Cardiorespiratory fitness and digestive cancer mortality: findings from the aerobics center longitudinal study

The Association between Cardiorespiratory Fitness and the Risk of Breast Cancer in Women

INTRODUCTION

Studies have shown an inverse association between the risk of breast cancer in women and physical activity. However, information on the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized test and the risk of developing breast cancer is limited.

PURPOSE

To examine the CRF-breast cancer risk association in healthy females.

METHODS

This retrospective study was derived from the Exercise Testing and Health Outcomes Study cohort ( n = 750,302). Female participants ( n = 44,463; mean age ± SD; 55.1 ± 8.9 yr) who completed an exercise treadmill test evaluation (Bruce protocol) at the Veterans Affairs Medical Centers nationwide from 1999 to 2020 were studied. The cohort was stratified into four age-specific CRF categories (Least-fit, Low-fit, Moderate-fit, and Fit), based on the peak METs achieved during the exercise treadmill test.

RESULTS

During 438,613 person-years of observation, 994 women developed breast cancer. After controlling for covariates, the risk of breast cancer was inversely related to exercise capacity. For each 1-MET increase in CRF, the risk of cancer was 7% lower (HR, 0.93; 95% CI, 0.90-0.95; P < 0.001). When risk was assessed across CRF categories with the Least-fit group as the referent, the risk was 18% lower for Low-fit women (HR, 0.82; 95% CI, 0.70-0.96; P = 0.013), 31% for Moderate-fit (HR, 0.69; 95% CI, 0.58-0.82; P < 0.001), and 40% for Fit (HR, 0.60; 95% CI, 0.47-0.75; P < 0.001).

CONCLUSIONS

We observed an inverse and graded association between CRF and breast cancer risk in women. Thus, encouraging women to improve CRF may help attenuate the risk of developing breast cancer.

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.

Home-based prehabilitation improves physical conditions measured by ergospirometry and 6MWT in colorectal cancer patients: a randomized controlled pilot study

PURPOSE/BACKGROUND

Prehabilitation aims to improve physical condition in the preoperative period and, therefore, decrease the loss of cardiopulmonary capacity postoperatively, with the aim of reducing complications and promoting an early recovery. This study aims to evaluate the impact of home-based prehabilitation on the physical condition of patients treated surgically for colorectal cancer.

METHODS

A prospective and randomized clinical study was conducted on 60 patients during two periods from October 2018 to February 2019 and from September 2019 to September 2020, in a single university hospital. Patients were randomized into two study groups (30 per group): prehabilitation vs. standard care. Changes in physical condition, measured at diagnosis, the day before surgery, and at 6-8 weeks after surgery using the cardiopulmonary exercise testing (CPET) and the 6-minute walk test (6MWT) were evaluated.

RESULTS

Prehabilitation reduced postoperative complications (17.4% vs. 33.3%, p = 0.22) and hospital stay (5.74 vs. 6.67 days, p = 0.30). 6MWT showed a significant improvement in the prehabilitation group (+78.9 m). Six weeks after surgery, prehabilitation showed a significant improvement in the 6MWT (+68.9 m vs. -27.2 m, p = 0.01). Significant differences were also observed in the ergospirometry between the diagnosis and postoperative study (+0.79 METs vs. -0.84 METs, p = 0.001). A strong correlation was observed between CPET and 6MWT (0.767 (p < 0.001)).

CONCLUSION

Home prehabilitation achieved lower overall postoperative complications than standard care and reached significant improvements in 6MWT and CET. A strong correlation was observed between CET and 6MWT, which allows validation of 6MWT as a valid and reliable measure of functional exercise capacity in colorectal patients when other, more specific and expensive tests are not available.

TRIAL REGISTRATION

Registered in ClinicalTrials.gov in August 2018 with registration number https://clinicaltrials.gov/study/NCT03618329?cond=Prehabilitation%20cancer&term=arroyo&distance=50&rank=1  (NCT03618329). Initial results published in Supportive Care in Cancer: Effect of home-based prehabilitation in an enhanced recovery after surgery program for patients undergoing colorectal cancer surgery during the COVID-19 pandemic. DOI: https://doi.org/10.1007/s00520-021-06343-1 .

Associations between cardiorespiratory fitness and diverticulitis in older adults

Objectives

Examine the independent and joint associations of cardiorespiratory fitness (CRF) and body mass index (BMI) with the prevalence of diverticulitis in older adults.

Methods

476 older adults (61% Female; 71 ± 5 years) with no history of myocardial infarction, stroke, cancer, inflammatory bowel disease, or diabetes were included in this cross-sectional study. Diverticulitis cases were identified by self-reported physician diagnosis from the medical history questionnaire. Logistic regression was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of the prevalence of diverticulitis by tertiles of CRF and BMI category. CRF and BMI were further dichotomized into either “unfit” (the lowest one-third of CRF), “fit” (the upper two-thirds of CRF), “overweight/obese” (BMI ≥25.0 kg/m2), or “normal-weight” (BMI <25.0 kg/m2) to investigate the joint association of CRF and BMI with diverticulitis.

Results

Thirty-five (7.4%) participants were identified as having diverticulitis. Compared with the lowest CRF tertile, the ORs (95% CIs) of diverticulitis were 0.52 (0.22–1.22) and 0.33 (0.12–0.94) in the middle and upper CRF tertiles, respectively, after adjusting for potential confounders. After further adjustment for BMI, the association was no longer significant with ORs (95% CIs) of 0.55 (0.23–1.33) and 0.37 (0.12–1.10) in middle and upper CRF tertiles, respectively. Compared with the normal-weight group, the ORs (95% CIs) of diverticulitis were 2.86 (1.05–7.79) and 2.98 (0.95–9.35) in the overweight and obese groups, respectively, after adjusting for possible confounders and CRF. Compared with the “unfit and overweight/obese” group in the joint analysis, the OR (95% CI) of diverticulitis was 0.16 (0.04–0.61) in the “fit and normal-weight” group.

Conclusions

Older adults who maintain higher CRF and lower BMI may have significantly lower odds of diverticulitis, with the lowest odds found in the normal-weight and fit older adults.

Associations Between Muscular Strength and Gastroesophageal Reflux Disease in Older Adults

BACKGROUND

The association between muscular strength (MS) and prevalent gastroesophageal reflux disease (GERD) in the older adults is not well established.

METHODS

This study included 542 older adults with no history of myocardial infarction, stroke, or cancer. MS was measured by handgrip dynamometry. Participants were categorized into sex-specific quartiles of MS, while cases of GERD were identified by self-reported physician diagnosis. Logistic regression was used to calculate the odds ratios and 95% confidence intervals of GERD by quartiles of MS.

RESULTS

There were 112 GERD cases. Compared with the first quartile of MS, the odds ratios (95% confidence intervals) of GERD were 0.50 (0.27-0.95), 0.39 (0.20-0.75), and 0.55 (0.29-1.04) in the second, third, and fourth quartiles of MS, respectively, after adjusting for possible confounders including body mass index. In a joint analysis of MS and body mass index, participants were dichotomized into weak (first MS quartile) or strong (upper 3 MS quartiles) and normal weight, overweight, or obese. Compared with the weak-obese group, odds ratios (95% confidence intervals) were 0.34 (0.14-0.80), 0.43 (0.16-1.13), 0.29 (0.12-0.68), 0.18 (0.06-0.55), and 0.07 (0.03-0.21) for the strong-obese, weak-overweight, strong-overweight, weak-normal weight, and strong-normal weight.

