Lifestyle changes and reduction of colon cancer incidence in Europe: A scenario study of physical activity promotion and weight reduction

Colon Cancer and Obesity: A Narrative Review

Obesity has played a crucial role in the pathogenesis of various cancers, including colorectal cancer (CRC). Obesity has shown to increase the blood levels of insulin, insulin-like growth factor-1 (IGF-1), leptin, resistin, inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1) which in turn acts via various signaling pathways to induce colonic cell proliferation and in turn CRC development. It has been shown that estrogen can prevent and cause CRC based on which receptor it acts. Obese patients have relatively low levels of ghrelin and adiponectin that inhibit cell proliferation which further adds to their risk of developing CRC. Obesity can alter the microbial flora of the gut in such a way as to favor carcinogenesis. Weight loss and good physical activity have been related to a reduced incidence of CRC; obese individuals should be screened for CRC and counseled about the importance of weight reduction, diet, and exercise. The best way of screening is using BMI and waist circumference (WC) to calculate the CRC risk in obese people. This study has reviewed the association between obesity and its pathophysiological association with CRC development.

Chinese consensus on prevention of colorectal neoplasia (2021, Shanghai)

Most patients with colorectal cancer (CRC) were diagnosed in advanced stage and the prognosis is poor. Therefore, early detection and prevention of CRC are very important. As with other cancers, there is also the tertiary prevention for CRC. The primary prevention is etiological prevention, which is mainly the treatment of adenoma or inflammation for preventing the development into cancer. The secondary prevention is the early diagnosis and early treatment for avoiding progressing to advanced cancer. The tertiary prevention belongs to the broad category of prevention, mainly for advanced CRC, through surgical treatment and postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, immunotherapy for preventing tumor recurrence or metastasis. This consensus is based on the recent domestic and international consensus guidelines and the latest progress of international researches in the past five years. This consensus opinion seminar was hosted by the Chinese Society of Gastroenterology and Cancer Collaboration Group of Chinese Society of Gastroenterology, and was organized by the Division of Gastroenterology and Hepatology & Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University. The consensus opinion contains 60 statement clauses, the standard and basis of the evidence-based medicine grade and voting grade of the statement strictly complied with the relevant international regulations and practice.

Increasing changes in visceral adiposity is associated with higher risk for colorectal adenoma: Multilevel analysis in a prospective cohort

BACKGROUND AND AIM

While many studies demonstrated an association between visceral adiposity and colorectal adenoma (CRA), the effect of longitudinal changes in body fat composition on CRA is unclear. We investigated the longitudinal association between changes in visceral adiposity and CRA occurrence.

METHODS

Between 2006 and 2018, 732 (62.8%) of the 1165 subjects in a prospective cohort voluntarily underwent follow-up abdominal fat computed tomography and colonoscopy. We defined incident and recurrent CRA as adenoma detected at follow-up colonoscopy from negative and positive adenoma at baseline colonoscopy, respectively. Multilevel survival analysis examined the longitudinal association between changes in visceral fat and CRA.

RESULTS

During a median follow-up of 7.4 years, 400 (54.6%) subjects developed CRA. In multivariable analysis, increasing changes in visceral adipose tissue (VAT) area were associated with higher risk of incident adenoma (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.00-1.46 for change per 10 cm² increase; HR 1.79, 95% CI 1.08-2.97 for highest vs lowest quartile, P values for trend = 0.045). Likewise, increasing changes in VAT area were independently associated with a higher risk of recurrent adenoma (HR 1.35, 95% CI 1.13-1.62 for change per 10 cm² increase; HR 1.62, 95% CI 1.04-2.52 for highest vs lowest quartile, P values for trend = 0.001). Changes in subcutaneous adipose tissue area were not independently associated with CRA.

CONCLUSION

Increasing changes in VAT area were longitudinally associated with a higher risk of incident and recurrent CRA, independent of risk factors, suggesting that visceral adiposity may be an important target in CRA prevention.

