Recreational physical activity and cancer risk in subsites of the colon (the Nord-Trøndelag Health Study)

Non-occupational physical activity and risk of cardiovascular disease, cancer and mortality outcomes: a dose-response meta-analysis of large prospective studies

OBJECTIVE

To estimate the dose-response associations between non-occupational physical activity and several chronic disease and mortality outcomes in the general adult population.

DESIGN

Systematic review and cohort-level dose-response meta-analysis.

DATA SOURCES

PubMed, Scopus, Web of Science and reference lists of published studies.

ELIGIBILITY CRITERIA

Prospective cohort studies with (1) general population samples >10 000 adults, (2) ≥3 physical activity categories, and (3) risk measures and CIs for all-cause mortality or incident total cardiovascular disease, coronary heart disease, stroke, heart failure, total cancer and site-specific cancers (head and neck, myeloid leukaemia, myeloma, gastric cardia, lung, liver, endometrium, colon, breast, bladder, rectum, oesophagus, prostate, kidney).

RESULTS

196 articles were included, covering 94 cohorts with >30 million participants. The evidence base was largest for all-cause mortality (50 separate results; 163 415 543 person-years, 811 616 events), and incidence of cardiovascular disease (37 results; 28 884 209 person-years, 74 757 events) and cancer (31 results; 35 500 867 person-years, 185 870 events). In general, higher activity levels were associated with lower risk of all outcomes. Differences in risk were greater between 0 and 8.75 marginal metabolic equivalent of task-hours per week (mMET-hours/week) (equivalent to the recommended 150 min/week of moderate-to-vigorous aerobic physical activity), with smaller marginal differences in risk above this level to 17.5 mMET-hours/week, beyond which additional differences were small and uncertain. Associations were stronger for all-cause (relative risk (RR) at 8.75 mMET-hours/week: 0.69, 95% CI 0.65 to 0.73) and cardiovascular disease (RR at 8.75 mMET-hours/week: 0.71, 95% CI 0.66 to 0.77) mortality than for cancer mortality (RR at 8.75 mMET-hours/week: 0.85, 95% CI 0.81 to 0.89). If all insufficiently active individuals had achieved 8.75 mMET-hours/week, 15.7% (95% CI 13.1 to 18.2) of all premature deaths would have been averted.

CONCLUSIONS

Inverse non-linear dose-response associations suggest substantial protection against a range of chronic disease outcomes from small increases in non-occupational physical activity in inactive adults. PROSPERO registration number CRD42018095481.

Beyond colonoscopy: Physical activity as a viable adjunct to prevent colorectal cancer

Colorectal cancer (CRC) is a common cancer with an increasing incidence worldwide. The implementation of a mass screening program has been proven effective in reducing the global burden of CRC, but its effectiveness is not ideal and some metabolic derangements and lifestyle factors were reported to be attributable for such a deficit. Implementing positive lifestyle intervention as primary prevention therefore becomes critical because colorectal carcinogenesis can be promoted by several lifestyle factors, such as a lack of physical activity. Herein, we review the current evidence on the association and possible mechanisms between physical activity and CRC carcinogenesis. In addition, since CRC prevention heavily relies on resection of precancerous polyps and subsequent surveillance by colonoscopy, this review will also explore the impact of physical activity on populations with different colorectal polyp risks and its potential adjunct role in altering surveillance outcomes.

Pain and fatigue in adults with Loeys-Dietz syndrome and vascular Ehlers-Danlos syndrome, a questionnaire-based study

The purpose was to study self-reported chronic pain and fatigue symptoms among adults with molecularly verified Loeys-Dietz and vascular Ehlers-Danlos syndrome using a cross-sectional questionnaire design. Seventy adults were invited through a National Resource Centre for Rare Disorders. A study specific questionnaire including Brief Pain Inventory, Standardized Nordic Questionnaire, Fatigue Severity Scale, Hospital Anxiety & Depression Scale, questions on physical activity, and disease burden was used. Fifty-two persons participated, n = 34 with Loeys-Dietz and n = 18 with vascular Ehlers-Danlos syndrome, aged 18-68 years, 58% women. Chronic pain (79%) and fatigue (58%) symptoms were common. Half developed pain during childhood/adolescence. Sleep problems and high multi-organ burden were significantly associated with chronic pain (p = 0.004, p = 0.014) and high fatigue (p < 0.001, p < 0.001). Chronic pain was associated with higher scores of fatigue (p = 0.002). Higher scores of fatigue were associated with lower level of physical activity (p = 0.014), higher cardiovascular burden (p = 0.025), and higher symptoms of anxiety (p = 0.001). In this study, symptoms of chronic pain, fatigue, sleep problems, and disease burden seemed to mutually reinforce each other. Initiatives should consider interventions aimed at postponing the onset and reducing symptoms of pain, fatigue, and sleep problems and thus reduce the total disease burden at an early stage in patients with these complex conditions.

Association between physical activity and digestive-system cancer: An updated systematic review and meta-analysis

BACKGROUND

Physical activity (PA) may have an impact on digestive-system cancer (DSC) by improving insulin sensitivity and anticancer immune function and by reducing the exposure of the digestive tract to carcinogens by stimulating gastrointestinal motility, thus reducing transit time. The current study aimed to determine the effect of PA on different types of DSC via a systematic review and meta-analysis.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched for relevant studies in PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure. Using a random effects model, the relationship between PA and different types of DSC was analyzed.