CONCLUSIONS

MS was independently and inversely associated with GERD in older adults.

A randomized clinical trial to assess the effectiveness of pre- and post-surgical pelvic floor physiotherapy for bowel symptoms, pelvic floor function, and quality of life of patients with rectal cancer: CARRET protocol

Background

There is scarcity of trials about preventative strategies for low anterior resection syndrome (LARS) in rectal cancer patients. The aim of this study is to evaluate the effectiveness of a pre- and post-surgical pelvic floor rehabilitation program on the bowel symptoms, pelvic floor function, and quality of life of rectal cancer patients.

Methods

A randomized controlled trial with parallel groups (pelvic floor rehabilitation versus control group), with a blinded evaluator. Participants and setting: 56 stage I to III rectal cancer patients aged from 18 to 80 years old undergoing sphincter preservation surgery at Hospital del Salvador and who have a sufficient knowledge of Spanish. Main outcome measures: ICIQ-B questionnaire for intestinal symptoms, high-resolution anorectal manometry (Alacer Multiplex 24-channel manometry equipment) for anorectal function, pelvic floor muscle strength test with Oxford Modified Scale, and a quality of life test with the EORTC QLQ C30 questionnaire. The evaluations will be carried out at five stages: before surgery, before and after the pelvic floor rehabilitation, and during a 3-month and 1-year follow-up. Interventions: one pre-rehabilitation session and 9 to 12 sessions of pelvic floor rehabilitation, including patient education, pelvic floor muscle exercises, pelvic floor electromyography biofeedback, and capacitive and sensory rectal training with a balloon probe. Rehabilitation will begin 3–5 weeks before the ileostomy is removed (four sessions) and around 3 weeks after stoma removal (5–8 sessions).

Discussion

We expect the program to improve the bowel symptoms, pelvic floor function, and quality of life of rectal cancer patients.

Trial registration

Australian New Zealand Clinical Trials Register ACTRN12620000040965. Registered on 21 January 2020.

Semiparametric regression of the illness-death model with interval censored disease incidence time: An application to the ACLS data

To investigate the effect of fitness on cardiovascular disease and all-cause mortality using the Aerobics Center Longitudinal Study, we develop a semiparametric illness-death model account for intermittent observations of the cardiovascular disease incidence time and the right censored data of all-cause mortality. The main challenge in estimation is to handle the intermittent observations (interval censoring) of cardiovascular disease incidence time and we develop a semiparametric estimation method based on the expectation-maximization algorithm for a Markov illness-death regression model. The variance of the parameters is estimated using profile likelihood methods. The proposed method is evaluated using extensive simulation studies and illustrated with an application to the Aerobics Center Longitudinal Study data.

Reaching beyond the 'worried well': pre-adoption characteristics of participants in 'Men on the Move', a community-based physical activity programme

BACKGROUND

Issues surrounding gender and men's health have become an increasing focus of public health globally. Unhealthy lifestyles and lower engagement in health promotion initiatives contributed to lower life expectancy and higher mortality rates among men. This study presents the pre-adoption characteristics of men who registered for 'Men on the Move'-a community-based physical activity (CBPA) programme, to ascertain whether the programme reached its intended target group, i.e. 'at-risk' adult men who did not meet physical activity (PA) guidelines and were likely to have multiple risk factors for cardiovascular disease (CVD).

METHODS

Multiple recruitment strategies were adopted to engage the target group and baseline data collection included a range of demographic, self-report and outcome measures.

RESULTS

The recruitment strategy succeeded in reaching the target group, with the majority (n = 927) presenting being previously inactive (89.0%), overweight/obese (89.7%) and having multiple CVD risk factors (53.1% ≥ 2 risk factors). However, the strategy was less successful in engaging 'hard-to-reach' groups, with the majority being middle-aged, white, married/cohabiting, educated and employed.

CONCLUSIONS

A gender-sensitized, partnership and community outreach recruitment strategy can maximize the reach and recruitment of an 'at-risk' cohort for CBPA initiatives, but more targeted approaches are needed to recruit marginalized groups of men.

Rehabilitation strategies following oesophagogastric and Hepatopancreaticobiliary cancer (ReStOre II): a protocol for a randomized controlled trial

BACKGROUND

Curative treatment for upper gastrointestinal (UGI) and hepatopancreaticobiliary (HPB) cancers, involves complex surgical resection often in combination with neoadjuvant/adjuvant chemo/chemoradiotherapy. With advancing survival rates, there is an emergent cohort of UGI and HPB cancer survivors with physical and nutritional deficits, resultant from both the cancer and its treatments. Therefore, rehabilitation to counteract these impairments is required to maximise health related quality of life (HRQOL) in survivorship. The initial feasibility of a multidisciplinary rehabilitation programme for UGI survivors was established in the Rehabilitation Strategies following Oesophago-gastric Cancer (ReStOre) feasibility study and pilot randomised controlled trial (RCT). ReStOre II will now further investigate the efficacy of that programme as it applies to a wider cohort of UGI and HPB cancer survivors, namely survivors of cancer of the oesophagus, stomach, pancreas, and liver.

METHODS

The ReStOre II RCT will compare a 12-week multidisciplinary rehabilitation programme of supervised and self-managed exercise, dietary counselling, and education to standard survivorship care in a cohort of UGI and HPB cancer survivors who are > 3-months post-oesophagectomy/ gastrectomy/ pancreaticoduodenectomy, or major liver resection. One hundred twenty participants (60 per study arm) will be recruited to establish a mean increase in the primary outcome (cardiorespiratory fitness) of 3.5 ml/min/kg with 90% power, 5% significance allowing for 20% drop out. Study outcomes of physical function, body composition, nutritional status, HRQOL, and fatigue will be measured at baseline (T0), post-intervention (T1), and 3-months follow-up (T2). At 1-year follow-up (T3), HRQOL alone will be measured. The impact of ReStOre II on well-being will be examined qualitatively with focus groups/interviews (T1, T2). Bio-samples will be collected from T0-T2 to establish a national UGI and HPB cancer survivorship biobank. The cost effectiveness of ReStOre II will also be analysed.

DISCUSSION

This RCT will investigate the efficacy of a 12-week multidisciplinary rehabilitation programme for survivors of UGI and HPB cancer compared to standard survivorship care. If effective, ReStOre II will provide an exemplar model of rehabilitation for UGI and HPB cancer survivors.

TRIAL REGISTRATION

The study is registered with ClinicalTrials.gov, registration number: NCT03958019, date registered: 21/05/2019.

Physical activity interventions for disease-related physical and mental health during and following treatment in people with non-advanced colorectal cancer

BACKGROUND

Colorectal cancer is the third most commonly diagnosed cancer worldwide. A diagnosis of colorectal cancer and subsequent treatment can adversely affect an individuals physical and mental health. Benefits of physical activity interventions in alleviating treatment side effects have been demonstrated in other cancer populations. Given that regular physical activity can decrease the risk of colorectal cancer, and cardiovascular fitness is a strong predictor of all-cause and cancer mortality risk, physical activity interventions may have a role to play in the colorectal cancer control continuum. Evidence of the efficacy of physical activity interventions in this population remains unclear.

