Cardiorespiratory fitness and risk of site-specific cancers: a long-term prospective cohort study

Unraveling the link between cardiorespiratory fitness and cancer: a state-of-the-art review

Cardiorespiratory fitness (CRF) not only reflects an individual's capacity to perform physical activities but also encapsulates broader effects on the basic biology of aging. This review aims to summarize the evidence on the influence of CRF on overall and site-specific cancer risks. It delves into the biological mechanisms through which CRF may exert its effects, explores the clinical implications of these findings, identifies gaps in the current evidence base, and suggests directions for future research. The synthesis of findings reveals that higher CRF levels (general threshold of > 7 METs) are consistently associated with a reduced risk of a range of cancers, including head and neck, lung, breast, gastrointestinal, particularly pancreatic and colorectal, bladder, overall cancer incidence and mortality, and potentially stomach and liver, bile duct, and gall bladder cancers. These inverse associations between CRF and cancer risk do not generally differ across age groups, sex, race, or adiposity, suggesting a universal protective effect of CRF. Nonetheless, evidence linking CRF with skin, mouth and pharynx, kidney, and endometrial cancers is limited and inconclusive. Conversely, higher CRF levels may be potentially linked to an increased risk of prostate cancer and hematological malignancies, such as leukemia and myeloma, although the evidence is still not conclusive. CRF appears to play a significant role in reducing the risk of several cancers through various biological mechanisms, including inflammation reduction, immune system enhancement, hormonal regulation, and metabolic improvements. Overall, enhancing CRF through regular physical activity offers a vital, accessible strategy for reducing cancer risk and extending the health span. Future research should aim to fill the existing evidence gaps regarding specific cancers and elucidate the detailed dose-response relationships between CRF levels and cancer risk. Studies are also needed to elucidate the causal relationships and mechanistic pathways linking CRF to cancer outcomes.

Cardiorespiratory fitness is a strong and consistent predictor of morbidity and mortality among adults: an overview of meta-analyses representing over 20.9 million observations from 199 unique cohort studies

OBJECTIVE

To examine and summarise evidence from meta-analyses of cohort studies that evaluated the predictive associations between baseline cardiorespiratory fitness (CRF) and health outcomes among adults.

DESIGN

Overview of systematic reviews.

DATA SOURCE

Five bibliographic databases were searched from January 2002 to March 2024.

RESULTS

From the 9062 papers identified, we included 26 systematic reviews. We found eight meta-analyses that described five unique mortality outcomes among general populations. CRF had the largest risk reduction for all-cause mortality when comparing high versus low CRF (HR=0.47; 95% CI 0.39 to 0.56). A dose-response relationship for every 1-metabolic equivalent of task (MET) higher level of CRF was associated with a 11%-17% reduction in all-cause mortality (HR=0.89; 95% CI 0.86 to 0.92, and HR=0.83; 95% CI 0.78 to 0.88). For incident outcomes, nine meta-analyses described 12 unique outcomes. CRF was associated with the largest risk reduction in incident heart failure when comparing high versus low CRF (HR=0.31; 95% CI 0.19 to 0.49). A dose-response relationship for every 1-MET higher level of CRF was associated with a 18% reduction in heart failure (HR=0.82; 95% CI 0.79 to 0.84). Among those living with chronic conditions, nine meta-analyses described four unique outcomes in nine patient groups. CRF was associated with the largest risk reduction for cardiovascular mortality among those living with cardiovascular disease when comparing high versus low CRF (HR=0.27; 95% CI 0.16 to 0.48). The certainty of the evidence across all studies ranged from very low-to-moderate according to Grading of Recommendations, Assessment, Development and Evaluations.

CONCLUSION

We found consistent evidence that high CRF is strongly associated with lower risk for a variety of mortality and incident chronic conditions in general and clinical populations.

Cardiorespiratory Fitness and Incidence of Digestive System Cancers in Men

PURPOSE

To assess the association between cardiorespiratory fitness (CRF) and incidence of digestive system cancers (DSCs) in men.

METHODS

A prospective cohort of 4,540 men aged 55.2 ± 13.1 years who were free from malignancy at baseline was studied. Exposure was CRF quantified from treadmill exercise testing (individualized ramp protocol) in metabolic equivalents (METs). Incidence of DSCs was the primary outcome, utilizing medical records of any new diagnosed DSC. Cox proportional hazard analyses were conducted adjusting for established cancer risk factors.

RESULTS

Mean CRF was 8.3 ± 3.5 METs. During 13 ± 7.6 years follow up, 250 (5.5%) DSC cases were diagnosed (colorectal = 163, gallbladder = 46, liver = 23, esophagus = 8, pancreas = 7 and other digestive organ cancers = 3). For each 1-MET increase in CRF there were 6% [Hazard Ratio = 0.94, 95% CI (0.91-0.98), p = 0.006], and 9% [Hazard Ratio = 0.91, 95% CI (0.85-0.97), p = 0.006] lower risks of DSC incidence in the total cohort and among men younger than 60 years old, respectively. Additionally, each 1-MET increase in CRF was associated with 9% lower risks of DSC incidence among never and current smokers. CRF was not associated with DSC incidence among men ≥ 60 years old and among former smokers.

CONCLUSION

Higher CRF was associated with lower risk of DSC incidence in men, particularly in those younger than 60 years, and never and current smokers. These findings suggest that higher CRF has potential preventive benefits against the development of DSCs, although additional large studies are needed. CRF screening and achieving higher levels could serve as a complementary preventive strategy for public health.

Impact of Physical Exercise on Melanoma Hallmarks: Current Status of Preclinical and Clinical Research

In recent years, accumulating evidence from preclinical and clinical studies consistently indicated that physical activity/exercise plays a crucial role in reducing the incidence and recurrence of various malignancies, by exerting a beneficial modulation of cancer hallmarks. Moreover, physical activity is suggested to attenuate certain adverse effects of anticancer therapy, including the reduction of cardiovascular toxicity and symptoms related to depression and anxiety, among others, while preserving muscular strength. In the case of melanoma, the relationship with physical activity has been critically debated. Historically, several cohort studies and meta-analyses reported a positive association between physical activity/exercise and melanoma risk. This association was primarily attributed to outdoor activities that may expose the skin to UV radiation, a well-known risk factor for melanocyte transformation. However, more recent evidence does not support such association and recognizes physical activity/exercise role in both melanoma prevention and progression. Nevertheless, sun protection is recommended during outdoor training to minimize UV radiation exposure. This narrative review summarizes preclinical and clinical data about physical activity effects on melanoma hallmarks. Specifically, experimental evidence is reported concerning (i) invasion and metastasis, (ii) reprogramming of energy metabolism, (iii) angiogenesis, (iv) resistance to cell death, (v) evasion from immune destruction, and (vi) tumor-promoting inflammation.