RESULTS

The data used for meta-analysis were derived from 161 risk estimates in 47 studies involving 5,797,768 participants and 55,162 cases. We assessed the pooled associations between high vs. low PA levels and the risk of DSC (risk ratio (RR)  = 0.82, 95% confidence interval (95%CI): 0.79-0.85), colon cancer (RR = 0.81, 95%CI: 0.76-0.87), rectal cancer (RR = 0.88, 95%CI: 0.80-0.98), colorectal cancer (RR = 0.77, 95%CI: 0.69-0.85), gallbladder cancer (RR = 0.79, 95%CI: 0.64-0.98), gastric cancer (RR = 0.83, 95%CI: 0.76-0.91), liver cancer (RR = 0.73, 0.60-0.89), oropharyngeal cancer (RR = 0.79, 95%CI: 0.72-0.87), and pancreatic cancer (RR = 0.85, 95%CI: 0.78-0.93). The findings were comparable between case-control studies (RR = 0.73, 95%CI: 0.68-0.78) and prospective cohort studies (RR = 0.88, 95%CI: 0.80-0.91). The meta-analysis of 9 studies reporting low, moderate, and high PA levels, with 17 risk estimates, showed that compared to low PA, moderate PA may also reduce the risk of DSC (RR = 0.89, 95%CI: 0.80-1.00), while compared to moderate PA, high PA seemed to slightly increase the risk of DSC, although the results were not statistically significant (RR = 1.11, 95%CI: 0.94-1.32). In addition, limited evidence from 5 studies suggested that meeting the international PA guidelines might not significantly reduce the risk of DSC (RR = 0.96, 95%CI: 0.91-1.02).

CONCLUSION

Compared to previous research, this systematic review has provided more comprehensive information about the inverse relationship between PA and DSC risk. The updated evidence from the current meta-analysis indicates that a moderate-to-high PA level is a common protective factor that can significantly lower the overall risk of DSC. However, the reduction rate for specific cancers may vary. In addition, limited evidence suggests that meeting the international PA guidelines might not significantly reduce the risk of DSC. Thus, future studies must be conducted to determine the optimal dosage, frequency, intensity, and duration of PA required to reduce DSC risk effectively.

Adults with Loeys-Dietz syndrome and vascular Ehlers-Danlos syndrome: a cross-sectional study of patient experiences with physical activity

PURPOSE

To study patient experiences with physical activity among persons with Loeys-Dietz- or vascular Ehlers-Danlos syndrome.

MATERIALS AND METHODS

A postal questionnaire survey in 2018. Seventy adults with molecularly verified Loeys-Dietz syndrome types 1-4, or vascular Ehlers-Danlos syndrome recruited through a National Resource Centre for Rare Disorders in Norway.

RESULTS

The response rate was 74%, (Loeys-Dietz n = 34, vascular Ehlers-Danlos n = 18), aged 18 to 68 years, 58% women. In total, 88.5% reported they had received advice regarding physical activity and most (77%) had modified their habits. Fifty percent had an appropriate- and 40% a low mean physical activity sum score. Another 10% had too high physical activity levels due to high intensity scores. Lower scores with the Fatigue Severity Scale (p = 0.033) and the anxiety subscale of the Hospital Anxiety and Depression Scale (p = 0.021), were associated with high physical activity levels. About a third reported unmet rehabilitation needs.

CONCLUSION

Many adults with Loeys-Dietz- or vascular Ehlers-Danlos syndrome may have a potential to reach more favorable physical activity levels by increasing the frequency and duration of activities. Future directions should include evaluation of effects of professional-led practical and safe physical activity sessions as well as customized multidisciplinary rehabilitation programs for these patient groups.

A 5-Year Continued Follow-up of Cancer Risk and All-Cause Mortality Among Norwegian Military Peacekeepers Deployed to Kosovo During 1999-2016

INTRODUCTION

In 2012, Norwegian news media reported on cases of brain cancer among Norwegian peacekeeping troops who served in Kosovo, allegedly caused by exposure to depleted uranium fired during airstrikes before the peacekeepers arrived in 1999. A first study followed 6076 military men and women with peacekeeping service in Kosovo during 1999-2011 for cancers and deaths throughout 2011. The study did not support to the idea that peacekeeping service in Kosovo could lead to increased risk of brain cancer or other cancers. However, the average time of follow-up (10.6 years) was rather short for cancer development; therefore the aim of the present study was to evaluate cancer risk and general mortality in an updated cohort after 5 years of additional follow-up.

MATERIALS AND METHODS

The updated cohort consisted of 6,159 peacekeepers (5,884 men and 275 women) who served in Kosovo during 1999-2016 and were followed for cancer incidence and mortality from all causes combined throughout 2016. We calculated standardized incidence ratios (SIR) for cancer and standardized mortality ratios (SMR) from national population rates. Poisson regression was used to assess the effect of length of service (<1 year vs. ≥1 year) on cancer risk.

RESULTS

We observed 149 cancer cases and 75 deaths in the updated cohort. Observed cancer incidence did not exceed national rates. In men, the SIR for brain cancer was 0.73 (95% confidence interval (CI) 0.32-1.44), based on eight cases, while the risk of colon cancer was lowered (SIR = 0.14, 95% CI 0.00-0.79). The Poisson regression showed no effect of service duration on all-site cancer incidence. Mortality from all causes combined was lower than expected (SMR = 0.62, 95% CI 0.49-0.78) and in accordance with a "healthy soldier effect".

CONCLUSION

The extended follow-up did not give support to the suggestion that peacekeeping service in Kosovo could lead to increased risk of cancer.

