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.

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.

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.

Prostate cancer is a leading cause of cancer morbidity and mortality in men. In addition to improved treatments, strategies to reduce disease risk are urgently required. This review summarises the literature that examines the association between exercise and prostate cancer risk. Between 1989 and 2001, 13 cohort studies were conducted in the US and internationally. Of these, nine showed an association between exercise and decreased prostate cancer risk. Five of 11 case-control studies conducted between 1988 and 2002 reported an association between decreased risk of prostate cancer and high activity levels. Considering all studies performed between 1976 and 2002, 16 out of 27 studies reported reduced risk in men who were most active; in nine out of 16 studies the reduction in risk was statistically significant. Average risk reduction ranged from 10-30%. In aggregate, this evidence suggests a probable link between increased physical exercise and decreased prostate cancer risk. The ability of exercise to modulate hormone levels, prevent obesity, enhance immune function and reduce oxidative stress have all been postulated as mechanisms that may underlie the protective effect of exercise. Exercise may also be of benefit in men undergoing treatment for prostate cancer. Overall, study design and control of potential confounding factors varied greatly among studies, possibly contributing to the variation in results. Epidemiological studies that are better controlled, larger in scale and more carefully designed may help to more fully clarify the relationship between exercise and prostate cancer. In addition, intervention trials that test whether exercise programmes can reduce prostate cancer risk are currently underway to rigorously test the ability of exercise to reduce prostate cancer incidence.

Physical activity has been studied in relation to prostate cancer risk, but the findings have been inconclusive. We prospectively examined the association between self-reported recreational physical activity and overall risk of prostate cancer, risk of advanced disease and risk of prostate cancer death in a cohort of 29,110 Norwegian men. Incident prostate cancers were obtained from the Norwegian Cancer Registry, and prostate cancer deaths were obtained from the national Cause of Death Registry. During 17 years of follow-up, 957 incident cases were identified, 266 of them were advanced (i.e. metastases at diagnosis) and 354 of the incident cases died from prostate cancer. In multivariable analysis, frequency and duration of exercise were inversely associated with the risk of advanced prostate cancer (p for trend = 0.04 and 0.02). We computed a summary score that combined frequency, duration and intensity of exercise, and this score showed inverse associations with advanced prostate cancer risk and mortality (p for trend = 0.02 and 0.07). Compared to men who reported no activity, the relative risks (95% confidence intervals) among men in the highest category of physical exercise was 0.64 (0.43-0.95) for advanced prostate cancer and 0.67 (0.48-0.94) for prostate cancer death. We found no association between physical activity and overall risk of prostate cancer. We conclude that recreational physical exercise is associated with reduced risk of advanced prostate cancer and prostate cancer death.

Purpose: Research on the association between physical activity and the risk of prostate cancer is inconsistent. The aim of this study was to investigate whether the timing, intensity, and type of recreational physical activity influence prostate cancer risk.

Methods: A population-based case-control study was conducted in Western Australia in 2001-2002. Data were collected on lifetime recreational physical activity from a self-reported questionnaire. The estimated effects of recreational physical activity on prostate cancer risk were analyzed using logistic regression, adjusting for demographic and lifestyle factors. This analysis included 569 incident cases and 443 controls.

Results: There was a significant, inverse dose-response relationship between vigorous-intensity recreational physical activity between the ages 19 and 34 years and the risk of prostate cancer (p = 0.013). Participants in the most active quartile of vigorous-intensity physical activity in this age period had a 33% lower risk of prostate cancer than participants in the least active quartile (Adjusted Odds Ratio = 0.67, 95% confidence interval = 0.45-1.01). Moderate-intensity recreational physical activity was not associated with the risk of prostate cancer. Recreational physical activity performed over the lifetime showed no association with prostate cancer risk. Weight training performed from early adulthood onwards showed a non-significant but consistent inverse association with prostate cancer risk. There was no strong evidence that physical activity was differentially associated with the risks of low-grade and medium-to-high grade prostate cancers.

Conclusions: A high level of vigorous recreational physical activity in early adulthood may be required to reduce the risk of prostate cancer.

Effect modification by smoking status was not observed for other smoking-related cancers such as head and neck cancer. This provides some evidence against a generic bias due to residual confounding by smoking, although case numbers were too small to rule this out definitively. For myeloma, smoking is not a risk factor and effect modification may therefore be due to small case numbers and/or chance.

Leisure-time physical activity was positively associated with prostate cancer risk, but there is no known biologic rationale to explain this association. Physically active men are more likely than inactive men to receive digital rectal examinations and/or prostate-specific antigen screening, which increases the likelihood of diagnosing indolent prostate cancers. The positive association that we observed could therefore be due to screening bias. To circumvent this potential bias, we analyzed advanced prostate cancers in the NIH-AARP study because advanced cases are less likely to remain indolent, and found no association between physical activity and advanced prostate cancer. This difference in associations for overall prostate cancers and advanced prostate cancers implies that results for overall prostate cancers were influenced by screening bias, although we cannot fully rule out etiologic heterogeneity.