OBJECTIVES

To assess the effectiveness and safety of physical activity interventions on the disease-related physical and mental health of individuals diagnosed with non-advanced colorectal cancer, staged as T1-4 N0-2 M0, treated surgically or with neoadjuvant or adjuvant therapy (i.e. chemotherapy, radiotherapy or chemoradiotherapy), or both.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 6), along with OVID MEDLINE, six other databases and four trial registries with no language or date restrictions. We screened reference lists of relevant publications and handsearched meeting abstracts and conference proceedings of relevant organisations for additional relevant studies. All searches were completed between 6 June and 14 June 2019.

SELECTION CRITERIA

We included randomised control trials (RCTs) and cluster-RCTs comparing physical activity interventions, to usual care or no physical activity intervention in adults with non-advanced colorectal cancer.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, performed the data extraction, assessed the risk of bias and rated the quality of the studies using GRADE criteria. We pooled data for meta-analyses by length of follow-up, reported as mean differences (MDs) or standardised mean differences (SMDs) using random-effects wherever possible, or the fixed-effect model, where appropriate. If a meta-analysis was not possible, we synthesised studies narratively.

MAIN RESULTS

We identified 16 RCTs, involving 992 participants; 524 were allocated to a physical activity intervention group and 468 to a usual care control group. The mean age of participants ranged between 51 and 69 years. Ten studies included participants who had finished active treatment, two studies included participants who were receiving active treatment, two studies included both those receiving and finished active treatment. It was unclear whether participants were receiving or finished treatment in two studies. Type, setting and duration of physical activity intervention varied between trials. Three studies opted for supervised interventions, five for home-based self-directed interventions and seven studies opted for a combination of supervised and self-directed programmes. One study did not report the intervention setting. The most common intervention duration was 12 weeks (7 studies). Type of physical activity included walking, cycling, resistance exercise, yoga and core stabilisation exercise. Most of the uncertainty in judging study bias came from a lack of clarity around allocation concealment and blinding of outcome assessors. Blinding of participants and personnel was not possible. The quality of the evidence ranged from very low to moderate overall. We did not pool physical function results at immediate-term follow-up due to considerable variation in results and inconsistency of direction of effect. We are uncertain whether physical activity interventions improve physical function compared with usual care. We found no evidence of effect of physical activity interventions compared to usual care on disease-related mental health (anxiety: SMD -0.11, 95% confidence interval (CI) -0.40 to 0.18; 4 studies, 198 participants; I2 = 0%; and depression: SMD -0.21, 95% CI -0.50 to 0.08; 4 studies, 198 participants; I2 = 0%; moderate-quality evidence) at short- or medium-term follow-up. Seven studies reported on adverse events. We did not pool adverse events due to inconsistency in reporting and measurement. We found no evidence of serious adverse events in the intervention or usual care groups. Minor adverse events, such as neck, back and muscle pain were most commonly reported. No studies reported on overall survival or recurrence-free survival and no studies assessed outcomes at long-term follow-up We found evidence of positive effects of physical activity interventions on the aerobic fitness component of physical fitness (SMD 0.82, 95% CI 0.34 to 1.29; 7 studies, 295; I2 = 68%; low-quality evidence), cancer-related fatigue (MD 2.16, 95% CI 0.18 to 4.15; 6 studies, 230 participants; I2 = 18%; low-quality evidence) and health-related quality of life (SMD 0.36, 95% CI 0.10 to 0.62; 6 studies, 230 participants; I2 = 0%; moderate-quality evidence) at immediate-term follow-up. These positive effects were also observed at short-term follow-up but not medium-term follow-up. Only three studies reported medium-term follow-up for cancer-related fatigue and health-related quality of life.

AUTHORS' CONCLUSIONS

The findings of this review should be interpreted with caution due to the low number of studies included and the quality of the evidence. We are uncertain whether physical activity interventions improve physical function. Physical activity interventions may have no effect on disease-related mental health. Physical activity interventions may be beneficial for aerobic fitness, cancer-related fatigue and health-related quality of life up to six months follow-up. Where reported, adverse events were generally minor. Adequately powered RCTs of high methodological quality with longer-term follow-up are required to assess the effect of physical activity interventions on the disease-related physical and mental health and on survival of people with non-advanced colorectal cancer. Adverse events should be adequately reported.

Physical Activity and the Risk of Liver Cancer: A Systematic Review and Meta-Analysis of Prospective Studies and a Bias Analysis

BACKGROUND

Physical inactivity is an established risk factor for several cancers of the digestive system and female reproductive organs, but the evidence for liver cancers is less conclusive.

METHODS

The aim of this study was to synthesize prospective observational studies on the association of physical activity and liver cancer risk by means of a systematic review and meta-analysis. We searched Medline, Embase, and Scopus from inception to January 2019 for prospective studies investigating the association of physical activity and liver cancer risk. We calculated mean hazard ratios (HRs) and 95% confidence intervals (CIs) using a random-effects model. We quantified the extent to which an unmeasured confounder or an unaccounted selection variable could shift the mean hazard ratio to the null.

RESULTS

Fourteen prospective studies, including 6,440 liver cancers, were included in the systematic review and meta-analysis. The mean hazard ratio for high compared with low physical activity was 0.75 (95% CI = 0.63 to 0.89; 95% prediction interval = 0.52 to 1.07; I² = 64.2%). We estimated that 67.6% (95% CI = 56.6% to 78.5%) of all true effect estimates would have a hazard ratio less than 0.8. Bias analysis suggested than an unobserved confounder would have to be associated with a 1.99-fold increase in the risk of physical activity or liver cancer to explain away the observed mean hazard ratio. An unaccounted for selection variable would have to be related to exposure and endpoint with a relative risk of 1.58 to explain away the mean hazard ratio.

CONCLUSIONS

Physical activity is inversely related to the risk of liver cancer. Further studies with objectively measured physical activity and quasi-experimental designs addressing confounding are needed.

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.

Dose-response associations of cardiorespiratory fitness with all-cause mortality and incidence and mortality of cancer and cardiovascular and respiratory diseases: the UK Biobank cohort study

OBJECTIVE

To investigate the association of cardiorespiratory fitness with all-cause mortality, and cardiovascular disease (CVD), respiratory disease, chronic obstructive pulmonary disease (COPD) and cancer mortality and incidence.

DESIGN

Prospective population-based study.

SETTING

UK Biobank.

PARTICIPANTS

Of the 5 02 628 (5.5% response rate) participants recruited by UK Biobank, we included 73 259 (14.6%) participants with available data in this analysis. Of these, 1374 participants died and 4210 developed circulatory diseases, 1293 respiratory diseases and 4281 cancer, over a median of 5.0 years (IQR 4.3-5.7) follow-up.

MAIN OUTCOME MEASURES

All-cause mortality and circulatory disease, respiratory disease, COPD and cancer (such as colorectal, lung, breast and prostate) mortality/incidence. Fitness was estimated using a submaximal cycle ergometer test.

RESULTS

The HR for all-cause mortality for each metabolic equivalent of task (MET) higher fitness was 0.96 (95% CI 0.93 to 0.98). Similar results were observed for incident circulatory disease (HR 0.96 [0.95 to 0.97]), respiratory disease (HR 0.96 [0.94 to 0.98]), COPD (HR 0.90 [0.86 to 0.95) and colorectal cancer (HR 0.96 [0.92 to 1.00]). Nonlinear analysis revealed that a high level of fitness (>10METs) was associated with a greater incidence of atrial fibrillation (HR 1.24 [1.07 to 1.44]) and prostate cancer (HR 1.16 [1.02 to 1.32]) compared with average fitness. All results were adjusted for sociodemographic, lifestyle and dietary factors, body composition, and morbidity at baseline and excluded events in the first 2 years of follow-up.

