the plausible signaling pathways these proteins might activate, and (3) identify evidence in literature that demonstrates the roles of the signaling pathways in prostate cancer progression and regression. We also discuss proposed biological mechanisms and signaling pathways by which physical activity may prevent the development and progression of prostate cancer. We discuss proteins involved in the normal and aberrant growth and development of the prostate gland that may be affected by physical activity. We further identify future directions for research, including a better understanding of the biological mechanisms, the need to standardize physical activity and identify mechanistic end points of physical activity that can then be correlated with outcomes.

Physical activity and its relation to cancer risk: updating the evidence

Scientific evidence for the primary prevention of cancer caused by physical activity of regular moderate-intensity or greater is rapidly accumulating in this field. About 300 epidemiologic studies on the association between physical activity and cancer risk have been conducted worldwide. The objectives of this paper were three-fold: (i) to describe briefly the components of physical activity and its quantification; (ii) to summarize the most important conclusions available from comprehensive reports, and reviews of the epidemiologic individual and intervention studies on a role physical activity in cancer prevention; (iii) to present proposed biological mechanisms accounting for effects of activity on cancer risk. The evidence of causal linked physical activity and cancer risk is found to be strong for colon cancer - convincing; weaker for postmenopausal breast and endometrium cancers - probable; and limited suggestive for premenopausal breast, lung, prostate, ovary, gastric and pancreatic cancers. The average risk reductions were reported to be 20-30%. The protective effects of physical activity on cancer risk are hypothesized to be through multiple interrelated pathways: decrease in adiposity, decrease in sexual and metabolic hormones, changes in biomarkers and insulin resistance, improvement of immune function, and reduction of inflammation. As there are several gaps in the literature for associations between activity and cancer risk, additional studies are needed. Future research should include studies dealing with limitations in precise estimates of physical activity and of a lack of consensus on what defines sedentary behavior of individuals and those linked with the proposed biomarkers to cancer risk and controlled exercise intervention trials.

Variation in HNF1B and Obesity May Influence Prostate Cancer Risk in African American Men: A Pilot Study

Background. Prostate cancer (PCa) racial disparity is multifactorial, involving biological, sociocultural, and lifestyle determinants. We investigated the association between selected potentially functional polymorphisms (SNPs) and prostate cancer (PCa) risk in Black (AAM) and White (EAM) men. We further explored if these associations varied by the body mass index (BMI) and height. Methods. Age-matched DNA samples from 259 AAM and 269 EAM were genotyped for 10 candidate SNPs in 7 genes using the TaqMan allelic differentiation analysis. The dominant, recessive, and additive age-adjusted unconditional logistic regression models were fitted. Results. Three SNPs showed statistically significant associations with PCa risk: in AAM, HNF1B rs7501939 (OR = 2.42, P = 0.0046) and rs4430796 (OR = 0.57, P = 0.0383); in EAM, CTBP2 rs4962416 (OR = 1.52, P = 0.0384). In addition, high BMI in AAM (OR = 1.06, P = 0.022) and height in EAM (OR = 0.92, P = 0.0434) showed significant associations. Interestingly, HNF1B rs7501939 was associated with PCa exclusively in obese AAM (OR = 2.14, P = 0.0103). Conclusion. Our results suggest that variation in the HNF1B may influence PCa risk in obese AAM.

Aspirin use is associated with lower prostate cancer risk in male carriers of BRCA mutations

Previous studies have shown that male BRCA mutation carriers stand at increased risk of developing prostate cancer and have concerns about developing cancer. Genetic counseling practitioners often discuss strategies for reducing the risk of cancer for patients at high risk due to their genetic background. Addressing modifiable health habits is one such strategy. Unfortunately, modifiable risk factors for prostate cancer have only been documented in the general population and have not yet been studied in the BRCA carrier subpopulation. Therefore, this study aimed to identify modifiable risk factors for prostate cancer in BRCA carriers. We examined prostate cancer risk factors in 74 men who were part of families with a BRCA mutation. This study examined nine dichotomous variables including: exercise, history of vasectomy, smoking history, alcohol use, finasteride use, statin use, aspirin use, coffee use, and vitamin use. The survey was sent to all cases of prostate cancer in the Hereditary Cancer Center Database at Creighton University with a known BRCA status. This study confirmed the protective benefits of daily aspirin use, which have been observed in previous studies of the general population, and suggests its benefit in BRCA carriers. Protective benefits from regular vigorous exercise and daily coffee use trended towards significance, but neither factor withstood the Bonferroni Correction for multiple comparisons.