Non-exercise estimated cardiorespiratory fitness and cancer incidence: The NIH-AARP diet and health study

BACKGROUND

Non-exercise estimated cardiorespiratory fitness (NEE-CRF) has been shown to be associated with mortality, although its association with cancer incidence is unknown. The study aimed to assess the prospective association between NEE-CRF and cancer incidence in a large cohort of men and women.

METHODS

The National Institutes of Health-American Association of Retired Persons diet and health study is a prospective cohort that included 402,548 participants aged 50-71 years who were free from cancer at baseline (1995-1996) (men (n = 238,835) and women (n = 163,713)) and were followed until December 31, 2015. The exposure variable was NEE-CRF expressed in metabolic equivalents. NEE-CRF was estimated using a validated equation of self-reported predictors on demographics and lifestyle behaviors derived from baseline questionnaires. Primary outcomes were total cancer incidence and incidence of prostate, breast, lung, and colorectal cancers. Cox proportional hazards models were analyzed for the association between NEE-CRF and cancer incidence outcomes adjusted for established cancer risk factors.

RESULTS

During 13.7 ± 3.2 years of follow-up (mean ± SD), 64,344 men and 31,315 women developed a new cancer. For every 1-metabolic equivalent higher NEE-CRF, the hazard ratios and 95% confidence intervals (95%CIs) were 0.96 (95%CI: 0.94-0.97) and 0.88 (95%CI: 0.84-0.92) of total and colorectal cancer incidence among men, and 0.95 (95%CI: 0.93-0.97) and 0.94 (95%CI: 0.91-0.97) of total and breast cancer incidence among women, respectively (all p < 0.001). NEE-CRF was not associated with incidence of prostate and lung cancers in men or colorectal and lung cancers in women.

CONCLUSION

These results suggest that higher CRF levels, as assessed by the applied non-exercise estimated method, may provide preventive benefits against the development of cancer, while low CRF could potentially serve as a modifiable cancer risk factor. Integrating NEE-CRF into screening paradigms and referring low-fit individuals to improve CRF could complement the public health prevention strategy against cancer.

Physical activity, obesity, and bladder cancer incidence

PURPOSE

Cigarette smoking is an established risk factor for bladder cancer (BC), but evidence for physical inactivity and obesity is limited.

METHODS

This analysis included 146,027 participants from the Cancer Prevention Study-II (CPS-II) Nutrition Cohort, a large prospective cohort of cancer incidence established in 1992. Multivariable-adjusted Cox proportional hazards models were used to examine associations between body mass index (BMI), moderate-to-vigorous intensity aerobic physical activity (MVPA), leisure-time spent sitting, and BC risk. Effect modification by stage, smoking status, and sex was examined.

RESULTS

Only participants accumulating 15.0- < 30.0 MET-hrs/wk of MVPA had a lower risk of BC overall (RR 0.88, 95% CI 0.78, 0.99, compared to > 0-7.5 MET-hrs/wk) in the fully adjusted models. When stratifying on BC stage, MVPA (15- < 30 MET-hrs/wk vs. > 0- < 7.5 MET-hrs/wk, RR 0.83, 95% CI 0.70-0.99) and excess sitting time (≥ 6 h/day vs. 0- < 3 h/day RR 1.22, 95% CI 1.02, 1.47) were associated with risk of invasive BC only. There was no consistent evidence for effect modification by smoking status or sex.

CONCLUSION

This study supports that MVPA and sitting time may play a role in BC incidence, but associations likely differ by stage at diagnosis. While additional studies are needed to confirm associations by stage, this study adds to the evidence of the importance of being physically active for cancer prevention.

Physical Activity and Cardiorespiratory Fitness as Modulators of Health Outcomes: A Compelling Research-Based Case Presented to the Medical Community

The beneficial health effects and prognostic significance of regular moderate-to-vigorous physical activity (PA), increased cardiorespiratory fitness (CRF), or both are often underappreciated by the medical community and the patients they serve. Individuals with low CRF have higher annual health care costs, higher rates of surgical complications, and are two to three times more likely to die prematurely than their fitter counterparts when matched for risk factor profile or coronary calcium score. Increased levels of habitual PA before hospitalization for acute coronary syndromes are also associated with better short-term cardiovascular outcomes. Accordingly, this review examines these relations and the potential underlying mechanisms of benefit (eg, exercise preconditioning), with specific reference to the incidence of cardiovascular, cancer, and coronavirus diseases, and the prescriptive implications and exercise thresholds for optimizing health outcomes. To assess the evidence supporting or refuting the benefits of PA and CRF, we performed a literature search (PubMed) and critically reviewed the evidence to date. In aggregate, these data are presented in the context of clarifying the impact that regular PA and/or increased CRF have on preventing and treating chronic and infectious diseases, with reference to evidence-based exercise thresholds that the medical community can embrace and promote.

Estimated cardiorespiratory fitness in relation to overall, breast and prostate cancer incidence: the Norwegian HUNT study

PURPOSE

To investigate the relationships between the estimated cardiorespiratory fitness (eCRF) and the incidence of overall, breast, and prostate cancer in a large prospective cohort study.

METHODS

We included 46,968 cancer-free adults who participated in the second survey of the Trøndelag Health Study in Norway. Sex-specific non-exercise algorithms were used to estimate CRF. eCRF was classified into sex and age-specific tertiles, that is, into low, medium and high levels. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over a median of 22.1 years' follow-up, there were 7752 overall, 858 breast and 1376 prostate cancer cases. Medium and high levels of eCRF were associated with a reduced incidence of overall cancer in a dose-response manner in all participants (HR 0.96; 95% CI, 0.90-1.01 and HR 0.85; 95% CI, 0.79-0.91, respectively, and P-value for trend <.001). No association was observed between eCRF and breast cancer incidence in women. Only the high level of eCRF seemed to be associated with a reduced incidence of prostate cancer in men (HR 0.85; 95% CI, 0.72-1.02).