Intestinal Microbiota: A Novel Target to Improve Anti-Tumor Treatment?

Recently, preclinical and clinical studies targeting several types of cancer strongly supported the key role of the gut microbiota in the modulation of host response to anti-tumoral therapies such as chemotherapy, immunotherapy, radiotherapy and even surgery. Intestinal microbiome has been shown to participate in the resistance to a wide range of anticancer treatments by direct interaction with the treatment or by indirectly stimulating host response through immunomodulation. Interestingly, these effects were described on colorectal cancer but also in other types of malignancies. In addition to their role in therapy efficacy, gut microbiota could also impact side effects induced by anticancer treatments. In the first part of this review, we summarized the role of the gut microbiome on the efficacy and side effects of various anticancer treatments and underlying mechanisms. In the second part, we described the new microbiota-targeting strategies, such as probiotics and prebiotics, antibiotics, fecal microbiota transplantation and physical activity, which could be effective adjuvant therapies developed in order to improve anticancer therapeutic efficiency.

Workplace Diesel Exhausts and Gasoline Exposure and Risk of Colorectal Cancer in Four Nordic Countries

BACKGROUND

Evidence on associations between occupational diesel exhaust and gasoline exposure and colorectal cancer is limited. We aimed to assess the effect of workplace exposure to diesel exhaust and gasoline on the risk of colorectal cancer.

METHODS

This case-control study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway, and Sweden. Cases and controls were identified from the Nordic Occupational Cancer Study cohort and matched for country, birth year, and sex. Diesel exhaust and gasoline exposure values were assigned by country-specific job-exposure matrices. Odds ratios and 95% confidence intervals were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work and occupational exposure to benzene, formaldehyde, ionizing radiation, chlorinated hydrocarbons, chromium, and wood dust.

RESULTS

Diesel exhaust exposure was associated with a small increase in the risk of rectal cancer (odds ratio = 1.05, 95% confidence interval 1.02-1.08). Gasoline exposure was not associated with colorectal cancer risk.

CONCLUSION

This study showed a small risk increase for rectal cancer after workplace diesel exhaust exposure. However, this finding could be due to chance, given the limitations of the study.

Physical Activity and Gastrointestinal Cancer Risk: A Review

Introduction: Western lifestyle characterized by increased consumption of red meat, fat, processed food, smoking, alcohol drinking, lower consumption of vegetables and physical inactivity has been associated with a higher gastrointestinal cancer risk. Digestive system cancers are diagnosed at late stages when they show poor response to treatment and are associated with a high mortality rate. Colorectal, gastric, esophageal and pancreatic cancers are among the most common cancers worldwide. Studies show that more than 50% of gastrointestinal cancers develop as a result of inappropriate lifestyle. An inverse association between physical activity and many chronic diseases has been proved so far. However, the association between physical activity and some gastrointestinal cancers is still controversial. This study was aimed to determine the association between physical activity and gastrointestinal cancers risk.

Methods: We conducted a comprehensive search of English and Persian databases from February 2007 till December 2017, for studies investigating the association of physical activity and risk of gastrointestinal cancers. Finally, after reading full text of articles, 123 studies were included.

Results: Physical activity can be helpful in reducing the risk of gastrointestinal cancer, especially colon and pancreatic cancers. The risk reduction is not similar for different types of gastrointestinal cancers and also among males and females.

Conclusion: Different types of physical activity are associated with a lower risk of gastrointestinal cancer. However, it is unknown which type and intensity of physical activity are associated with a protective effect against gastro-intestinal cancer.

Physical activity patterns and the risk of colorectal cancer in the Norwegian Women and Cancer study: a population-based prospective study

Introduction

Colorectal cancer (CRC) remains the second most common cancer in women worldwide. Physical activity (PA) has been associated with reduced risk of CRC; however, this has been demonstrated more consistently in men, while results of studies in women have been largely equivocal. We aimed to further examine the relationship between PA patterns and the risk of CRC in women, using repeated measurements.

Methods

We followed participants of the Norwegian Women and Cancer (NOWAC) Study - a nationally representative cohort. Baseline information was available for 79,184 women, and we used this information in addition to follow-up information collected 6–8 years later, for repeated measurement analysis. At enrollment, participants were cancer-free and aged 30–70 years, with a median age of 51 years. We used Cox proportional hazards regression to compute hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

During an average of 14.6 years of follow-up and 1.16 million person-years, 885 cases of colon and 426 cases of rectal cancer were identified through linkage to the Norwegian Cancer Registry (median age at diagnosis: 65 years). We found no association between PA level and the risk of colon cancer in baseline or repeated measurements analyses when comparing women with PA level 1–2 to those with PA level 5–6 (reference) (baseline: HR = 0.90, 95% CI 0.66–1.23, p-trend = 0.76; repeated measurements: HR = 0.78, 95% CI 0.55–1.10, p-trend = 0.27). Results were the same when comparing PA level 9–10 to the reference level (baseline: HR = 0.80, 95% CI 0.56–1.12, p-trend = 0.76; repeated measurements: HR = 0.82, 95% CI 0.58–1.16, p-trend = 0.27). Similarly, we found no association between PA levels and the risk of rectal cancer.

Conclusions

Women may need to look beyond PA in order to reduce their risk of CRC.

Domain-specific physical activity and sedentary behaviour in relation to colon and rectal cancer risk: a systematic review and meta-analysis

Background

Physical activity is associated with reduced risk of colorectal cancer, but most epidemiological studies have focused on occupational and recreational physical activity. The evidence for other domains of activity, and for sedentary behaviour, is limited.