Invited commentary: are dietary intakes and other exposures in childhood and adolescence important for adult cancers?

In this issue of the Journal, Nimptsch et al. (Am J Epidemiol. 2013;178(2):172-183) report significant associations between female adolescents' poultry consumption in high school and subsequent reduced risk of colorectal adenomas in adulthood. Consumption of red meat or fish was not related to risk, but replacement with poultry reduced the risk of later adenomas. Most epidemiologic studies of adult diseases lack exposure data from the distant past. By focusing on a cancer precursor lesion and using a variety of methods to assess data quality, the investigators address concerns about the quality of distant recall. These findings add to the growing evidence that links childhood and adolescent lifestyle and environmental exposures with subsequent risk of cancers arising in adulthood. Highlights of the literature on this topic and methodological challenges are summarized. Future studies would benefit from incorporating measures of lifestyle, diet, environmental exposures, and other risk factors from early in life and from validation and other data quality checks of such measurements. Sources of historical data on children's and adolescents' exposures should be sought and evaluated in conjunction with subsequent exposures in relationship to adult-onset cancers.

Prostate cancer: is it time to expand the research focus to early-life exposures?

Although the contribution of lifestyle and environment (non-genetic factors) to prostate carcinogenesis is indicated by international variation in prostate cancer occurrence and migration studies, no conclusive modifiable risk factors have yet been identified. One possible reason for this may be the dearth of epidemiological research on exposures experienced early in life, when the immature prostate may be more susceptible to carcinogenic exposures. In this Opinion article, we summarize the rationale for studying early-life exposures, describe the small body of early-life research and its associated challenges, and point to solutions for future research.

Case-control study of lifetime alcohol intake and prostate cancer risk

PURPOSE

Alcohol consumption may be a modifiable risk factor for prostate cancer, but previous results have been inconsistent and limited by a lack of data on lifetime exposure and specific beverages. Furthermore, the effect of tumor stage and severity of disease on the association between alcohol and prostate cancer risk has not been fully investigated.

METHODS

We examined the relation between both current and lifetime alcohol intake and prostate cancer risk in a population-based case-control study in Alberta, Canada with 947 cases with stage T2 and higher prostate cancer diagnosed between 1997 and 2000 and frequency matched to 1,039 controls, identified through random digit dialing. Cases were classified on cancer stage and severity into 619 non-aggressive (Stage II and Gleason score <8) and 328 aggressive cases (Stage III/IV or Gleason score ≥8). In-person interviews were completed on current and lifetime history of alcohol consumption and all other prostate cancer risk factors.

RESULTS

Current alcohol intake did not increase prostate cancer risk but lifetime intake increased risk for both non-aggressive and aggressive cases, with an odds ratio of 1.78 (95 % CI 1.19-2.66) and 2.00 (95 % CI 1.19-3.36), respectively, for the highest intake quartile compared to non-drinkers with evidence for a linear trend. Associations with alcohol intake remained after exclusion of non-drinkers for non-aggressive prostate cancer cases. Only lifetime beer intake was significantly associated with increased risk, however, intakes of liquor and wine by participants were low.

CONCLUSIONS

Results support the evidence for an increased risk of prostate cancer from lifetime alcohol consumption.

Does physical activity reduce the risk of prostate cancer? A systematic review and meta-analysis

CONTEXT

Numerous observational epidemiologic studies have evaluated the association between physical activity and prostate cancer (PCa); however, the existing results are inconsistent.