CONCLUSIONS

Higher cardiorespiratory fitness was associated with lower risk of premature mortality and incidence of CVD, respiratory disease and colorectal cancer.

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.

A 3-minute test of cardiorespiratory fitness for use in primary care clinics

BACKGROUND

Cardiorespiratory fitness (CRF) is the only major risk factor that is not routinely assessed in the clinical setting, for preventive medicine. A valid and practical CRF test is needed for use in the clinics. The objective of this study is to demonstrate the validity of a 3-minute squat test to assess CRF in primary care.

METHODS

A cross-sectional study in which the participants performed both the Ruffier squat test and the Balke maximal treadmill test. The study was conducted in a clinical setting from September 2016 to March 2017. We recruited a convenient sample of 40 adults between 18 and 64 years from the general U.S. population. Participants completed 30 squats in 45 seconds, paced by a metronome. Heart rate was measured at rest (P1), immediately after the test (P2), one minute after the test (P3). [Formula: see text] was measured using the Balke maximal treadmill fitness test.

RESULTS

Of the 40 participants, there were 18 men and 22 women. Mean age was 31.2 years (SD = 9.9). We found that the best [Formula: see text] predictors were HR features P1/height and (P2-P3)/age3. Our best-performing model using these two features predicted individuals' CRF levels with an adjusted R2 of 0.637, sensitivity of 0.79, and specificity of 0.56.

CONCLUSIONS

The study provided strong evidence for the validity of the squat test in the clinical setting. Further, the equation of our model along with [Formula: see text] normative tables provides an efficient and easy way to assess CRF in a primary care setting.

Nonexercise Estimated Cardiorespiratory Fitness and All-Cancer Mortality: the NHANES III Study

OBJECTIVE

To examine the relationship between estimated cardiorespiratory fitness (eCRF) using nonexercise equations and all-cancer mortality in a representative sample of the US population.

PARTICIPANTS AND METHODS

A total of 8506 study participants were derived from the Third National Health and Nutrition Examination Survey, conducted from October 18, 1988, to October 15, 1994. They were followed for all-cancer mortality. Participants' CRF was estimated from nonexercise models that were determined by age, body mass index, waist circumference, resting heart rate, physical activity status, and smoking status, and further grouped into quintiles. Hazard ratios (HRs) and 95% CIs were calculated from Cox proportional hazards models for the relationship between eCRF and all-cancer mortality.

RESULTS

During a mean of 19.5 years of follow-up, 455 cancer deaths (263 men and 192 women) were registered. After adjustment for race/ethnicity, age, educational level, current smoking, hypertension, diabetes mellitus, and hypercholesterolemia, each 1-metabolic equivalent increase in eCRF was associated with 30% (95% CI, 24%-35%) and 27% (95% CI, 18%-36%) risk reduction for all-cancer mortality in men and women, respectively. When eCRF was categorized into quintiles, HRs (95% CIs) were 0.47 (0.24-0.95), 0.81 (0.46-1.44), 0.49 (0.26-0.93), and 0.57 (0.31-1.06) across incremental quintiles in women (quintile 1 was the reference group). However, none of the HRs reached statistical significance in men.

CONCLUSION

The eCRF was inversely associated with all-cancer mortality in quintiles 2 and 4 in women. More research is needed to further understand the association between eCRF and all-cancer mortality in men.

Cardiorespiratory fitness and adiposity in breast cancer survivors: is meeting current physical activity recommendations really enough?

PURPOSE

Breast cancer (BC) survivors are becoming increasingly predisposed to cardiovascular disease (CVD) mortality. Low cardiorespiratory fitness and physical activity (PA) levels, as well as high values of adiposity indices, contribute to CVD risk. We evaluated adiposity, cardiorespiratory profile, and PA levels in two independent cohorts of BC survivors.

METHODS

Data were collected from two groups (99% women) from different areas of Madrid (Spain): group 1, n = 110, age 51.4 ± 9.7 years, median time from diagnosis 365 days (95% confidence interval [CI], 354-401), and group 2, n = 93, age 54.7 ± 8.9 years, 1714 days (95% CI, 1502-1938). We estimated peak oxygen uptake (VO_2peak) and measured body mass index (BMI), waist circumference (WC), waist-to-hip index, and accelerometry-determined PA.

RESULTS

Both groups had values of BMI in the overweight range (25.3 ± 4.3 and 27.1 ± 5.1 kg/m², p = 0.003). Estimated VO_2peak levels were lower in group 2 than in group 1 (28.1 ± 9.1 and 23.7 ± 8.8 ml/kg/min, p < 0.001), although levels in both groups were low. Yet, the majority of participants in both groups (81 and 88%, p = 0.234) met international PA recommendations (235 ± 196 and 351 ± 173 min/week of moderate-vigorous PA, p < 0.001). Both groups had very low levels of vigorous PA. These results were essentially independent of type of treatment (anthracycline/radiotherapy).

CONCLUSIONS

We found a poor cardiorespiratory profile in two independent BC cohorts that differed in median time from diagnosis (as well in socioeconomic status), supporting the notion that implementation of PA (possibly focusing on vigorous PA) and dietary intervention is urgently needed in this patient population.

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.

Recent advances in the link between physical activity, sedentary behavior, physical fitness, and colorectal cancer

Physical inactivity is a well-established risk factor for colorectal cancer (CRC). Recent studies have characterized physical activity (PA), sedentary behavior, and cardiorespiratory fitness as distinct, interrelated constructs that influence the risk of CRC and related outcomes. PA levels required to confer protection against CRC may be higher than previously thought. Sedentary behavior, defined as time spent sitting, increases CRC risk independent of PA and may require novel interventions distinct from those targeting PA. Finally, cardiorespiratory fitness is inversely associated with CRC risk and mortality and may provide a potential tool for risk stratification and intervention.

Association of Physical Activity by Type and Intensity With Digestive System Cancer Risk

IMPORTANCE

Accumulating evidence indicates that common carcinogenic pathways may underlie digestive system cancers. Physical activity may influence these pathways. Yet, to our knowledge, no previous study has evaluated the role of physical activity in overall digestive system cancer risk.

OBJECTIVE

To examine the association between physical activity and digestive system cancer risk, accounting for amount, type (aerobic vs resistance), and intensity of physical activity.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study followed 43 479 men from the Health Professionals Follow-up Study from 1986 to 2012. At enrollment, the eligible participants were 40 years or older, were free of cancer, and reported physical activity. Follow-up rates exceeded 90% in each 2-year cycle.

EXPOSURES

The amount of total physical activity expressed in metabolic equivalent of task (MET)-hours/week.

MAIN OUTCOMES AND MEASURES

Incident cancer of the digestive system encompassing the digestive tract (mouth, throat, esophagus, stomach, small intestine, and colorectum) and digestive accessory organs (pancreas, gallbladder, and liver).