Methods

Medline, Embase and Web of Science were searched from inception to December 2015 for studies examining domain-specific physical activity or sedentary behaviour and the risk of colon and/or rectal cancer. We extracted maximally adjusted relative risks (RRs) except when RRs not adjusted for body mass index, were also presented. We used random-effects meta-analysis to compute pooled RRs comparing the highest versus the lowest level of exposure. We used meta-regression to assess sources of heterogeneity in estimates.

Results

We identified 17 cohort and 21 case-control studies, of which 17 had occupational data, 23 had recreational data, three each had data on transport and household physical activity domains, and 6 studies had data on occupational sedentary behaviour. The pooled relative risks (RRs) for colon cancer were 0.74 (95% confidence interval (CI): 0.67, 0.82) for occupational activity, 0.80 (95% CI: 0.71, 0.89) for recreational activity, 0.66 (95% CI: 0.45, 0.98) for transport-related physical activity, 0.85 (95% CI: 0.71, 1.02) for household physical activity, and 1.44 (95% CI: 1.28, 1.62) for occupational sedentary behaviour. For rectal cancer, the pooled RRs were 0.88 (95% CI: 0.79, 0.98) for occupational activity, 0.87 (95% CI: 0.75, 1.01) for recreational activity, 0.88 (95% CI: 0.70, 1.12) for transport-related physical activity, 1.01 (95% CI: 0.80, 1.27) for household physical activity, and 1.02 (95% CI: 0.82, 1.28) for occupational sedentary behaviour.

Conclusions

In addition to increasing occupational and recreational physical activity, promoting physical activity during transport and reducing sedentary behaviour in the workplace may also be useful colorectal cancer prevention strategies.

Benzene exposure at workplace and risk of colorectal cancer in four Nordic countries

OBJECTIVE

The aim of this case-control study was to assess the effect of occupational benzene exposure on the risk of colorectal cancer, including its subtypes.

METHODS

The study included 181,709 colon cancer and 109,227 rectal cancer cases diagnosed between 1961 and 2005 in Finland, Iceland, Norway and Sweden. Cases were identified from the Nordic Occupational Cancer Study (NOCCA) cohort. Five controls per case were selected from the same cohort, matched for country, birth year, and sex. Occupational benzene exposure for each study participant was estimated by linking their job titles to country specific job-exposure matrices. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by using conditional logistic regression models. The results were adjusted for physical strain at work, formaldehyde, ionizing radiation and wood dust.

RESULTS

Increased risk was observed for all colorectal cancer (OR = 1.12, 95% CI 1.05-1.18) for the high decile of cumulative benzene exposure, indicating a statistically significant dose-response relationship. This excess risk was mainly seen in ascending colon (OR = 1.27, 95% CI 1.13-1.43), and transversal colon (OR = 1.21, 95% CI 1.01-1.41). The ORs in the highest exposure category were markedly higher in women than in men in all subsites of colon and rectum.

CONCLUSION

This study showed an association between workplace benzene exposure and colorectal cancer. The risk was restricted to ascending and transversal colon, and was the strongest among women.

Physical activity, obesity and sedentary behaviour and the risks of colon and rectal cancers in the 45 and up study

Background

Obesity and physical activity (PA) are predictors of colon (CC) and rectal (RC) cancers. Prolonged sitting is also emerging as a potential predictor for these cancers. Little knowledge exists about the interactive effects of obesity, PA and prolonged sitting on cancer risk. This analysis assessed independent and interactive effects of PA, body mass index (BMI) and sitting time on CC and RC risks.

Methods

This analysis used data from a prospective study of 226,584 participants aged 45 years and over in New South Wales (NSW), Australia, who joined the 45 and Up study between 2006 and 2009. Baseline data were linked with data relating to mortality, cancer registration, hospital admission and Department of Human Services to December 2010. Multivariable Cox regression was used to estimate adjusted hazard ratios (referred to as relative risks, RRs) and 95% confidence intervals (Cis). Statistical significance was defined as p < 0.05.

Results

There were 846 and 369 ascertained cases of CC and RC. BMI was positively associated with CC risk (p = 0.003, P-trend = 0.0006) but not with RC. CC risk was increased in participants in the highest BMI quartile (≥29.4-≤50 kg/m²) compared to the lowest (15- < 23.6 kg/m²), (RR = 1.32, 95% CI:1.08–1.63). PA was associated with CC risk (p = 0.02) but not with RC. Specifically, CC risk was lower in individuals partaking in any amount of vigorous activity (time/week) compared to participants with no engagement (RR = 0.78, 95% CI:0.65–0.93). Sitting time was not associated with CC or RC. We found no evidence of interactive effects of PA, BMI and prolonged sitting on cancer risk.

Conclusion

This evidence suggests that a healthy weight and vigorous activity are essential to reduce CC risk since these factors may be independent of each other.

Cardiorespiratory fitness in long-term lymphoma survivors after high-dose chemotherapy with autologous stem cell transplantation

Background:

Cardiorespiratory fitness as measured by peak oxygen consumption (VO_2peak) is a strong predictor of longevity and may be compromised by anticancer therapy, inactivity, and smoking. We compared VO_2peak among lymphoma survivors (LSs) with reference data from healthy sedentary subjects, after a 10.2-year (mean) follow-up post high-dose chemotherapy with autologous stem cell transplantation (HDT-ASCT). We further examined the association between VO_2peak and treatment, physical activity, smoking, pulmonary, and cardiac function.