CONCLUSIONS

eCRF may be a practical and cost-effective means of investigating the association between the CRF and cancer incidence.

Life-Course Trajectories of Physical Activity and Melanoma Risk in a Large Cohort of Norwegian Women

Purpose

Physical activity (PA) is a cornerstone in disease prevention and varies throughout life. A pooled analysis of cohort studies and a meta-analysis of cohort studies found positive associations between PA and melanoma risk. However, previous studies focused on PA at specific ages and often lacked information on ultraviolet radiation (UVR) exposure. Using the population-based Norwegian Women and Cancer (NOWAC) cohort, including information on PA and UVR exposure, we estimated life-course PA trajectories from adolescence to adulthood and their associations with melanoma.

Methods

Total PA across different domains (recreation, occupation, transport, household) was reported for ages 14 and 30 years, and when responding to the questionnaire (31-76 years) using a 10-point scale, validated to rank PA levels in Norwegian females. We estimated life-course PA trajectories using a latent class mixed model in 152,248 women divided into three subcohorts depending on age at questionnaire completion: 31-39 (n = 27,098), 40-49 (n = 52,515) and ≥50 years (n = 72,635). The unique 11-digit identity number of Norwegian citizens was used to link NOWAC to the Cancer Registry of Norway for information on cancer diagnoses, emigration and death. Associations between PA trajectories and melanoma risk were estimated in each subcohort using multivariable Cox regression.

Results

Five classes of individual life-course PA trajectories were identified in subcohort 31-39 years (low, moderate, high, decreasing, increasing PA) and four in subcohorts 40-49 and ≥50 years (low, moderate, high, decreasing PA). No significant association was found between life-course PA trajectories and melanoma risk in any subcohort. Hazard ratios (95% confidence intervals) for the high versus moderate trajectory were 0.92 (0.66-1.29), 1.15 (0.97-1.37) and 0.90 (0.78-1.05) for subcohorts 31-39, 40-49 and ≥50 years, respectively.

Conclusion

Our results do not support a positive association between PA and melanoma risk found in previous studies, which is important for public health guidelines promoting regular PA.

Physical activity and cutaneous melanoma risk: A Norwegian population-based cohort study

Physical activity (PA) is an important factor in cancer prevention, but positive association between PA and risk of cutaneous melanoma found in recent studies may complicate this strategy. Ultraviolet radiation (UVR) exposure during outdoor PA is a plausible explanation for a positive association. We investigated the associations between PA, UVR and melanoma risk in the Norwegian Women and Cancer cohort. Overall PA was reported by 151,710 women, aged 30-75 at inclusion, using a validated 10-point-scale at enrolment and during follow-up, together with recent numbers of sunburns, indoor tanning sessions and weeks on sunbathing vacations. Seasonal outdoor walking and seasonal PAs were recorded in subsamples (n = 102,671 and n = 29,077, respectively). Logistic and Cox regression were used. Mean follow-up was 18.5 years, and 1565 invasive incident melanoma cases were diagnosed. Overall PA was inversely associated with sunburns, while positively associated with sunbathing vacations and indoor tanning. Overall PA was not associated with melanoma risk in all body sites combined (ptrend = 0.61), but reduced risk was found in upper limb melanomas (hazard ratio (HR) = 0.70, 95% confidence interval (CI) 0.51-0.96; high versus low PA). Non-significant reduced risks were found for seasonal outdoor walking >2 h/day versus 30-60 min/day (summer HR = 0.81, 95% CI 0.66-1.00; autumn HR = 0.74, 95%CI 0.55-1.01). Seasonal PAs were not associated with melanoma risk. In conclusion, we found positive associations between overall PA and sunbathing vacations and indoor tanning, and, unlike literature, inverse association between overall PA and sunburns. Our results do not support a positive association between PA and melanoma risk in Norwegian women.

Prevalence of Colorectal Polyps Based on Cardiorespiratory Fitness, Muscle Strength, Health Behavior, and Abdominal Obesity in Asymptomatic Elderly

Colorectal polyps are precursor lesions of colorectal cancer and are known to be associated with obesity, low physical activity, and unhealthy behavior. This cross-sectional study analyzed the prevalence of colorectal polyps based on cardiorespiratory fitness (CRF), muscle strength, and health behavior in older adults. Participants were asymptomatic and included 1024 men and 472 women aged 65-80 years who visited the health care center. Colonoscopy was performed under conscious sedation, and cardiorespiratory fitness was measured as the maximum oxygen uptake using gas analysis. Muscle strength was determined using isokinetic equipment, and physical activity, alcohol consumption, and smoking status were investigated using questionnaires. Waist circumference was measured at the thickest part of the middle of the abdomen. Logistic regression analysis was used to calculate the prevalence of colorectal polyps using odds ratios (ORs) based on the variables. The incidence of colorectal polyps was 65.2% in men and 48.5% in women. The ORs of colorectal polyps for obesity were 1.151 (95% confidence interval [CI], 1.010-2.291) and 1.178 (95% CI, 1.015-2.612) in men and women, respectively. The OR for colorectal polyps in male current smokers was 1.884. The ORs for low CRF were 1.985 and 1.841 in men and women, respectively, compared with high CRF. The prevalence of polyps increased with low muscle strength (men's OR 1.343 women's OR 1.440) and physical activity in both men (OR 1.693) and women (OR 1.861). In conclusion, lower CRF and muscle strength were associated with an increased prevalence of colorectal polyps in men and women. In both sexes, high waist circumference and low physical activity increased the prevalence of colorectal polyps.