OBJECTIVE

To determine the association between physical activity and risk of PCa.

EVIDENCE ACQUISITION

A systematic search was performed using the Medline, Embase, and Web of Science databases through 15 May 2011 to identify all English-language articles that examined the effect of physical activity on the risk of PCa. This meta-analysis was conducted according to the guidelines for the meta-analysis of observational studies in epidemiology.

EVIDENCE SYNTHESIS

This meta-analysis consisted of 88,294 cases from 19 eligible cohort studies and 24 eligible case-control studies. When data from both types of studies were combined, total physical activity (TPA) was significantly associated with a decreased risk of PCa (pooled relative risk [RR]: 0.90; 95% confidence interval [CI], 0.84-0.95). The pooled RR for occupational physical activity (OPA) and recreational physical activity (RPA) were 0.81 (95% CI, 0.73-0.91) and 0.95 (95% CI, 0.89-1.00), respectively. Notably, for TPA, we observed a significant PCa risk reduction for individuals between 20 and 45 yr of age (RR: 0.93; 95% CI, 0.89-0.97) and between 45 and 65 yr of age (RR: 0.91; 95% CI, 0.86-0.97) who performed activities but not for individuals <20 yr of age or >65 yr of age.

CONCLUSIONS

There appears to be an inverse association between physical activity and PCa risk, albeit a small one. Given that increasing physical activity has numerous other health benefits, men should be encouraged to increase their physical activity in both occupational and recreational time to improve their overall health and potentially decrease their risk of PCa.

Inhibitory effect of dietary atorvastatin and celecoxib together with voluntary running wheel exercise on the progression of androgen-dependent LNCaP prostate tumors to androgen independence

We determined the inhibitory effect of dietary atorvastatin, dietary celecoxib and voluntary running wheel exercise (RW) alone or in combination on the formation and growth of androgen-independent LNCaP tumors in castrated SCID mice. Male SCID mice were injected subcutaneously with androgen-dependent prostate cancer LNCaP cells. When the tumors reached a moderate size, the mice were surgically castrated and treated with atorvastatin (0.02% in the diet), celecoxib (0.05% in the diet) or RW alone or in combination for 42 days. RW or celecoxib alone had a moderate inhibitory effect on the androgen-independent growth of LNCaP tumors, but atorvastatin alone had little or no effect on tumor growth. Combinations of atorvastatin and celecoxib had a stronger inhibitory effect on the formation and growth of androgen-independent LNCaP tumors than either drug alone. A combination of RW together with atorvastatin and celecoxib had the most potent inhibitory effect on the progression of LNCaP tumors to androgen independent growth. The serum concentration of atorvastatin after two weeks of oral administration of atorvastatin was 6.1 ng/ml. The serum concentration of celecoxib after treatment with dietary celecoxib for two weeks was 1090 ng/ml. The serum concentration of atorvastatin but not that of celecoxib was substantially reduced when the two drugs were given in combination. The drug concentrations observed in our animal studies are comparable or less than those commonly found in humans treated with atorvastatin or celecoxib. Our results indicate that administration of atorvastatin and celecoxib together with voluntary exercise may be an effective strategy for the prevention of prostate cancer progression from androgen dependence to androgen independence.

State of the epidemiological evidence on physical activity and cancer prevention

BACKGROUND

Physical activity is a modifiable lifestyle risk factor that has the potential to reduce the risk of most major cancer sites.

METHODS

We examined the strength, consistency, dose-response and biological plausibility of an association between physical activity and risk of colon, breast, endometrium, lung, prostate, ovarian, gastric, rectal, pancreatic, bladder, testicular, kidney and haematological cancers. We also estimated the population-attributable risk (PAR) for physical inactivity and cancer in 15 European countries.