Methods:

Lymphoma survivors treated with HDT-ASCT in Norway 1987–2008 were eligible. VO_2peak was assessed by cardiopulmonary exercise testing. Pulmonary function testing and echocardiography were also conducted. Data on treatment, physical activity, and smoking were collected from hospital records and questionnaires. VO_2peak was compared with age–sex predicted reference data. Linear regression was used to associate clinical factors with VO_2peak cross-sectionally.

Results:

A total of 194 LSs without heart failure were studied. Mean VO_2peak was 4.5% and 7.7% below norms in females and males, respectively. Twenty-two percent had impaired (<80% predicted) VO_2peak. Decreasing VO_2peak was associated with impaired diffusion capacity and current smoking, while physical activity level and VO_2peak were positively associated.

Conclusion:

We suggest increased attention towards physical activity counseling and smoking cessation advice to preserve cardiorespiratory fitness in LSs after HDT-ASCT. Patients with impaired diffusion capacity may benefit from subsequent monitoring to detect pulmonary vascular diseases.

Leisure time physical activity and cancer risk: evaluation of the WHO's recommendation based on 126 high-quality epidemiological studies

BACKGROUND

The WHO has concluded that physical activity reduces the risk of numerous diseases. However, few systemic reviews have been performed to assess the role of leisure time physical activity (LTPA) in lowering the risk of cancer in a dose-dependent manner and furthermore the suitability of recommendation of physical activity by the WHO.

METHODS

A systematic review and meta-analysis was designed to estimate cancer risk by LTPA in binary comparison and in a dose-dependent manner. MEDLINE and Web of Science were searched up to 30 December 2014 without language restrictions. Reference lists were reviewed for potential articles.

RESULTS

A total of 126 studies were recruited into the meta-analysis. Overall, the total cancer risk was reduced by 10% in people who undertook the most LTPA as compared with those who did the least. Dose-response meta-analysis indicated that the current WHO recommendation (equal to an average of 10 metabolic equivalents of energy hours per week) induced a 7% (95% CI 5% to 9%) cancer reduction. Moreover, the protective role of LTPA against cancer becomes saturated at 20 metabolic equivalents of energy hours per week, with a relative risk of 0.91 (95% CI 0.88 to 0.93). Subanalyses results based on cancer types showed that LTPA only exhibited significant protection against breast cancer and colorectal cancer.

CONCLUSIONS

Our meta-analysis indicates that the current WHO recommendation of physical activity can result in a 7% reduction in cancer risk, which is mainly attributed to its protective role against breast cancer and colorectal cancer. Furthermore, two-fold of current recommendation level is considered to give its saturated protection against cancer.

Addressing the needs of colorectal cancer survivors: current strategies and future directions

Colorectal cancer (CRC) is one of the three topmost common cancers in men and the second most common cancer in women worldwide. With current advances in the medical and surgical treatment of CRC, care has slowly transformed to curative treatment. With these advances, CRC survivors are increasing in numbers and these patients have a unique range of medical, physical and psychological needs that require regular follow-up. In 2006, the Institute of Medicine recommended that cancer survivors who are completing primary treatment receive a survivorship care plan. There are many different programs of different complexity that are implemented for CRC survivors. This review outlines the needs of CRC survivors, the current surveillance techniques used in the continuing care of patients with CRC after curative treatment and the evidence behind these strategies.

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 mTOR Pathway and the Role of Energy Balance Throughout Life in Colorectal Cancer Etiology and Prognosis: Unravelling Mechanisms Through a Multidimensional Molecular Epidemiologic Approach

Timing of exposure to lifestyle factors that influence energy balance may differentially affect colorectal cancer (CRC) risk and prognosis. Caloric restriction in youth and short stature, as markers of early-life exposures, have shown to decrease CRC risk, whereas large body size and low physical activity levels in adulthood are established risk factors for CRC. Regarding prognosis, overweight, sarcopenia, and their co-occurrence (sarcopenic obesity) may negatively influence the health and quality of life of CRC survivors. There is mechanistic support for disruption of the mammalian target of rapamycin (mTOR) pathway as an underlying mechanism possibly driving these associations, because mTOR integrates signals from growth factors, nutrients, mutagens, and hormones to induce cell proliferation, resistance to apoptosis, and autophagy. However, epidemiologic evidence connecting mTOR to energy-balance-related CRC throughout the lifespan is scarce. This perspective proposes how multidimensional molecular epidemiologic studies can shed light on the etiology and prognosis of energy-balance-related CRC.

Physical activity and risks of proximal and distal colon cancers: a systematic review and meta-analysis

BACKGROUND

Although there is convincing epidemiological evidence that physical activity is associated with a reduced risk of colon cancer, it is unclear whether physical activity is differentially associated with the risks of proximal colon and distal colon cancers. We conducted a systematic review and meta-analysis to investigate this issue.

METHODS

MEDLINE and EMBASE were searched for English-language cohort and case-control studies that examined associations between physical activity and the risks of proximal colon and distal colon cancers. A random-effects meta-analysis was conducted to estimate the summary relative risks (RRs) for the associations between physical activity and the risks of the two cancers. All statistical tests were two-sided.

RESULTS

A total of 21 studies met the inclusion criteria. The summary relative risk of the main results from these studies indicated that the risk of proximal colon cancer was 27% lower among the most physically active people compared with the least active people (RR = 0.73, 95% confidence interval [CI] = 0.66 to 0.81). An almost identical result was found for distal colon cancer (RR = 0.74, 95% CI = 0.68 to 0.80).