The Impact of Physical Activity on Risk and Health-Related Quality of Life in Bladder Cancer

BACKGROUND: Sedentarism is an important modifiable risk factor in the struggle against cancer. In the last decades, the relationship between physical activity and different types of cancer has been investigated in depth. OBJECTIVE: To provide an overview of the literature on the effectiveness of physical activity in reducing the risk to develop bladder cancer and improving health-related quality of life in patients. METHODS: A systematic review was conducted through a search of the Embase, Cochrane, PubMed, Scopus, and Web of Science (WOS) databases to seek information and PRISMA system to delimitate the research. Outcomes included in searches were physical activity, tobacco consumption, obesity, body mass index, and metabolic syndrome, associated with bladder cancer and quality of life. RESULTS: Database searches identified 394 records, of which 75 were duplicated. A total of 280 articles were excluded based on abstract screening. An additional 16 full-text articles were excluded because they did not meet the eligibility criteria. Overall, 21 of the 23 studies included in the review reported beneficial effects of physical activity in bladder cancer. The majority of papers found that physical activity is a significant factor in reducing the risk of bladder cancer. Moreover, physical activity improves health-related quality of life in bladder cancer survivors, and diminishes both recurrence and mortality in those who engage in regular activity. Lastly, physical inactivity is associated with increased body mass index, obesity, metabolic syndrome, type 2 diabetes and unfavourable energy balance, which led to a greater probability of suffering from bladder cancer. CONCLUSIONS: These data reinforce the importance of promoting a healthy lifestyle to reduce the risk of bladder cancer and to improve survivorship and health-related quality of life of patients.

Association between physical activity, grip strength and sedentary behaviour with incidence of malignant melanoma: results from the UK Biobank

BACKGROUND

Physical activity has been positively related to malignant melanoma. However, that association may be confounded by ultraviolet radiation (UV), a variable closely related to both outdoor physical activity and malignant melanoma. We examined physical activity, grip strength and sedentary behaviour in relation to risk of malignant melanoma, accounting for relevant confounders using data from a prospective cohort study.

METHODS

In 350,512 UK Biobank participants aged 38-73 years at baseline, physical activity was assessed with a modified version of the International Physical Activity Questionnaire Short Form, grip strength was measured with a hand dynamometer, and sedentary behaviour was recorded with three specific questions. Multivariable hazard ratios (HR) and corresponding 95% confidence intervals (CI) were estimated using Cox proportional hazards regression.

RESULTS

During 7 years of follow-up, 1239 incident malignant melanoma diagnoses were recorded. Physical activity and sedentary behaviour were unrelated to malignant melanoma (HRs 1.01 (95% CI 0.95-1.07) and 1.04 (95% CI 0.97-1.12), respectively), and the initially positive association with grip strength in the basic model (HR 1.23, 95% CI 1.08-1.40) was attenuated after full adjustment (HR 1.10, 95% CI 0.96-1.26).

CONCLUSION

Physical activity, grip strength and sedentary behaviour are not associated with malignant melanoma risk.

Cardiorespiratory fitness is not associated with reduced risk of prostate cancer: A cohort study and review of the literature

BACKGROUND

Cardiorespiratory fitness (CRF) has a strong inverse relationship with several chronic disease outcomes, including some cancers. The association between CRF and prostate cancer is controversial. We aimed to assess the prospective association of CRF with prostate cancer risk using a cohort study and review of the literature.

MATERIAL AND METHODS

Cardiorespiratory fitness was assessed using a respiratory gas exchange analyser during exercise testing in 2204 cancer-free middle-aged men. Hazard ratios (HRs) with 95% confidence interval (CIs) were estimated. We corrected for within-person variability in CRF levels using repeat measurements.

RESULTS

During a median follow-up of 24.9 years, 216 prostate cancer cases occurred. The age-adjusted regression dilution ratio of CRF was 0.58 (95% CI: 0.53-0.64). The HR (95% CI) of prostate cancer per 1 standard deviation increase in CRF in age-adjusted analysis was 1.10 (0.95-1.27). The association remained consistent after further adjustment for several risk factors (HR 1.13; 95% CI 0.96-1.33). The corresponding adjusted HRs were 1.24 (95% CI: 0.87-1.77) and 1.28 (95% CI: 0.87-1.88), respectively, when comparing the extreme tertiles of CRF levels. Previous studies mostly reported no evidence of an association or an increased risk of prostate cancer in relation to high CRF. Studies reporting positive associations had short-term follow-up durations (<10 years).

CONCLUSIONS

Primary data and a review of previous studies suggest that elevated CRF is not associated with reduced prostate cancer risk. Previous findings of significant evidence of associations could be attributed to increased screening and detection as well as reverse causation bias.

Fitness and prostate cancer screening, incidence, and mortality: Results from the Henry Ford Exercise Testing (FIT) Project

BACKGROUND

The relation between cardiorespiratory fitness (CRF) and prostate cancer is not well established. The objective of this study was to determine whether CRF is associated with prostate cancer screening, incidence, or mortality.

METHODS

The Henry Ford Exercise Testing Project is a retrospective cohort study of men aged 40 to 70 years without cancer who underwent physician-referred exercise stress testing from 1995 to 2009. CRF was quantified in metabolic equivalents of task (METs) (<6 [reference], 6-9, 10-11, and ≥12 METs), estimated from the peak workload achieved during a symptom-limited, maximal exercise stress test. Prostate-specific antigen (PSA) testing, incident prostate cancer, and all-cause mortality were analyzed with multivariable adjusted Poisson regression and Cox proportional hazard models.

RESULTS

In total, 22,827 men were included, of whom 739 developed prostate cancer, with a median follow-up of 7.5 years. Men who had high fitness (≥12 METs) had an 28% higher risk of PSA screening (95% CI, 1.2-1.3) compared with those who had low fitness (<6 METs. After adjusting for PSA screening, fitness was associated with higher prostate cancer incidence (men aged <55 years, P = .02; men aged >55 years, P ≤ .01), but not with advanced prostate cancer. Among the men who were diagnosed with prostate cancer, high fitness was associated with a 60% lower risk of all-cause mortality (95% CI, 0.2-0.9).

CONCLUSIONS

Although men with high fitness are more likely to undergo PSA screening, this does not fully account for the increased incidence of prostate cancer seen among these individuals. However, men with high fitness have a lower risk of death after a prostate cancer diagnosis, suggesting that the cancers identified may be low-risk with little impact on long-term outcomes.