RESULTS

Over 686 924 person-years, we documented 1370 incident digestive system cancers. Higher levels of physical activity were associated with lower digestive system cancer risk (hazard ratio [HR], 0.74 for ≥63.0 vs ≤8.9 MET-hours/week; 95% CI, 0.59-0.93; P value for trend = .003). The inverse association was more evident with digestive tract cancers (HR, 0.66 for ≥63.0 vs ≤8.9 MET-hours/week; 95% CI, 0.51-0.87) than with digestive accessary organ cancers. Aerobic exercise was particularly beneficial against digestive system cancers, with the optimal benefit observed at approximately 30 MET-hours/week (HR, 0.68; 95% CI, 0.56-0.83; P value for nonlinearity = .02). Moreover, as long as the same level of MET-hour score was achieved from aerobic exercise, the magnitude of risk reduction was similar regardless of intensity of aerobic exercise.

CONCLUSIONS AND RELEVANCE

Physical activity, as indicated by MET-hours/week, was inversely associated with the risk of digestive system cancers, particularly digestive tract cancers, in men. The optimal benefit was observed through aerobic exercise of any intensity at the equivalent of energy expenditure of approximately 10 hours/week of walking at average pace. Future studies are warranted to confirm our findings and to translate them into clinical and public health recommendation.

Importance of Assessing Cardiorespiratory Fitness in Clinical Practice: A Case for Fitness as a Clinical Vital Sign: A Scientific Statement From the American Heart Association

Mounting evidence has firmly established that low levels of cardiorespiratory fitness (CRF) are associated with a high risk of cardiovascular disease, all-cause mortality, and mortality rates attributable to various cancers. A growing body of epidemiological and clinical evidence demonstrates not only that CRF is a potentially stronger predictor of mortality than established risk factors such as smoking, hypertension, high cholesterol, and type 2 diabetes mellitus, but that the addition of CRF to traditional risk factors significantly improves the reclassification of risk for adverse outcomes. The purpose of this statement is to review current knowledge related to the association between CRF and health outcomes, increase awareness of the added value of CRF to improve risk prediction, and suggest future directions in research. Although the statement is not intended to be a comprehensive review, critical references that address important advances in the field are highlighted. The underlying premise of this statement is that the addition of CRF for risk classification presents health professionals with unique opportunities to improve patient management and to encourage lifestyle-based strategies designed to reduce cardiovascular risk. These opportunities must be realized to optimize the prevention and treatment of cardiovascular disease and hence meet the American Heart Association's 2020 goals.

Exercise as medicine - evidence for prescribing exercise as therapy in 26 different chronic diseases

This review provides the reader with the up-to-date evidence-based basis for prescribing exercise as medicine in the treatment of 26 different diseases: psychiatric diseases (depression, anxiety, stress, schizophrenia); neurological diseases (dementia, Parkinson's disease, multiple sclerosis); metabolic diseases (obesity, hyperlipidemia, metabolic syndrome, polycystic ovarian syndrome, type 2 diabetes, type 1 diabetes); cardiovascular diseases (hypertension, coronary heart disease, heart failure, cerebral apoplexy, and claudication intermittent); pulmonary diseases (chronic obstructive pulmonary disease, asthma, cystic fibrosis); musculo-skeletal disorders (osteoarthritis, osteoporosis, back pain, rheumatoid arthritis); and cancer. The effect of exercise therapy on disease pathogenesis and symptoms are given and the possible mechanisms of action are discussed. We have interpreted the scientific literature and for each disease, we provide the reader with our best advice regarding the optimal type and dose for prescription of exercise.

Physical Activity and the Biliary Tract in Health and Disease

BACKGROUND

Cholecystitis and gallstones affect a large segment of the population in developed nations, and a small proportion of affected individuals subsequently develop cancer of the gallbladder. However, little is known about the possible beneficial effects of physical activity.

OBJECTIVE

Accordingly, a systematic review examined the influence of both acute and chronic exercise on gallbladder motility, and relationships were examined between habitual physical activity, gallbladder disease, and gallbladder cancer.

METHODS

A search of Ovid/MEDLINE from 1996 to November 2014 yielded 67 articles relating to physical activity and gallbladder function or disease; 18 of these relevant to the objectives of the review were supplemented by 22 papers from personal files and other sources. Because of the limited volume of material, all were considered, although note was taken of the quality of activity measurement, care in excluding covariates, and experimental design (cross-sectional, case-control or randomized controlled trial).

RESULTS

The impact of physical activity upon gallbladder function remains unclear; acute activity could augment emptying by stimulating cholecystokinin release, and one of two training experiments found a small increase in gallbladder motility. The largest and most recent cross-sectional and case-control trials show a reduced risk of gallbladder disease in active individuals. A small number of randomized controlled trials in humans and one animal study generally support these trends, although the number of cases of gallstones are too few for statistical significance. Three studies of gallbladder cancer also show a non-significant trend to benefit from physical activity.

CONCLUSIONS

Although there remains a need for further research, regular physical activity seems likely to reduce the risk of both gallstones and gallbladder cancer. A substantial number of individuals must be persuaded to exercise in order to avoid one case of gallbladder disease, but the attempt appears warranted because of the other health benefits of regular physical activity.

Measured cardiorespiratory fitness and self-reported physical activity: associations with cancer risk and death in a long-term prospective cohort study

Physical activity is inversely associated with risk of some cancers. The relation with cancer‐specific death remains uncertain. Mainly, studies on relationships between physical activity and cancer are based on self‐reported physical activity (SPA). Hereby, we examined whether measured cardiorespiratory fitness (CRF) is associated with cancer risk, mortality, and case fatality. We also describe relationships between SPA and these outcomes, and between CRF and SPA. A cohort of 1997 healthy Norwegian men, aged 40–59 years at inclusion in 1972–75, was followed throughout 2012. At baseline, CRF was objectively measured. SPA (leisure time and occupational) was obtained through a questionnaire. Relationships between CRF or SPA, and the outcomes were estimated using Cox regression, adjusted for age, body mass index (BMI), and smoking. Pearson correlation coefficients evaluated agreements between CRF and SPA. During follow‐up, 758 men were diagnosed with cancer and 433 cancer deaths occurred. Analyses revealed lower cancer risk (Hazard ratio [HR] 0.85, 95% confidence intervals [CI]: 0.68–1.00), mortality (HR 0.68, 95% CI: 0.53–0.88), and case fatality (HR 0.74, 95% CI: 0.57–0.96), in men with high CRF compared to low CRF. Light leisure time SPA was associated with lower cancer risk (HR 0.70, 95% CI: 0.56–0.86) and mortality (HR 0.64 95% CI: 0.49–0.83), whereas strenuous occupational SPA was associated with higher risks (HR 1.42, 95% CI: 1.13–1.78 and HR 1.45, 95% CI: 1.09–1.93). Correlations between CRF and SPA were 0.351 (P < 0.001) and −0.106 (P < 0.001) for leisure time and occupational SPA, respectively. A high midlife CRF may be beneficial for cancer risk, cancer mortality, and case fatality.

Increasing physical activity and exercise in lung cancer: reviewing safety, benefits, and application

Lung cancer continues to be a difficult disease frequently diagnosed in late stages with a high mortality and symptom burden. In part because of frequent lung comorbidity, even lung cancer survivors often remain symptomatic and functionally limited. Though targeted therapy continues to increase treatment options for advanced-stage disease, symptom burden remains high with few therapeutic options. In the last several decades, exercise and physical activity have arisen as therapeutic options for obstructive lung disease and lung cancer. To date, exercise has been shown to reduce symptoms, increase exercise tolerance, improve quality of life, and potentially reduce length of stay and postoperative complications. Multiple small trials have been performed in perioperative non-small-cell lung cancer patients, although fewer studies are available for patients with advanced-stage disease. Despite the increased interest in this subject over the last few years, a validated exercise regimen has not been established for perioperative or advanced-stage disease. Clinicians underutilize exercise and pulmonary rehabilitation as a therapy, in part because of the lack of evidence-based consensus as to how and when to implement increasing physical activity. This review summarizes the existing evidence on exercise in lung cancer patients.