CONCLUSION

The results of this systematic review and meta-analysis suggest that physical activity is associated with a reduced risk of both proximal colon and distal colon cancers, and that the magnitude of the association does not differ by subsite. Given this finding, future research on physical activity and colon cancer should focus on other aspects of the association that remain unclear, such as whether sedentary behavior and nonaerobic physical activity are associated with the risk of colon cancer.

Physical activity reduces risk for colon polyps in a multiethnic colorectal cancer screening population

Background

Identifying modifiable factors that influence the epidemiology of colorectal cancer incidence among multiethnic groups might be informative for the development of public health strategies targeting the disease. Minimal data exists describing the impact of physical activity on colorectal polyp risk in United States minority populations. The aim of this study is to evaluate the relationship of exercise on the prevalence of polyps in a multiethnic colorectal cancer screening population.

Results

We enrolled 982 patients: 558 Hispanic, 202 Asian,149 Black, and 69 White. Patients who reported exercising one or more hours weekly had a lower prevalence of any polyps (25.3% vs 33.2%, P = 0.008) as well as adenomas (13.8 vs. 18.9%, P = 0.03) compared to those who did not exercise. Black and Hispanic patients and those who were overweight or obese also had lower prevalence of polyps if they led an active lifestyle. Multivariate analysis revealed that age >55, male sex, and Black race/ethnicity were positively associated with the presence of adenomas, while a history of exercising one hour or more weekly was an independent negative predictor for the presence of adenomas anywhere in the colon (OR 0.67; 95% CI 0.4 - 0.9, P = 0.03).

Conclusions

Exercising one hour per week was associated with a lower prevalence of polyps and adenomas when compared to those who exercised less or not at all. An active lifestyle provides benefits to groups who are at risk for colorectal cancer, such as Blacks. It also provides significant protection to overweight and obese individuals. Public health initiatives should promote physical activity as a cancer prevention tool in multiethnic populations.

Trial registration

none

Physical Activity and Colon Cancer

Despite the convincing evidence that physical activity reduces the risk of colon cancer, there are some aspects of the association that remain unclear. These include the appropriate timeframe of exposure, whether the intensity of physical activity matters, and whether sedentary behavior is a distinct risk factor. This review summarized the research that has investigated these issues. In terms of timing, physical activity at any age (with the exception of physical activity performed up to and including the late teens) has been shown to be associated with a significantly reduced risk of colon cancer. Physical activity performed between 30 and 50 years of age, as well as long-term or lifetime physical activity, has been most consistently shown to reduce risk. For intensity, research to date suggests that more intense activity (particularly vigorous activity) may be associated with a greater reduction in the risk of colon cancer for males but not for females. Finally, most of the studies that have investigated the effect of sedentary behavior on the risk of colon or colorectal cancer have shown an increased risk, suggesting that sedentary behavior may be a distinct risk factor for colon cancer.

Timing and intensity of recreational physical activity and the risk of subsite-specific colorectal cancer

PURPOSE

Although there is convincing evidence that physical activity reduces colon cancer risk, there are important questions that remain unanswered about the association. These include the timing and intensity of activity required to optimally reduce risk, and whether physical activity has a different effect on cancers at different sites within the colon. We conducted a case-control study to investigate these issues.

METHODS

A case-control study of colorectal cancer was conducted in Western Australia in 2005-2007. Data were collected on various risk factors. The estimated effects of recreational physical activity on the risk of cancers of the distal colon, proximal colon, and rectum were analyzed using multinomial logistic regression. This analysis included 870 cases and 996 controls.

RESULTS

The risk of distal colon cancer was reduced by performing a high level of vigorous-intensity activity between the ages 19 and 34 years (women), 35 and 50 years (men), after the age of 51 years (men and women), and consistently over the adult lifetime (men and women). The risk of rectal cancer was reduced by performing a high level of vigorous activity between the ages 35 and 50 years (men), and consistently over the adult lifetime (men). Proximal colon cancer risk was not associated with physical activity in any of the age periods or over the adult lifetime. Moderate intensity activity did not reduce the risk of colorectal cancer.

CONCLUSION

Physical activity may have a greater effect on the risk of distal colon cancer than proximal colon cancer. Vigorous physical activity is required to reduce colorectal cancer risk.

Colorectal cancer survivorship: movement matters

Colorectal cancer survivorship begins at diagnosis and continues throughout life. After diagnosis, survivors face the possibility of second cancers, long-term effects of cancer treatment, and comorbid conditions. Interventions that can provide primary, secondary, and tertiary prevention in this population are important. Physical activity has been shown to decrease colon cancer incidence and recurrence risk as well as improve quality of life and noncancer health outcomes including cardiovascular fitness in colon cancer survivors. The data are less robust for rectal cancer incidence and recurrence, although improvements in quality of life and health outcomes in rectal cancer survivors are also seen. Potential mechanisms for this benefit may occur through inflammatory or insulin-like growth factor pathways. The issues of colorectal cancer survivorship and the impact of physical activity on these issues are reviewed, with discussion of possible biologic mechanisms, barriers to physical activity intervention studies, and future research directions for physical activity in this burgeoning survivor population.