Normative reference values for estimated cardiorespiratory fitness in apparently healthy British men and women

Objectives

To develop normative reference standards for estimated cardiorespiratory fitness (eCRF) measured from treadmill-based incremental exercise testing in ~12 000 British men and women.

Methods

Cross-sectional study using retrospectively collected eCRF data from five preventative health screening clinics in the United Kingdom. Reference centiles were developed using a parametric approach by fitting fractional polynomials. We selected the ‘best’ powers by considering both the smallest deviance, and clinical knowledge from the following set of a priori decided powers (-2,-1,-0.5, 0, 0.5,1,2,3). A series of fractional polynomials (FPs) were investigated with three-parameters (median, standard deviation and skewness). The following reference centiles were plotted (3, 5, 10, 25, 50, 75, 90, 95, 97).

Results

We included 9 204 males (median [25^th,75^th centiles] age 48 [44, 53] years; BMI 27 {25, 29] kg∙m^-2; peak VO₂ 36.9 [30.5, 44.7] ml∙kg^-1∙min^-1) and 2 687 females (age 48, [41, 51] years; BMI 24 {22, 27] kg∙m^-2; peak VO₂ 36.5 [30.1, 44.8] ml∙kg^-1∙min^-1) in our analysis to develop the normative values.

Conclusion

Reference values and nomograms for eCRF were derived from a relatively large cohort of preventative health care screening examinations of apparently healthy British men and women. Age- and sex-specific eCRF percentiles were similar to data from international cohort studies. The adoption of submaximal exercise testing protocols reduces individual risk when exercise history is unknown and testing is conducted in a community-based setting. Our findings can be used by health professionals to help guide clinical decision making.

Early-Life Cardiorespiratory Fitness and Long-term Risk of Prostate Cancer

BACKGROUND

Adolescence is a period of rapid prostatic growth, yet is understudied for susceptibility for future risk of prostate cancer. We examined cardiorespiratory fitness (CRF) in late adolescence in relation to long-term prostate cancer risk.

METHODS

A population-based cohort study was conducted of all 699,125 Swedish military conscripts during 1972-1985 (97%-98% of 18-year-old men) in relation to risk of prostate cancer overall, aggressive prostate cancer, and prostate cancer mortality during 1998-2017 (ages 50-65 years). CRF was measured by maximal aerobic workload, and prostate cancer was ascertained using the National Prostate Cancer Register. Muscle strength was examined as a secondary predictor.

RESULTS

In 38.8 million person-years of follow-up, 10,782 (1.5%) men were diagnosed with prostate cancer. Adjusting for sociodemographic factors, height, weight, and family history of prostate cancer, high CRF was associated with a slightly increased risk of any prostate cancer [highest vs. lowest quintile: incidence rate ratio (IRR), 1.10; 95% CI, 1.03-1.19; P = 0.008], but was neither significantly associated with aggressive prostate cancer (1.01; 0.85-1.21; P = 0.90) nor prostate cancer mortality (1.24; 0.73-2.13; P = 0.42). High muscle strength also was associated with a modestly increased risk of any prostate cancer (highest vs. lowest quintile: IRR, 1.14; 95% CI, 1.07-1.23; P < 0.001), but neither with aggressive prostate cancer (0.88; 0.74-1.04; P = 0.14) nor prostate cancer mortality (0.81; 0.48-1.37; P = 0.43).

CONCLUSIONS

High CRF or muscle strength in late adolescence was associated with slightly increased future risk of prostate cancer, possibly related to increased screening, but neither with risk of aggressive prostate cancer nor prostate cancer mortality.

IMPACT

These findings illustrate the importance of distinguishing aggressive from indolent prostate cancer and assessing for potential detection bias.

Lifestyle associated factors and risk of urinary bladder cancer: A prospective cohort study from Norway

A number of lifestyle associated factors, such as high body mass index (BMI), low physical activity, and related metabolic disorders, are associated with increased risk of cancer at several sites. For urinary bladder cancer (BC), such studies show inconsistent results, which could result from inadequate adjustment for smoking and occupational exposure. In the population‐based Janus Cohort (n = 292 851), we investigated the independent and combined impact of BMI, physical activity, blood pressure, and blood lipids on the risk of BC, by thorough adjustment for smoking and potential occupational exposure. We used cox proportional hazard regression to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the associations between the lifestyle associated factors and BC risk. The associations observed were dependent on smoking status and gender. Among men, diastolic blood pressure (DBP) (HR 1.07, 95% CI 1.02‐1.12) and systolic blood pressure (SBP) (HR 1.04, 95% CI 1.01‐1.07) were positively associated with BC risk. Stratification by smoking status revealed a positive association between DBP and BC risk in never smokers (HR 1.14, 95% CI 1.00‐1.30), while no association was seen for current and former smokers. A risk score, integrating information across the lifestyle factors was positively associated with BC risk in men (p_trend = 0.043). In women, physical activity was associated with a decreased BC risk, but only among never smokers (HR 0.65, 95% CI 0.45‐0.94). In conclusion, relations between lifestyle associated factors and BC risk were most evident in never smokers, suggesting that smoking dominates the relation in current smokers.

Cardiorespiratory Fitness, Smoking Status, and Risk of Incidence and Mortality From Cancer: Findings From the Veterans Exercise Testing Study

BACKGROUND

To assess the joint and stratified associations between cardiorespiratory fitness (CRF), incidence, and mortality from cancer in never, former, and current male smokers.

METHODS

CRF (treadmill exercise test) was assessed in 4694 men (never smokers [n = 1715]; former smokers [n = 1602], 32.4 [30.5] pack-years; and current smokers [n = 1377], 40.3 [26] pack-years) aged 58.1 (17.3) years, and prospectively followed for 12.7 (7.5) years. Multivariable Cox hazard models were analyzed.

RESULTS

In joint analyses, where high CRF in never smokers was used as a reference, hazard ratios and 95% (confidence intervals) for cancer incidence and cancer mortality were as follows: moderate CRF 1.41 (1.0-1.9) and 3.0 (1.7-5.5) in never smokers, 1.65 (1.3-2.2) and 3.7 (2.1-6.6) in former smokers, and 1.3 (0.9-1.7) and 3.4 (1.9-6.1) in current smokers, respectively. The corresponding values for low CRF were 1.53 (1.1-2.2) and 5.1 (2.7-9.5), 1.84 (1.3-2.5) and 6.6 (3.7-11.8), and 1.5 (1.1-2.2) and 5 (2.7-9.3), respectively. In stratified analyses by smoking status, compared with low CRF, moderate and high CRF were associated with a 32% to 78% reduction in cancer mortality risk (P trend for all <.001).