RESULTS

There is convincing or probable evidence for a beneficial effect of physical activity on the risk of colon, breast and endometrial cancers. The evidence is weaker for ovarian, lung and prostate cancers and generally either null or insufficient for all remaining cancers. Several hypothesised biological mechanisms include a likely effect of physical activity on insulin resistance, body composition, sex steroid hormones and a possible effect on vitamin D, adipokines, inflammation and immune function. Somewhere between 165,000 and 330,000 cases of the six major cancers (breast, colon, lung, prostate, endometrium and ovarian) could have been prevented in 2008 in Europe alone if the population had maintained sufficient levels of physical activity.

CONCLUSION

There is strong and consistent evidence that physical activity reduces the risk of several of the major cancer sites, and that between 9% and 19% of cancer cases could be attributed to lack of sufficient physical activity in Europe. Public health recommendations for physical activity and cancer prevention generally suggest 30-60 min of moderate or vigorous-intensity activity done at least 5d per week.

Metformin and the incidence of prostate cancer in patients with type 2 diabetes

BACKGROUND

Several in vitro studies have indicated that metformin may reduce the risk of prostate cancer; however, epidemiologic studies have been inconclusive. The objective of this study was to determine whether metformin decreases the risk of prostate cancer in patients with type 2 diabetes.

METHODS

A nested case-control analysis was conducted within a population-based cohort from the UK General Practice Research Database. The cohort included patients over the age of 40 who were prescribed a first oral hypoglycemic agent (OHA) between 1988 and 2009. Cases of prostate cancer were matched up to ten controls on year of birth, date of cohort entry, and duration of follow-up. Adjusted rate ratios (RR) were estimated using conditional logistic regression.

RESULTS

The cohort included 63,049 incident users of OHAs, in which 739 cases of prostate cancer were matched to 7,359 controls. Metformin use did not decrease the risk of prostate cancer (RR: 1.23, 95% CI: 0.99-1.52). In secondary analyses, prostate cancer risk was found to increase as a function of the number of metformin prescriptions received (one to seven prescriptions: RR: 1.05, 95% CI: 0.80-1.37; seven to eighteen prescriptions: RR: 1.29, 95% CI: 0.99-1.69; eighteen to thirty-six prescriptions: RR: 1.37, 95% CI: 1.04-1.81; more than thirty-six prescriptions: RR: 1.40, 95% CI: 1.03-1.89).

CONCLUSION

The results of this study indicate that metformin does not reduce the risk of prostate cancer in patients with type 2 diabetes.

IMPACT

The secondary analyses need to be interpreted with caution given the inverse association between type 2 diabetes and prostate cancer.

Lifetime trajectory of physical activity according to energy expenditure and joint force

OBJECTIVE

To develop and demonstrate the feasibility of a method for estimating lifetime hip and knee cumulative joint force using survey data on physical activity, and to construct and describe lifetime trajectories of energy expenditure and hip and knee joint force.

METHODS

Exposure data on lifetime physical activity, including type (occupational, household, and recreation) and dose (frequency, intensity, and duration), were collected from a Canada-wide population study of adults ages ≥45 years. Subjects were ranked in 2 ways: in terms of physical activity-related energy expenditure and in terms of a cumulative peak force index (CPFI) for the hip and knee, which is a measure of lifetime exposure and is a time/joint force product involving years of force and subject bodyweight. A relative joint loading index was calculated as the ratio of joint force (CPFI score) to energy expenditure.

RESULTS

A total of 4,269 subjects completed the baseline measurements. Lifetime energy expenditure and hip and knee CPFI scores were higher for occupational and household activity than sport. The mean lifetime energy expenditure from total physical activity in the study sample was 119.1 metabolic equivalent-hours/week. Women had slightly higher total lifetime energy expenditure and CPFI scores than men. The relative joint loading index was highest for male household and sport activity and lowest for female occupational activity.

CONCLUSION

Lifetime cumulative hip/knee joint force trajectories were successfully constructed from survey data and followed expected trends. Comparing energy expenditure with joint force revealed variation by age, sex, and activity type, indicating these measures may help distinguish the numerous benefits of physical activity from possible risks.