Physical inactivity and low fitness deserve more attention to alter cancer risk and prognosis

Sedentary lifestyle is associated with elevated cancer risk whereas regular physical activity (PA) and high cardiorespiratory fitness (CRF) have the opposite effect, with several biologic mechanisms mediating such associations. There is a need for lifestyle interventions aimed at increasing the PA levels and CRF of the general population and particularly cancer survivors. Furthermore, provocative data suggest a dose-dependent benefit of increasing levels of PA and/or CRF against cancer risk or mortality. Thus, current PA guidelines (≥150 min/wk of moderate-to-vigorous PA) may not be sufficiently rigorous for preventing cancer nor for extending cancer survivorship. Research targeting this issue is urgently needed. Promoting regular PA along with monitoring indicators of CRF and adiposity may provide powerful strategies to prevent cancer in populations, help patients with cancer more effectively deal with their disease and enhance secondary prevention programs in those who are affected by cancer.

Cardiorespiratory fitness, body mass index, and cancer mortality: a cohort study of Japanese men

Background

The aim of this study is to investigate the independent and joint effects of cardiorespiratory fitness (CRF) and body mass index (BMI) on cancer mortality in a low body mass index population.

Methods

We evaluated CRF and BMI in relation to cancer mortality in 8760 Japanese men. The median BMI was 22.6 kg/m² (IQR: 21.0-24.3). The mean follow-up period was more than 20 years. Hazard ratios and 95% CI were obtained using a Cox proportional hazards model while adjusting for several confounding factors.

Results

Using the 2nd tertile of BMI (21.6-23.6 kg/m²) as reference, hazard ratios and 95% CI for the lowest tertile of BMI (18.5-21.5) were 1.26 (0.87–1.81), and 0.92 (0.64–1.34) for the highest tertile (23.7-37.4). Using the lowest tertile of CRF as reference, hazard ratios and 95% CIs for 2nd and highest tertiles of CRF were 0.78 (0.55–1.10) and 0.59 (0.40–0.88). We further calculated hazard ratios according to groups of men cross-tabulated by tertiles of CRF and BMI. Among men in the second tertile of BMI, those belonging to the lowest CRF tertile had a 53% lower risk of cancer mortality compared to those in the lowest CRF tertile (hazard ratio: 0.47, 95% CI: 0.23-0.97). Among those in the highest BMI tertile, the corresponding hazard ratio was 0.54 (0.25-1.17).

Conclusion

These results suggest that high CRF is associated with lower cancer mortality in a Japanese population of men with low average BMI.

Objectively assessed physical activity levels in Spanish cancer survivors

PURPOSE/OBJECTIVES

To objectively assess physical activity (PA) levels in a cohort of Spanish cancer survivors.

DESIGN

Descriptive, cross-sectional.

SETTING

The Hospital Universitario de Fuenlabrada and two healthcare centers in Madrid, Spain.

SAMPLE

204 cancer survivors and 115 adults with no history of cancer.

METHODS

Participants wore a triaxial accelerometer for seven or more consecutive days to assess PA levels. Body mass index (BMI), indirect indicators of adiposity (waist circumference, waist-to-hip ratio), and cardiorespiratory fitness also were determined.

MAIN RESEARCH VARIABLES

Light, moderate, vigorous, and total PA (sum of the former).

FINDINGS

Most (94%) of the cancer survivors met international recommendations for moderate PA, but very few (3%) fulfilled those (75 minutes or more per week) for vigorous PA. Except for lower total (minute per day, p=0.048) and vigorous PA levels (p<0.001 for both minute per day and minute per week) recorded in the cancer survivors group, no between-group differences were detected (p>0.05). A high percentage of the survivors (33%) were obese (BMI greater than 30 kg/m2), and many also showed poor cardiorespiratory fitness (45% were below the 8 metabolic equivalent threshold).

CONCLUSIONS

Although cancer survivors overall met international PA recommendations for a healthy lifestyle, their BMI and cardiorespiratory profiles were not within the healthy range.

IMPLICATIONS FOR NURSING

Cancer survivors need to be informed about healthy lifestyle habits and should be regularly monitored.

Cardiorespiratory fitness as predictor of cancer mortality: a systematic review and meta-analysis

BACKGROUND

Epidemiologic studies have reported that cardiorespiratory fitness is inversely associated with mortality from cancer. However, the evidence relating cardiorespiratory fitness to cancer mortality has not yet been quantitatively summarized.

METHODS

Following the preferred reporting items for sytematic reviews and meta-analyses (PRISMA) checklist, we conducted a systematic review and meta-analysis of the association between cardiorespiratory fitness and total cancer mortality. Relevant studies were identified through a literature search in PubMed up to August 2013 and by screening reference lists of qualifying articles. Data extraction was carried out independently by both authors and summary risk estimates were obtained using random-effects models.

RESULTS

Six prospective studies with an overall number of 71 654 individuals and 2002 cases of total cancer mortality were included. The median follow-up time in the studies was 16.4 years. Cardiorespiratory fitness showed a strong, graded, inverse association with total cancer mortality. Using low cardiorespiratory fitness as the reference group, intermediate and high levels of cardiorespiratory fitness were related to statistically significant decreased summary relative risks (RRs) of total cancer mortality of 0.80 [95% confidence interval (CI) 0.67-0.97] and 0.55 (95% CI 0.47-0.65), respectively. Studies that adjusted for adiposity yielded similar results to those that did not adjust for adiposity.

CONCLUSION

Increased cardiorespiratory fitness represents a strong predictor of decreased total cancer mortality risk, independent of adiposity.

Exercise-induced lung cancer regression: mechanistic findings from a mouse model

BACKGROUND

It has been demonstrated that regular exercise improves the quality of life in patients undergoing treatment for lung cancer and has been associated with reductions in cancer-specific mortality in patients with colon and breast cancer. The direct effects of cardiovascular exercise on lung cancer tumor biology, however, remain unknown. The authors evaluated the effects of cardiovascular exercise in a mouse model of lung adenocarcinoma.

METHODS

Luciferase-tagged A549 lung adenocarcinoma cells were injected through the tail vein of nude male mice. Then, the mice underwent weekly bioluminescent imaging until lung tumors were clearly identified. After lung tumors were identified, the mice were randomized to daily wheel running versus no wheel running, and they were imaged weekly. After 4 weeks, all mice were killed, and the lung tumors were harvested. Western blot and immunohistochemical analyses were conducted on tumor tissues to identify potential differences in protein expression levels in exercising mice versus sedentary mice.

RESULTS

Lung tumors in exercising mice grew significantly more slowly relative to sedentary mice. There was no change in the development of metastatic lesions between the 2 groups. Protein analysis by Western blot or immunohistochemical analysis demonstrated increased p53 protein levels in exercising mice relative to sedentary mice as well as increased mediators of apoptosis, including Bax and active caspase 3, in tumor tissues. In both groups of mice, no normal tissue toxicity was observed in other organs.

CONCLUSIONS

Daily cardiovascular exercise appears to mitigate the growth of lung adenocarcinoma tumors, possibly by activation of the p53 tumor suppressor function and increased apoptosis.