CONCLUSION

Higher CRF is associated with lower risk of incidence and mortality from cancer regardless of smoking status, supporting the potential preventive benefits for public health.

Association between cardiorespiratory fitness and colorectal cancer in the UK Biobank

Increased cardiorespiratory fitness is related to decreased risk of major chronic illnesses, including cardiovascular disease, type 2 diabetes, and cancer, but its association with colorectal cancer specifically has received very little attention. We examined the relation of cardiorespiratory fitness to colorectal cancer in 59,191 UK Biobank participants aged 39-70 years without prevalent cancer at baseline, followed from 2009 to 2014. Submaximal bicycle ergometry was conducted at study entry, and cardiorespiratory fitness was defined as physical work capacity at 75% of the maximum heart rate, standardised to body mass (PWC_75%). Multivariable Cox proportional hazards regression was performed to obtain hazard ratios (HR) and corresponding 95% confidence intervals (CI). During a mean follow-up of 4.6 years, 232 participants developed colorectal cancer (151 colon cancers; 79 rectal cancers). When comparing the 75th to the 25th percentiles of PWC_75%, the multivariable-adjusted HR of colorectal cancer was 0.78 (95% CI 0.62-0.97). That relation was largely driven by an inverse association with colon cancer (HR 0.74, 95% CI 0.56-0.97) and less so with rectal cancer (HR 0.88, 95% CI 0.62-1.26; p value for difference by colorectal cancer endpoint = 0.056). The inverse relation of cardiorespiratory fitness with colorectal cancer was more evident in men (HR 0.72, 95% CI 0.55-0.94) than women (HR 0.99, 95% CI 0.71-1.38), although the gender difference was not statistically significant (p value for interaction = 0.192). Increased cardiorespiratory fitness is associated with decreased risk of colorectal cancer. Potential heterogeneity by colorectal cancer anatomic subsite and gender requires further study.

Cardiorespiratory Fitness, Lung Cancer Incidence, and Cancer Mortality in Male Smokers

INTRODUCTION

The preventive role of cardiorespiratory fitness in lung cancer among smokers is unknown. This study aims to evaluate the association between cardiorespiratory fitness and lung cancer incidence and cancer mortality in former and current male smokers.

METHODS

From 1987 to 2014, cardiorespiratory fitness (quantified from treadmill exercise testing) was assessed in 2,979 men (former smokers, n=1,602; current smokers, n=1,377) aged 59.1 (SD=17.4) years and prospectively followed up for 11.6 (SD=7) years. Multivariable Cox hazard models and population attributable fraction of low cardiorespiratory fitness (<5 METs) for cancer outcomes were analyzed during 2018.

RESULTS

Of the 99 case patients diagnosed with lung cancer, 79 died of cancer 3.6 (SD=4.6) years after diagnosis. Among former smokers, 1-MET increase and categories of moderate and high cardiorespiratory fitness were associated with 13% (p=0.016), 51%, and 77% (p-trend=0.015) reductions in lung cancer incidence, respectively. Among current smokers who were later diagnosed with lung cancer, 1-MET increase and categories of moderate and high cardiorespiratory fitness were associated with 18% (p=0.008), 84%, and 85% (p-trend<0.001) reductions in cancer mortality, respectively. The population attributable fraction for lung cancer incidence was 10.8% among former smokers and 22.3% for cancer mortality among current smokers.

CONCLUSIONS

Higher cardiorespiratory fitness is associated with lower risk of lung cancer incidence in former smokers and reduced risk of cancer mortality in current smokers who were diagnosed with lung cancer. Screening for low cardiorespiratory fitness and achieving at least moderate cardiorespiratory fitness could potentially reduce lung cancer morbidity and mortality, providing a preventive strategy for smokers.

Cardiorespiratory fitness and cancer in women: A prospective pilot study

PURPOSE

To assess the association between cardiorespiratory fitness (CRF) and the incidence and mortality from cancer in women, and to evaluate the potential public health implications for cancer prevention.

METHODS

Maximal exercise testing was performed in a pilot cohort of 184 women (59.3 ± 15.2 years) who were followed for 12.0 ± 6.9 years. Cox hazard models adjusted for established cancer risk factors and accounting for competing events were analyzed for all-type cancer incidence and mortality from cancer. Population-attributable risks and exposure impact number were determined for low CRF (<5 metabolic equivalents (METs)) as a risk factor.

RESULTS

During the follow-up, 11.4% of the participants were diagnosed with cancer and 3.2% died from cancer. CRF was inversely and independently associated with cancer outcomes. For every 1-metabolic equivalent increase in CRF, there was a 20% decrease in the risk of cancer incidence (hazard ratio (HR) = 0.80, 95% confidence interval (CI): 0.69-0.92; p = 0.001) and a 26% reduction in risk of cancer mortality (HR = 0.74, 95%CI: 0.61-0.90; p = 0.002). The population-attributable risks of low CRF were 11.6% and 14% for incidence and mortality of cancer, respectively, and the respective exposure impact numbers were 8 and 20.

CONCLUSION

Greater CRF was independently associated with a lower risk of incidence and mortality from cancer in women. Screening for low CRF as a cancer risk factor and referring unfit individuals to a supervised exercise program could be a public health strategy for cancer prevention in middle-age women.

The Influence of Change in Cardiorespiratory Fitness With Short-Term Exercise Training on Mortality Risk From The Ball State Adult Fitness Longitudinal Lifestyle Study

OBJECTIVE

To assess the influence of changes in cardiorespiratory fitness (CRF) after exercise training on mortality risk in a cohort of self-referred, apparently healthy adults.