A systematic review of the evidence for Canada's Physical Activity Guidelines for Adults

This systematic review examines critically the scientific basis for Canada's Physical Activity Guide for Healthy Active Living for adults. Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases (cardiovascular disease, stroke, hypertension, colon cancer, breast cancer, type 2 diabetes (diabetes mellitus) and osteoporosis). The strength of the relationship between physical activity and specific health outcomes is evaluated critically. Literature was obtained through searching electronic databases (e.g., MEDLINE, EMBASE), cross-referencing, and through the authors' knowledge of the area. For inclusion in our systematic review articles must have at least 3 levels of physical activity and the concomitant risk for each chronic disease. The quality of included studies was appraised using a modified Downs and Black tool. Through this search we identified a total of 254 articles that met the eligibility criteria related to premature all-cause mortality (N = 70), cardiovascular disease (N = 49), stroke (N = 25), hypertension (N = 12), colon cancer (N = 33), breast cancer (N = 43), type 2 diabetes (N = 20), and osteoporosis (N = 2). Overall, the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified. Moreover, higher levels of physical activity reduce the risk for premature all-cause mortality. The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality.

Trends in colorectal cancer incidence in Norway 1962-2006: an interpretation of the temporal patterns by anatomic subsite

There have been rapid increases in the incidence of colorectal cancer in Norway since the 1960s, and rates rank among the highest worldwide. The primary objectives are to describe trends in left- and right-sided colon cancer and rectal cancer by calendar period and birth cohort and to generate hypotheses as to the etiological factors in operation. Although the age-adjusted incidence rates of both colon and rectal cancer increased in Norway in both sexes up to the 1980s, subsite- and age-specific analyses reveal a deceleration in the rate of increase thereafter, apparent in the rates of both left-sided colon and rectal cancer. Overall trends in incidence of right-sided colon cancer continue to increase in both sexes. Rates in both left- and right-sided colon cancers have tended to stabilize or decrease among successive generations born after 1950, however, while incidence rates of rectal cancer appear to be increasing in recent generations. The all-ages rates are thus in keeping with the commonly reported "left to right shift" of colon cancer, although standardization masks important observations. The cohort patterns provide further evidence that factors earlier in life are important, and while the complex etiology makes interpretation difficult, modifications in diet, obesity and physical activity in Norway are likely among the drivers of the trends in one or more of the colorectal subsites examined. In summary, the recent downturn in the disease at younger ages provides some reason for optimism, although possible increases in rectal cancer among recent birth cohorts are of concern.

Physical activity and gastrointestinal cancer prevention

Colorectal cancer is the third most common cancer globally and is a leading cause of cancer death. Gastric cancer contributes significantly to the global cancer burden, particularly in low- and middle-income countries. We reviewed the literature for studies on physical activity or exercise and colon, rectal, and gastric cancers as well as colonic adenomatous polyps. We identified 52 studies of colon cancer, 31 studies of rectal cancer, 23 studies of colon polyps, and 16 studies of gastric cancer. Of the 52 studies of physical activity and colon cancer, 37 found a statistically significant association between increased levels of physical activity and decreased colon cancer risk in at least one comparison. Accumulated evidence suggests that physical activity is associated with a 25% reduction in colon cancer risk. In line with previous reports, we found no indication that the association was more pronounced for occupational versus recreational physical activity, with both resulting in a risk reduction of about 22%. Evidence for other domains of physical activity (i.e., transportation or household physical activity) is limited. Evidence is emerging that individuals who are consistently active across the lifetime may obtain greater risk reductions than those who are only active in recent years. Despite consistent associations with colon cancer, evidence is more limited though suggestive that physical activity reduces risk of colon adenomas or adenoma recurrence. There is clear evidence that physical activity is not associated with rectal or gastric cancers.

Physical activity in the prevention and treatment of colorectal carcinoma

BACKGROUND

Colorectal carcinoma is the most common type of tumor in Western countries. The risk of developing colorectal carcinoma depends both on genetic factors (familial predisposition) and on lifestyle-related factors such as body-mass index, level of physical activity, and nutritional behavior. Regular physical activity is important in primary prevention, and there is also evidence that the prognosis after treatment of a colorectal carcinoma can be improved by exercise.

METHODS

The PubMed database was searched for relevant articles that appeared in the last 10 years, and selected articles were evaluated.

RESULTS

Cross-sectional studies have shown that regular physical activity (ca. 7 hours of brisk walking per week) lowers the risk of colon carcinoma by 40%. Physical activity also improves the outcome of patients already diagnosed with colorectal carcinoma: for example, patients with advanced disease (UICC stage II or III) have been found to survive significantly longer if they perform 4 hours of brisk walking per week, or the equivalent degree of physical exercise.

CONCLUSIONS

Cross-sectional studies show that physically active persons are less likely to develop colorectal carcinoma than physically inactive persons, and that they have better outcomes in the event that they do develop the disease. The positive findings with respect to secondary prevention still need to be confirmed in interventional trials, but in primary prevention, at least, physical activity should be actively promoted, along with other beneficial lifestyle habits and screening measures.

A systematic review of the association between physical activity and colorectal cancer risk

This review evaluated the strength of the evidence for a causal relationship between physical activity (PA) and colorectal cancer (CRC). A systematic review of databases through February 2008 was conducted to identify studies that assessed the association between total or recreational PA and incidence or mortality of CRC (including CRC, rectal cancer, colon cancer, and proximal or distal colon cancer). Studies were evaluated for significant associations between PA and risk of CRC endpoints and for evidence of dose-response relationships in the highest quality studies. Twenty cohort studies were evaluated; 11 were high-quality. Fifty percent of all studies and 64% of highest quality studies reported at least one significant association between PA and risk of a CRC endpoint (P<0.05). However, only 28% of all analyses (31% of analyses of highest quality studies) were significant (P<0.05). Only 40% of analyses of highest quality studies resulted in a significant P for trend (P<0.05); however, a non-significant inverse linear association between PA and colon cancer risk was apparent. Heterogeneity in the evidence from all studies and from the highest quality studies was evident. Evidence from cohort studies is not sufficient to claim a convincing relationship exists between PA and CRC risk.