Case-control study of lifetime total physical activity and endometrial cancer risk

A population-based case–control study of physical activity and endometrial cancer risk was conducted in Alberta between 2002 and 2006. Incident, histologically confirmed cases of endometrial cancer (n = 542) were frequency age-matched to controls (n = 1,032). The Lifetime Total Physical Activity Questionnaire was used to measure occupational, household, and recreational activity levels. Multivariable logistic regression analyses were conducted. Total lifetime physical activity reduced endometrial cancer risk (odds ratio [OR] for >129 vs. <82 MET-h/week/year = 0.86, 95% confidence interval [95% CI]: 0.63, 1.18). By type of activity, the risks were significantly decreased for greater recreational activity (OR = 0.64, 95% CI: 0.47, 0.87), but not for household activity (OR = 1.09, 95% CI: 0.75, 1.58) and/or occupational activity (OR = 0.90, 95% CI: 0.67, 1.20) when comparing the highest to lowest quartiles. For activity performed at different biologically defined life periods, some indication of reduced risks with activity done between menarche and full-term pregnancy and after menarche was observed. When examining the activity by intensity of activity (i.e., light <3, moderate 3–6, and vigorous >6 METs), light activity slightly decreased endometrial cancer risk (OR = 0.68, 95% CI: 0.48, 0.97) but no association with moderate or vigorous intensity activity was found. Endometrial cancer risk was increased with sedentary occupational activity by 28% (95 CI%: 0.89, 1.83) for >11.3 h/week/year versus ≤2.4 h/week/year or by 11% for every 5 h/week/year spent in sedentary behavior. This study provides evidence for a decreased risk between lifetime physical activity and endometrial cancer risk and a possible increased risk associated with sedentary behavior.

Physical activity and genitourinary cancer prevention

The present review of epidemiologic studies of physical activity and genitourinary cancers (prostate, bladder, renal cell, and testicular cancers) suggests a weak inverse relation of physical activity to risk of prostate and renal cell cancer, with average risk decreases of less than 10% comparing high versus low levels of physical activity. For prostate cancer, studies that assessed activity intensity or those that considered fatal prostate cancer as a study endpoint produced the strongest inverse association. For renal cell cancer, the inverse relation with physical activity was more apparent among women than men, among normal weight than overweight or obese individuals, and among older than younger individuals. In contrast to prostate and renal cell cancer, available data show that physical activity is not associated with bladder or testicular cancer. Future research should include improvements in self-reported activity measures and incorporation of objective assessments of physical activity over the life course in order to more precisely characterize types, parameters, and timing of physical activity in relation to genitourinary cancers. Also, data are lacking regarding whether fitness potentially influences genitourinary cancer risk. The relation of physical activity and fitness to genitourinary cancer prognosis and survival requires specific attention. Mechanistic research should identify the underlying biologic pathways potentially linking physical activity to genitourinary cancers.

Age-specific physical activity and prostate cancer risk among white men and black men

BACKGROUND

: The relation of physical activity across the lifespan to risk of prostate cancer has not been thoroughly investigated, particularly among black men. The authors investigated physical activity, including activity during different age periods and of various intensities, in relation to prostate cancer incidence among white men and black men.

METHODS

: In total, 160,006 white men and 3671 black men ages 51 years to 72 years who were enrolled in the National Institutes of Health-AARP Diet and Health Study reported their time spent per week engaging in physical activity during ages 15 to 18 years, 19 years to 29 years, 35 years to 39 years, and during the past 10 years. Cox regression models were used to examine physical activity, categorized by intensity (moderate or vigorous, light, and total), in relation to prostate cancer risk.

RESULTS

: During 7 years of follow-up, 9624 white men and 371 black men developed prostate cancer. Among white men, physical activity had no association with prostate cancer regardless of age period or activity intensity. Among black men, engaging in > or =4 hours of moderate/vigorous intensity physical activity versus infrequent activity during ages 19 years to 29 years was related to a 35% lower risk of prostate cancer (relative risk, 0.65; 95% confidence interval [95% CI], 0.43-0.99 [P(trend) = .01]). Frequent moderate/vigorous physical activity at ages 35 years to 39 years also potentially was related to reduced prostate cancer risk (relative risk, 0.59; 95% CI, 0.36-0.96 [P(trend) = .15]).