PATIENTS AND METHODS

A total of 683 participants (404 men, 279 women; mean age: 42.7±11.0 y) underwent two maximal cardiopulmonary exercise tests (CPX) between March 20, 1970, and December 11, 2012, to assess CRF at baseline (CPX1) and post-exercise training (CPX2). Participants were followed for an average of 29.8±10.7 years after their CPX2. Cox proportional hazards models were performed to determine the relationship of CRF change with mortality, with change in CRF as a continuous variable, as well as a categorical variable. A Wald chi-square test was used to compare the coefficients estimating the relationship of peak oxygen consumption (VO_2peak) at CPX1 with VO_2peak measured at CPX2 with time until death for all-cause mortality.

RESULTS

During the follow-up period there were 180 deaths. When assessed independently, there were 20% (95% CI, 10-49%) and 38% (95% CI, 7-66%) lower mortality risks per 1 metabolic equivalent improvement in CRF (P<.01) in men and women, respectively, after multivariable adjustment. Those that remained unfit had ∼2-fold higher risk for all-cause mortality compared with those that remained fit and CRF at CPX2 was a stronger predictor of all-cause mortality than at CPX1 (P=.02).

CONCLUSION

Improving CRF through exercise training lowers mortality risk. Clinicians should encourage individuals to participate in exercise training to improve CRF to lower risk of mortality.

Cardiorespiratory fitness and incident lung and colorectal cancer in men and women: Results from the Henry Ford Exercise Testing (FIT) cohort

BACKGROUND

To the authors' knowledge, the relationship between cardiorespiratory fitness (CRF) and lung and colorectal cancer outcomes is not well established.

METHODS

A retrospective cohort study was performed of 49,143 consecutive patients who underwent clinician-referred exercise stress testing from 1991 through 2009. The patients ranged in age from 40 to 70 years, were without cancer, and were treated within the Henry Ford Health System in Detroit, Michigan. CRF, measured in metabolic equivalents of task (METs), was categorized as <6 (reference), 6 to 9, 10 to 11, and ≥12. Incident cancer was obtained through linkage to the cancer registry and all-cause mortality from the National Death Index.

RESULTS

Participants had a mean age of 54 ± 8 years. Approximately 46% were female, 64% were white, 29% were black, and 1% were Hispanic. The median follow-up was 7.7 years. Cox proportional hazard models, adjusted for age, race, sex, body mass index, smoking history, and diabetes, found that those in the highest fitness category (METs ≥12) had a 77% decreased risk of lung cancer (hazard ratio [HR], 0.23; 95% CI, 0.14-0.36) and a 61% decreased risk of incident colorectal cancer (HR, 0.39; 95% CI, 0.23-0.66; with additional adjustment for aspirin and statin use). Among those diagnosed with lung and colorectal cancer, those with high fitness had a decreased risk of subsequent death of 44% and 89%, respectively (HR, 0.56 [95% CI, 0.32-1.00] and HR, 0.11 [95% CI, 0.03-0.37], respectively).

CONCLUSIONS

In what to the authors' knowledge is the largest study performed to date, higher CRF was associated with a lower risk of incident lung and colorectal cancer in men and women and a lower risk of all-cause mortality among those diagnosed with lung or colorectal cancer.

Cardiorespiratory fitness and site-specific risk of cancer in men: A systematic review and meta-analysis

BACKGROUND

Cardiorespiratory fitness is a strong predictor of all-cause morbidity and mortality; nevertheless, the association between cardiorespiratory fitness and the risk of cancer remains unclear. Thus, the aim of this study was to synthetize the evidence on the relationship between cardiorespiratory fitness and the risk of several sites of cancer in men.

METHODS

A computerised search in MEDLINE, EMBASE and Web of Science databases from their inception to 13th February 2019 was performed. Both fixed and random-effects models were used to calculate the pooled hazard ratio (HR) estimates and their 95% confidence intervals (CIs) to examine the effect of high and moderate versus low cardiorespiratory fitness on site-specific cancer (lung, colon/rectum, prostate) and all-sites cancer.

RESULTS

Ten studies were included in the qualitative review, and seven of them were included in the meta-analysis. Using low cardiorespiratory fitness as the reference group, moderate and high levels of cardiorespiratory fitness were associated with a lower risk (HRs) of lung cancer, 0.53 (95% confidence interval [CI], 0.39 to 0.68) and 0.52 (95% CI, 0.42 to 0.61); colorectal cancer, 0.74 (95% CI, 0.55 to 0.93) and 0.77 (95% CI, 0.62 to 0.92) and all cancer sites, 0.86 (95% CI, 0.79 to 0.93) and 0.81 (95% CI, 0.75 to 0.87), respectively.

CONCLUSIONS

Among men, cardiorespiratory fitness plays an important role in protecting against the risk of lung and colorectal cancer. Additionally, this protective effect was observed for all-sites cancer risk. These results show the importance of good cardiorespiratory fitness as a potential factor in cancer prevention.

Aerobic fitness in late adolescence and the risk of cancer and cancer-associated mortality in adulthood: A prospective nationwide study of 1.2 million Swedish men

BACKGROUND

The incidence of cancer has steadily risen. It is important to identify modifiable predictors in early life that may decrease cancer risks and mortality. The present study aims to investigate the relationship between aerobic fitness in adolescence and the subsequent risk of cancer and cancer-associated mortality.

METHODS

The study included 1 185 439 Swedish men born between 1950 and 1980 that participated in the military conscription (mean age = 18 years). The results from the aerobic fitness test (W_max) was linked to the risk of cancer and cancer-associated mortality during a 40-years' follow-up using Cox proportional hazards models. A co-sibling design was employed to take familial factors into account.

RESULTS

During a mean follow-up of 27 years 15 093 cases of cancer and 4900 cancer-associated mortalities were registered. Higher W_max (per additional 1 SD) was associated with a decreased risk of cancer at 40 years of follow-up (HR 0.93; 95% CI 0.91-0.96 for cancer and HR 0.82 95% CI 0.76-0.87 for cancer-associated mortality) but not at 5 years of follow-up (HR 1.03; 95% CI 0.99-1.07; and HR 1.04; 95% CI 0.97-1.12). In the co-sibling model the protective effects of high W_max were increased at 40 years of follow-up for cancer (HR 0.91; 95% CI 0.85-0.98) and cancer-associated mortality (HR 0.78; 95% CI 0.68-0.89).