Chronic weight dissatisfaction predicts type 2 diabetes risk: aerobic center longitudinal study

OBJECTIVE

Weight dissatisfaction, defined as discordance between actual and goal weight, may be associated with increased risk for several obesity-related comorbidities. The purpose of the study was to examine the association between weight dissatisfaction and risk of developing Type 2 diabetes.

METHOD

This longitudinal study used data from 9,584 adults enrolled in the Aerobics Center Longitudinal Study. Key variables included multiple measures of measured weight, self-reported goal weight, and incident diabetes. Weight dissatisfaction was defined as being above the median of measured weight minus goal weight. Cox proportional hazards regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for diabetes incidence by weight dissatisfaction.

RESULTS

HRs for time until diabetes diagnosis revealed that family history of diabetes (HR = 1.46, 95% CI [1.13, 1.90]), age (HR = 1.03, 95% CI [1.02, 1.04]), and weight dissatisfaction (HR = 1.83, 95% CI [1.50, 2.25]) at baseline were statistically significant predictors. Longitudinally, higher risk was observed in individuals who either stayed dissatisfied (HR = 2.98, 95% CI [1.98, 4.48]) or became dissatisfied (HR = 1.51, 95% CI [0.79, 2.89]), compared with those who stayed satisfied. After additional adjustment for BMI, the elevated HR for those who remained dissatisfied compared with those who remained satisfied persisted (HR = 2.85, 95% CI [1.89, 4.31]).

CONCLUSIONS

Weight dissatisfaction, regardless of BMI, represents a potentially important psychophysiological modifier of the relationships between BMI and risk of Type 2 diabetes, and warrants greater attention in future studies of chronic disease risk.

Cancer prevention among adults aged 45-64 years: setting the stage

As part of setting the stage for this supplement to the American Journal of Preventive Medicine, a life-course perspective is presented to assist in understanding the importance of cancer prevention for adults in midlife, a period roughly spanning 20 years between ages 45 and 64 years. Drawing on disciplinary perspectives from the social sciences and public health, several life-course themes are delineated in this article: how specific life transitions present unique opportunities for interventions to inform policy and practice that can improve population health outcomes; how interventions can be focused on those at particular life stages or on the entire life course; and how the onset and progression of chronic conditions such as cancer are dependent on a complex interplay of critical and sensitive periods, and trajectory and accumulation processes. A translational research framework is applied to help promote the movement of applied public health interventions for cancer prevention into practice. Also explored are differences that can affect people at midlife relative to other age cohorts. Specifically, cancer-related risks and care networks are examined, with examples of public health strategies that can be applied to cancer prevention and control. As a conclusion, select methodologic issues and next steps for advancing research and practice are identified.

Feasibility and efficacy of a 12-week supervised exercise intervention for colorectal cancer survivors

Exercise training improves health-related physical fitness and patient-reported outcomes in cancer survivors, but few interventions have targeted colorectal cancer (CRC) survivors. This investigation aimed to determine the feasibility and efficacy of a 12-week supervised exercise training program for CRC survivors. Feasibility was assessed by tracking participant recruitment, loss to follow-up, assessment completion rates, participant evaluation, and adherence to the intervention. Efficacy was determined by changes in health-related physical fitness. Over a 1-year period, 72 of 351 (21%) CRC survivors screened were eligible for the study and 29 of the 72 (40%) were enrolled. Two participants were lost to follow-up (7%) and the completion rate for all study assessments was ≥93%. Mean adherence to the exercise intervention was 91% (standard deviation = ±18%), with a median of 98%. Participants rated the intervention positively (all items ≥ 6.6/7) and burden of testing low (all tests ≤ 2.4/7). Compared with baseline, CRC survivors showed improvements in peak oxygen uptake (mean change (MC) = +0.24 L·min(-1), p < 0.001), upper (MC = +7.0 kg, p < 0.001) and lower (MC = +26.5 kg, p < 0.001) body strength, waist circumference (MC = -2.1 cm, p = 0.005), sum of skinfolds (MC = -7.9 mm, p = 0.006), and trunk forward flexion (MC = +2.5 cm, p = 0.019). Exercise training was found to be feasible and improved many aspects of health-related physical fitness in CRC survivors that may be associated with improved quality of life and survival in these individuals.

Cardiorespiratory fitness protects against stress-related symptoms of burnout and depression

OBJECTIVE

To examine how cardiorespiratory fitness and self-perceived stress are associated with burnout and depression. To determine if any relationship between stress and burnout/depression is mitigated among participants with high fitness levels.

METHODS

197 participants (51% men, mean age=39.2 years) took part in the study. The Åstrand bicycle test was used to assess cardorespiratory fitness. Burnout was measured with the Shirom-Melamed Burnout Questionnaire (SMBQ), depressive symptoms with the Hospital Anxiety and Depression Scale (HAD-D). A gender-matched stratified sample was used to ensure that participants with varying stress levels were equally represented.

RESULTS

Participants with moderate and high fitness reported fewer symptoms of burnout and depression than participants with low fitness. Individuals with high stress who also had moderate or high fitness levels reported lower scores on the SMBQ Tension subscale and the HAD-D than individuals with high stress, but low fitness levels.

CONCLUSION

Better cardiovascular fitness seems to be associated with decreased symptoms of burnout and a better capacity to cope with stress.

PRACTICAL IMPLICATIONS

Promoting and measuring cardiorespiratory fitness can motivate employees to adopt a more physically active lifestyle and thus strengthen their ability to cope with stress exposure and stress-related disorders.

Physical activity, tumor PTGS2 expression, and survival in patients with colorectal cancer

BACKGROUND

Higher levels of physical activity are associated with lower colorectal carcinoma incidence and mortality, perhaps through influencing energy balance, cellular prosta7 systemic inflammation. Although evidence suggests interactive effects of energetics, sedentary lifestyle, and tumor CTNNB1 (β-catenin) or CDKN1B (p27) status on colon cancer prognosis, interactive effects of physical activity and tumor PTGS2 (the official symbol for COX-2) status on clinical outcome remain unknown.

METHODS

Using molecular pathological epidemiology database of 605 stage I-III colon and rectal cancers in two prospective cohort studies (the Nurse's Health Study and the Health Professionals Follow-up Study), we examined patient survival according to postdiagnosis physical activity and tumor PTGS2 status (with 382 PTGS2-positive and 223 PTGS2-negative tumors by immunohistochemistry). Cox proportional hazards models were used to calculate colorectal cancer-specific mortality HR, adjusting for clinical and other tumor variables including microsatellite instability status.

RESULTS

Among PTGS2-positive cases, compared with the least active first quartile, the multivariate HRs (95% confidence interval) were 0.30 (0.14-0.62) for the second, 0.38 (0.20-0.71) for the third, and 0.18 (0.08-0.41) for the fourth quartile of physical activity level (Ptrend = 0.0002). In contrast, among PTGS2-negative cases, physical activity level was not significantly associated with survival (Ptrend = 0.84; Pinteraction = 0.024, between physical activity and tumor PTGS2 status).

CONCLUSIONS

Postdiagnosis physical activity is associated with better survival among patients with PTGS2-positive tumors but not among patients with PTGS2-negative tumors.

IMPACT

Immunohistochemical PTGS2 expression in colorectal carcinoma may serve as a predictive biomarker in pathology practice, which may predict stronger benefit from exercise.