The higher risk of melanoma with increased leisure-time physical activity was notable, particularly because this association has only been examined in 1 prior study. This case-control study found that higher activity levels were associated with a 30% lower melanoma risk, a finding that our analysis refutes. Of the 12 cohorts we examined, 8 found higher activity levels to be associated with at least a 20% higher melanoma risk. Greater incidental sun exposure seems to be the likely reason for this increase in melanoma risk because physical activity is frequently done outdoors in light clothing and has been associated with substantially increased risk of sunburn. Moreover, we found that the physical activity–melanoma association was stronger in high-UV areas, implying that sun exposure is an important factor underlying this association. Physically active people thus appear to be a vulnerable population for melanoma, and cancer prevention efforts focused on physical activity should emphasize sun exposure safety (eg, http://www.cancer.org/healthy/besafeinthesun/ ).

The evidence concerning the possible association between physical activity and the risk of prostate cancer is inconsistent and additional data are needed. We examined the association between risk of prostate cancer and physical activity at work and in leisure time in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. In our study, including 127,923 men aged 20-97 years from 8 European countries, 2,458 cases of prostate cancer were identified during 8.5 years of followup. Using the Cox proportional hazards model, we investigated the associations between prostate cancer incidence rate and occupational activity and leisure time activity in terms of participation in sports, cycling, walking and gardening; a metabolic equivalent (MET) score based on weekly time spent on the 4 activities; and a physical activity index. MET hours per week of leisure time activity, higher score in the physical activity index, participation in any of the 4 leisure time activities, and the number of leisure time activities in which the participants were active were not associated with prostate cancer incidence. However, higher level of occupational physical activity was associated with lower risk of advanced stage prostate cancer (p(trend) = 0.024). In conclusion, our data support the hypothesis of an inverse association between advanced prostate cancer risk and occupational physical activity, but we found no support for an association between prostate cancer risk and leisure time physical activity.

Purpose: Bicycle riding is one of the most popular means of transportation, recreation, fitness and sports among millions of people of all ages who ride on road and off road, using a variety of bicycle types. It is also a readily available form of aerobic non-impact exercise with established cardiovascular beneficial effects. Bicycles are also a common source of significant injuries. This review focuses upon the specific bicycling related overuse injuries affecting the genitourinary tract.

Materials And Methods: MEDLINE search of the literature on bicycling and genitourinary disorders was performed using multiple subject headings and additional keywords. The search yielded overall 62 pertinent articles. We focused primarily on the most prevalent related disorders such as pudendal nerve entrapment, erectile dysfunction and infertility. The potential effect of bicycling on serum PSA level was also discussed in depth in view of its recognized clinical importance. Infrequent disorders, which were reported sporadically, were still addressed, despite their rarity, for the comprehensiveness of this review.

Results: The reported incidence of bicycling related urogenital symptoms varies considerably. The most common bicycling associated urogenital problems are nerve entrapment syndromes presenting as genitalia numbness, which is reported in 50-91% of the cyclists, followed by erectile dysfunction reported in 13-24%. Other less common symptoms include priapism, penile thrombosis, infertility, hematuria, torsion of spermatic cord, prostatitis, perineal nodular induration and elevated serum PSA, which are reported only sporadically.

Conclusions: Urologists should be aware that bicycling is a potential and not an infrequent cause of a variety of urological and andrological disorders caused by overuse injuries affecting the genitourinary system.

Background: Recent literature has suggested that bicycling may be associated with increases in serum PSA levels, a diagnostic and prognostic marker for prostate cancer. To further investigate this relationship, we conducted a systematic review and meta-analysis of current literature in this field.

Methods: MEDLINE, CENTRAL, CINAHL and SPORTDiscus were searched using MeSH terms and keywords for English publications related to bicycle riding and PSA. Studies were included if PSA was measured relative to cycling activity in healthy men who were free of any prostatic condition. Case studies were excluded.

Results: Eight studies met our inclusion criteria, comprising 912 participants that engaged in, or self-reported, bicycling activity. Six studies investigated the acute pre-post change in PSA following bicycling activity that ranged from a single cycling bout of 15 min to a 4-day cycling event. Following cycling activity, two studies reported total PSA increased from baseline by up to 3.3-fold, free PSA increased in one study by 0.08±0.18 ng ml(-)(1) and did not change in four studies. One study compared PSA in elite/professional cyclists versus non-cyclists and demonstrated no significant difference in PSA measurements between groups. Data from six studies were meta-analyzed and demonstrated no significant increase in PSA associated with cycling from pre to post (mean change +0.027 ng ml(-)(1), s.e.m.=0.08, P=0.74, 95% confidence interval (CI)=-0.17-0.23).

Conclusions: Our findings suggest that there is no effect of cycling on PSA; however, the limited number of trials and the absence of randomized controlled trials limit the interpretation of our results. Additionally, the median sample size only consisted of 42 subjects. Therefore, our study may have low statistical power to detect a difference in PSA. Although, a higher sample size may demonstrate statistical significance, it may not be clinically significant. Studies of higher empirical quality are needed.