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

Although higher levels of physical activity are inversely associated with risk of colon cancer, few prospective studies have evaluated overall digestive system cancer mortality in relation to cardiorespiratory fitness (CRF). The authors examined this association among 38,801 men ages 20 to 88 years who performed a maximal treadmill exercise test at baseline in the Aerobics Center Longitudinal Study (Dallas, TX) during 1974 to 2003. Mortality was assessed over 29 years of follow-up (1974-2003). Two hundred eighty-three digestive system cancer deaths occurred during a mean 17 years of observation. Age-adjusted mortality rates per 10,000 person-years according to low, moderate, and high CRF groups were 6.8, 4.0, and 3.3 for digestive system cancer (P(trend) < 0.001). After adjustment for age, examination year, body mass index, smoking, drinking, family history of cancer, personal history of diabetes, hazard ratios (95% confidence intervals) for overall digestive cancer deaths for those in the middle and upper 40% of the distribution of CRF relative to those in the lowest 20% were 0.66 (0.49-0.88) and 0.56 (0.40-0.80), respectively. Being fit (the upper 80% of CRF) was associated with a lower risk of mortality from colon [0.61 (0.37-1.00)], colorectal [0.58 (0.37-0.92)], and liver cancer [0.28 (0.11-0.72)] compared with being unfit (the lowest 20% of CRF). These findings support a protective role of CRF against total digestive tract, colorectal, and liver cancer deaths in men.

Physical activity and colon cancer prevention: a meta-analysis

Although an inverse association between physical activity and risk of colon cancer is well established, a formal estimate of the magnitude of this risk reduction that includes recent studies is not available. This analysis examines the association by sex and study design, restricting analyses to studies where data for colon cancer alone were available. The authors reviewed published studies through June 2008 examining the association between physical activity and risk of colon cancer. Heterogeneity and publication bias were evaluated and random effects models used to estimate relative risks (RR). Differences by sex and study design were evaluated. A total of 52 studies were included. An inverse association between physical activity and colon cancer was found with an overall relative risk (RR) of 0.76 (95% confidence interval (CI): 0.72, 0.81). For men, the RR was 0.76 (95% CI: 0.71, 0.82); for women, this was little different, (RR=0.79, 95% CI: 0.71, 0.88). The findings from case-control studies were stronger (RR=0.69, 95% CI: 0.65, 0.74) than for cohort studies (RR=0.83, 95% CI: 0.78, 0.88). This study confirms previous studies reporting an inverse association between physical activity and colon cancer in both men and women, and provides quantitative estimates of the inverse association.

Health benefits of physical activity in older patients: a review

As the number of elderly persons in our country increases, more attention is being given to geriatric healthcare needs and successful ageing is becoming an important topic in medical literature. Concept of successful ageing is in first line on a preventive approach of care for older people. Promotion of regular physical activity is one of the main non-pharmaceutical measures proposed to older subjects as low rate of physical activity is frequently noticed in this age group. Moderate but regular physical activity is associated with a reduction in total mortality among older people, a positive effect on primary prevention of coronary heart disease and a significant benefit on the lipid profile. Improving body composition with a reduction in fat mass, reducing blood pressure and prevention of stroke, as well as type 2 diabetes, are also well established. Prevention of some cancers (especially that of breast and colon), increasing bone density and prevention of falls are also reported. Moreover, some longitudinal studies suggest that physical activity is linked to a reduced risk of developing dementia and Alzheimer's disease in particular.

Physical inactivity is associated with chronic musculoskeletal complaints 11 years later: results from the Nord-Trøndelag Health Study

Background

Physical inactivity is associated with several diseases, but studies evaluating the association between chronic musculoskeletal complaints (MSCs) and physical exercise have shown conflicting results. The aim of this large-scale prospective population-based study was to investigate the association between self-reported physical exercise at baseline and the prevalence of chronic musculoskeletal complaints (MSCs) 11 years later.

Methods

The results are based upon two consecutive public health studies conducted within the county of Nord-Trøndelag, Norway (The HUNT studies). A total of 39,520 (83%) out of 47,556 adults who participated in HUNT 1 and HUNT 2 responded to questions about physical exercise at baseline in 1984–86, and to questions about musculoskeletal complaints 11 years later (1995–97). Chronic MSCs was defined as MSCs ≥ 3 months during the past year, and chronic widespread MSCs such as pain ≥ 15 days during the last month from the axial region, above the waist, and below the waist. Associations were assessed using multiple logistic regression, estimating prevalence odds ratio (OR) with 95% confidence intervals (CIs). All the final analyses were adjusted for age, gender, body mass index, smoking and education level.

Results

At follow-up 20,223 (51%) reported chronic MSCs, and among these 2,318 (5.9%) reported chronic widespread MSCs. Individuals who exercised at baseline were less likely to report chronic MSCs 11 years later (OR 0.91, 95% CI 0.85–0.97) than inactive persons. Among individuals who exercised more than three times per week, chronic widespread MSCs were 28% less common (OR 0.72, 95% CI 0.59–0.88) compared to inactive individuals.

Conclusion

In this large-scale population-based study, physical exercise was associated with lower prevalence of chronic MSCs, in particular chronic widespread MSCs. Future studies should try to clarify whether chronic MSCs are a cause or a consequence of inactivity.