CONCLUSIONS

These findings identify in late adolescence a potentially modifiable predictor of cancer, with higher aerobic fitness associated with a decreased risk of cancer incidence and mortality later in life.

Physical activity, cardiorespiratory fitness and risk of cutaneous malignant melanoma: Systematic review and meta-analysis

BACKGROUND

Numerous epidemiologic studies have examined the relation of physical activity or cardiorespiratory fitness to risk of cutaneous melanoma but the available evidence has not yet been quantified in a systematic review and meta-analysis.

METHODS

Following the preferred reporting items for systematic reviews and meta-analyses (PRISMA), we identified 3 cohort studies (N = 12,605 cases) and 5 case-control studies (N = 1,295 cases) of physical activity and melanoma incidence, and one cohort study (N = 49 cases) of cardiorespiratory fitness and melanoma risk.

RESULTS

Cohort studies revealed a statistically significant positive association between high versus low physical activity and melanoma risk (RR = 1.27, 95% CI = 1.16-1.40). In contrast, case-control studies yielded a statistically non-significant inverse risk estimate for physical activity and melanoma (RR = 0.85, 95% CI = 0.63-1.14; P-difference = 0.02). The only available cohort study of cardiorespiratory fitness and melanoma risk reported a positive but statistically not significant association between the two (RR = 2.19, 95% CI = 0.99-4.96). Potential confounding by ultraviolet (UV) radiation-related risk factors was a major concern in cohort but not case-control studies.

CONCLUSIONS

It appears plausible that the positive relation of physical activity and cardiorespiratory fitness to melanoma observed in cohort studies is due to residual confounding by UV radiation-related risk factors.

IMPACT

Future prospective studies need to examine the association between physical activity, cardiorespiratory fitness and melanoma after detailed adjustment for UV radiation-related skin damage.

Cardiorespiratory fitness, incidence and mortality of lung cancer in men: A prospective cohort study

OBJECTIVES

To evaluate the association between cardiorespiratory fitness (CRF), lung cancer incidence and cancer mortality in men.

DESIGN

Prospective cohort study.

METHODS

Maximal exercise testing was performed in 4920 men (59.2±11.4years) free from malignancy at baseline. Multivariate Cox hazard models adjusted for established cancer risk factors including smoking were analyzed for lung cancer incidence and cancer mortality among those who were diagnosed with lung cancer. Population attributable risks (PAR) of low CRF (<5 METs) were determined.

RESULTS

During 12.7±7.5years follow-up, 105 (2.1%) participants were diagnosed with lung cancer and 83 (79%) of those died from cancer after 3.6±4.6 years from diagnosis. CRF was inversely and independently associated with cancer outcomes. A 1-MET increase and categories of moderate and high CRF were associated with 10%, 47% and 65% reduction in lung cancer incidence (p=0.002), and 13%, 58% and 76% reduction in cancer mortality (p=0.002), respectively. Also, individuals who were diagnosed with lung cancer and were at moderate or high CRF categories at baseline exhibited longer survival time (p<0.001). The PARs% for lung cancer incidence and cancer mortality were 8.7% and 18.5%, respectively.

CONCLUSIONS

Higher CRF is associated with lower lung cancer incidence in men. Among individuals who were diagnosed with lung cancer, higher CRF was associated with reduced cancer mortality and longer survival time. These results support the protective benefits of higher CRF in the prevention of lung cancer outcomes. Eliminating low CRF as a risk factor would potentially prevent considerable lung cancer morbidity and mortality.

Cardiorespiratory fitness and cancer incidence in men

PURPOSE

The preventive role of cardiorespiratory fitness (CRF) in cancer is not well established. The present study sought to evaluate the association between CRF and cancer incidence in men.

METHODS

Maximal exercise testing was performed in 4920 men (59.2 ± 11.4 years) free from malignancy at baseline who were followed for 12.7 ± 7.5 years. Relative risks and population attributable risks were determined.

RESULTS

During the follow-up, 25.8% were diagnosed with any type of cancer. CRF was inversely associated with total cancer incidence; for each one metabolic equivalent increase in CRF, there was a 4% reduction in cancer incidence (P < .001). Compared with low CRF, moderate and high CRF levels were associated with 14% (95% CI [0.74-0.99]) and 26% (95% CI [0.62-0.89]) reduced risks for all cancers, respectively (P for trend = .004). Low CRF had a population attributable risk of 3.0% for cancer incidence. The associations between CRF, prostate, skin and colorectal cancers were not significant.

CONCLUSIONS

Higher CRF is associated with lower total cancer incidence in men. A novel finding suggests that eliminating low CRF as a risk factor would potentially prevent considerable cancer morbidity and reduce the societal and economic burden associated with cancer. These findings underscore the importance of CRF for primary cancer prevention.

Cardiorespiratory fitness and risk of site-specific cancers: a long-term prospective cohort study

Based on self‐reported physical activity, there is epidemiologic evidence for a beneficial relation between physical activity and colon cancer in men, but findings for other cancers are inconclusive. Measured cardiorespiratory fitness (CRF) can provide knowledge about the cancer‐preventive value of physical activity. We aimed to assess relationships between CRF and risk of site‐specific cancers. A cohort of 1997 healthy Norwegian men, aged 40–59 years at inclusion in 1972–1975, was followed for cancer throughout 2012 using data from the Cancer Registry of Norway. CRF was measured by a maximal exercise bicycle test at inclusion. Relationships between CRF and site‐specific cancers were estimated using Cox regression, adjusted for age, body mass index, and smoking. During follow‐up, 898 cancer cases were diagnosed in 758 men. When comparing men in CRF tertile 1 with men in tertiles 2 and 3, respectively, we found decreased risk of proximal colon cancer in tertile 2 (HR: 0.30, 95% CI: 0.13–0.73) and decreased risk of cancers of lung (0.39 95% CI: 0.22–0.66), pancreas (0.32 95% CI: 0.10–1.00), and bladder (HR: 0.40 95% CI: 0.21–0.74) in tertile 3. Furthermore, a significant trend for lower risk by increasing CRF tertile was found for cancers of proximal colon, lung, and bladder (P‐value for trend <0.05). For other cancer sites, no significant association was found. Our results indicate that high midlife CRF may have cancer‐preventive value.