CONCLUSIONS

: Regular physical activity may reduce prostate cancer risk among black men, and activity during young adulthood may yield the greatest benefit. This novel finding needs confirmation in additional studies. Cancer 2009. Published 2009 by the American Cancer Society.

A prospective study of lifetime physical activity and prostate cancer incidence and mortality

Background:

The possible benefit of lifetime physical activity (PA) in reducing prostate cancer incidence and mortality is unclear.

Methods:

A prospective cohort of 45 887 men aged 45–79 years was followed up from January 1998 to December 2007 for prostate cancer incidence (n=2735) and to December 2006 for its subtypes and for fatal (n=190) prostate cancer.

Results:

We observed an inverse association between lifetime (average of age 30 and 50 years, and baseline age) total PA levels and prostate cancer risk. Multivariate-adjusted incidence in the top quartile of lifetime total PA decreased by 16% (95% confidence interval (CI)=2–27%) compared with that in the bottom quartile. We also observed an inverse association between average lifetime work or occupational activity and walking or bicycling duration and prostate cancer risk. Compared with men who mostly sit during their main work or occupation, men who sit half of the time experienced a 20% lower risk (95% CI=7–31%). The rate ratio linearly decreased by 7% (95% CI=1–12%) for total, 8% (95% CI=0–16%) for localised and 12% (95% CI=2–20%) for advanced prostate cancer for every 30 min per day increment of lifetime walking or bicycling in the range of 30 to 120 min per day.

Conclusions:

Our results suggest that not sitting for most of the time during work or occupational activity and walking or bicycling more than 30 min per day during adult life is associated with reduced incidence of prostate cancer.

Physical activity reduces prostate carcinogenesis in a transgenic model

BACKGROUND

Several epidemiological studies have reported an inverse association between physical activity and the risk of prostate cancer. To date, there are few animal studies looking at physical activity and cancer incidence, although the results are consistent with the epidemiological evidence. In general, as exercise intensity increased in the rats/mice, the likelihood that physical activity inhibited carcinogenesis increased.

METHODS

The present study used voluntary wheel running with C3(1)Tag mice that are predisposed to prostate cancer due to the directed expression of SV40 oncogenes. After 10 weeks, the prostates were collected from run and non-run mice and histopathology performed for the presence or absence of low grade or high grade PINS.

RESULTS

We found that for those mice that ran >5Km/group, 83% of the dorsolateral prostates were classified as within normal levels vs. 43% for the <5 km/day group (p = 0.16). In addition, there was a relationship between average distance run and pathologic progression to high-grade PIN and local invasion, considered to be an early event in the formation of prostate adenocarcinoma. Forty three percent of dorsalateral prostates from mice that ran less than 5 km/day were classified with advanced pathology as compared to none (0) in mice that ran more than 5.0 km/day (p = 0.05).

CONCLUSIONS

The results presented herein indicate that prostatic cancer progression is likely delayed or diminished by wheel running activity in a dose dependent manner in transgenic mice. These findings provide further evidence that exercise acts to decrease the progression of prostate cancer and they establish a transgenic animal model for future studies to define mechanism(s). Prostate 69: 1372-1377, 2009. (c) 2009 Wiley-Liss, Inc.

Exercise therapy across the prostate cancer continuum

Exercise has been increasingly investigated as an adjunct therapy for cancer patients. The purpose of this paper is to comprehensively review the literature regarding exercise as a therapeutic adjunct for prostate cancer (PC). Several studies in patients with PC have shown quality of life improvements associated with exercise. Although no study has established the effect of exercise as a monotherapy for PC, the molecular mechanisms responsible for the potential association between exercise and PC are being elucidated. Given the low-risk, high-reward nature of these studies, further investigations are needed to better define the function of exercise along the PC continuum.