The association between frequency of vigorous physical activity and hepatobiliary cancers in the NIH-AARP Diet and Health Study

Despite a potential preventive effect of physical activity on hepatobiliary cancer, little information is available on the relation between the two. We studied the association between frequency of vigorous physical activity and hepatobiliary cancer among 507,897 participants of the NIH-AARP Diet and Health Study, aged 50-71 years at baseline in 1995/1996. During 10 years of follow-up, 628 incident cases of liver cancer and 317 cases of extrahepatic biliary tract cancer were registered. Physical activity levels were assigned according to the frequency of engagement in 20 min or more of vigorous physical activity per week: never/rarely (lowest level), less than once per week, 1-2 times per week, 3-4 times per week, 5 or more times per week (highest level). Using Cox regression, multivariate-adjusted relative risks (RR) comparing the highest with the lowest level of physical activity revealed a statistically significant decreased risk for liver cancer (RR = 0.64, 95% confidence interval (CI) = 0.49-0.84, p-trend <0.001), particularly hepatocellular carcinoma (RR = 0.56, 95% CI = 0.41-0.78, p-trend <0.001), independent of body mass index. By comparison, multivariate analyses indicated that physical activity was not statistically significantly associated with extrahepatic bile duct cancer (RR = 0.86, 95% CI = 0.45-1.65), ampulla of Vater cancer (RR = 0.66, 95% CI = 0.29-1.48), or gallbladder cancer (RR = 0.63, 95% CI = 0.33-1.21). These results suggest a potential preventive effect of physical activity on liver cancer but not extrahepatic biliary tract cancer, independent of body mass index.

Adults with greater weight satisfaction report more positive health behaviors and have better health status regardless of BMI

BACKGROUND

Prior studies suggest that weight satisfaction may preclude changes in behavior that lead to healthier weight among individuals who are overweight or obese.

OBJECTIVE

To gain a better understanding of complex relationships between weight satisfaction, weight-related health behaviors, and health outcomes.

DESIGN

Cross-sectional analysis of data from the Aerobics Center Longitudinal Study (ACLS).

PARTICIPANTS

Large mixed-gender cohort of primarily white, middle-to-upper socioeconomic status (SES) adults with baseline examination between 1987 and 2002 (n = 19,003).

MAIN OUTCOME VARIABLES

Weight satisfaction, weight-related health behaviors, chronic health conditions, and clinical health indicators.

STATISTICAL ANALYSES PERFORMED

Chi-square test, t-tests, and linear and multivariate logistic regression.

RESULTS

Compared to men, women were more likely to be dieting (32% women; 18% men) and had higher weight dissatisfaction. Men and women with greater weight dissatisfaction reported more dieting, yo-yo dieting, and snacking and consuming fewer meals, being less active, and having to eat either more or less than desired to maintain weight regardless of weight status. Those who were overweight or obese and dissatisfied with their weight had the poorest health.

CONCLUSION

Greater satisfaction with one's weight was associated with positive health behaviors and health outcomes in both men and women and across weight status groups.

p53, aerobic metabolism, and cancer

p53 regulates the cell cycle and deoxyribonucleic acid (DNA) repair pathways as part of its unequivocally important function to maintain genomic stability. Intriguingly, recent studies show that p53 can also transactivate genes involved in coordinating the two major pathways of energy generation to promote aerobic metabolism, but how this serves to maintain genomic stability is less clear. In an attempt to understand the biology, this review presents human epidemiologic data on the inverse relationship between aerobic capacity and cancer incidence that appears to be mirrored by the impact of p53 on aerobic capacity in mouse models. The review summarizes mechanisms by which p53 regulates mitochondrial respiration and proposes how this might contribute to maintaining genomic stability. Although disparate in nature, the data taken together suggest that the promotion of aerobic metabolism by p53 serves as an important tumor suppressor activity and may provide insights for cancer prevention strategies in the future.

Change in physical activity and colon cancer incidence and mortality

BACKGROUND

Although data on the association of physical activity and colon cancer risk is convincing, little research has examined whether change in physical activity alters risk of cancer incidence and mortality.

METHODS

We examined the association of 10- and 15-year change in physical activity with risk of colon cancer incidence and mortality in the Cancer Prevention Study II. Endpoints were verified through medical record abstraction or registry or National Death Index linkage. Ten-year physical activity analysis included 1,863 incident and 826 fatal cases, whereas the longer-term exposure analysis included 1,386 incident and 602 fatal colon cancer cases. Age and multivariable-adjusted hazard ratios were estimated using Cox proportional hazards models.

RESULTS

Neither measure of physical activity change was associated with colon cancer incidence. Fifteen-year change was not associated with colon cancer mortality. However, consistently high physical activity over 10 years was associated with a decreased risk of colon cancer mortality as compared with those with consistently low activity. The association attenuated to borderline significance with adjustment for body mass index. Those consistently at or above sample median physical activity levels over 15 years had half the risk of colon cancer death as those consistently below the median.

CONCLUSIONS

Regular long-term physical activity was associated with a lower risk of colon cancer mortality.

IMPACT

This study suggests that long-term participation in physical activity provides the greatest reduction in risk of colon cancer death.

Wheel running, skeletal muscle aerobic capacity and 1-methyl-1-nitrosourea induced mammary carcinogenesis in the rat

Emerging evidence indicates that intrinsic differences and induced changes in aerobic capacity are probably to play a critical role in the development of chronic diseases like cancer. This study was initiated: (i) to determine how citrate synthase activity, which is routinely used as a marker of aerobic capacity and mitochondrial density in skeletal muscle, was affected by voluntary running on either a motorized activity wheel or a non-motorized free wheel and (ii) to investigate the association between aerobic capacity and the carcinogenic response induced in the mammary gland by intraperitoneal injection of 1-methyl-1-nitrosurea. Overall, wheel running reduced cancer incidence (96 versus 72%, P = 0.0006) and the number of cancers per animal (2.84 versus 1.78, P < 0.0001) and induced citrate synthase activity (276 versus 353 U/mg, P < 0.0001, sedentary control versus wheel running,respectively). Both motorized and free wheel running increased citrate synthase activity (373 +/- 24, 329 +/- 11 and 276 +/- 9 U/mg protein, P < 0.0001) and reduced the average number of cancers per rat (2.84, 1.96 and 1.63, P < 0.01), sedentary control, free wheel and motorized wheel, respectively. However, regression analyses failed to provide evidence of a significant association between citrate synthase activity and either cancer incidence or cancer multiplicity. Citrate synthase activity is a single measure in a complex pathway that determines aerobic capacity. The multifaceted nature of intrinsic and inducible aerobic capacity limits the usefulness of citrate synthase activity alone in elucidating the relationship between aerobic capacity and the carcinogenic response.

Physical activity and gastrointestinal cancer survivorship

Research examining physical activity in gastrointestinal cancer survivors is in its early stages and has focused primarily on colorectal cancer. Moreover, the majority of the research to date has been observational in nature, with very little interventional research. Though limited, the results of this research have been promising in nature, showing positive associations between physical activity and quality of life as well as disease outcomes, including improved disease-free and overall survival. The potential benefits of physical activity for gastrointestinal cancer survivors warrant further research on the underlying mechanisms of the relationship between physical activity and colorectal cancer disease outcomes, to determine if these associations extend to other gastrointestinal cancers, and to determine appropriate physical activity interventions to realize any potential supportive care benefits in various gastrointestinal cancer survivor groups.