Tackling the cancer burden: the economic impact of primary prevention policies

Cancer is a noncommunicable disease (NCD) with increasing incidence and therefore constitutes a major public health issue. To reduce the health and economic burden of cancer, policy-makers across the world have implemented a range of preventative interventions targeting risk factors with a known link to the disease. In this article, we examine the impact of six primary prevention interventions - related to physical inactivity, unhealthy diet or harmful alcohol use - on cancer-related health outcomes and healthcare expenditure. Here, we used the OECD Strategic Public Health Planning for NCDs (SPHeP-NCDs) model to quantify outcomes and costs for each intervention for years 2020-2050 across 37 countries. Results from the model indicate that all interventions could lead to a reduction in the number of new cancer cases, in particular those targeting harmful alcohol consumption. Introducing an alcohol tax, for instance, is estimated to reduce related cancer cases by 5619 a year or 174 193 by 2050. A breakdown of results by type of cancer revealed interventions had the largest impact on colorectal cancer with, on average, 41 140 cases avoided per intervention by 2050. In proportional terms, interventions had the greatest impact on new oesophageal and liver cancers. Findings from this article are designed to assist decision-makers efficiently allocate limited resources to meet public health objectives.

Recent cancer incidence trends in Ukraine and short-term predictions to 2022

BACKGROUND

Using data from the National Cancer Registry of Ukraine (NCRU), we analyzed recent trends in incidence rates (2003-2012) and used these to predict the future cancer incidence burden up to 2022.

METHODS

All cancer cases (excluding non-melanoma of skin) for the years 2003-2012 were retrieved from the NCRU's database (n = 1,459,851). Age-standardized incidence rates (ASRs) were estimated and the numbers of new cases and incidence rates predicted for 2022 using age-period modeling.

RESULTS

ASR increased from 2003 to 2012 for most cancers except lip and stomach cancers (in both sexes) and laryngeal and lung cancers (in males). Assuming these trends will continue, lung cancer will remain the most common male cancer in 2022 (ASR 40.5/100,000), followed by prostate cancer (36.8/100,000), colorectal cancer (34.6/100,000), and cancers of the oral cavity and pharynx (18.5/100,000). In females, the order of the four most common cancers will not change in 2022 compared with 2012, with cervical cancer remaining the fourth most common cancer (17.5/100,000). We predict an overall increase of 18 % in the number of cancer cases in Ukraine (relative to 2012) to 179,493 cases in 2022.

CONCLUSION

The anticipated increase in the number of cancer patients in Ukraine clearly has knock-on effects on a healthcare system undergoing reforms. Tobacco control appears to be the only functioning aspect of cancer prevention in the country, and there is a need for a broader national cancer control plan. The continued monitoring and evaluation of implemented cancer control measures by the NCRU will help prioritize targets and allocate future resources to cancer services.

The Role of Self-Determination in Changing Physical Activity Behavior in People Diagnosed With Bowel Polyps: A Pilot Randomized Controlled Trial

This nonblinded randomized controlled trial investigated the efficacy of a physical activity (PA) intervention underpinned by self-determination theory. Participants (N = 31, mean age 69 years [SD = 4.9]) diagnosed with bowel polyps were randomized to an active lifestyle program (ALP; n = 17) or standard care (n = 14). ALP received supervised exercise and counseling for 6 months. Both groups were followed up at 12 months. Outcomes were change in PA and behavioral regulation. Data were analyzed with intention to treat. At 6 months, differences were observed for behavioral regulation in favor of ALP (p < .05). PA differences were significant for leisure, walking, and vigorous in favor of ALP (p < .05). The self-determination theory can be an effective strategy for promoting PA behavior change in this population, but a larger trial is needed to further explore the utility of the self-determination theory in this context.

Revisiting the impact of lifestyle on colorectal cancer risk in a gender perspective

Colorectal cancer (CRC) is a leading cause of cancer-related mortality in the world. Patterns and trends in CRC incidence and mortality correlate with increasing adoption of Western lifestyles and with the overweight/obesity epidemic. Both genetic background and a range of modifiable environmental/lifestyle factors play a role in CRC etiology. Among these the links of body weight, dietary patterns and physical activity (PA) behavior with CRC risk are some of the strongest for any type of cancer, with a different impact in women and men. Nonetheless, gender disparities still represent a neglected aspect of CRC management. This review sheds light on gender-related association of obesity and different dietary/PA habits with CRC risk, highlighting the importance of lifestyle modifications in the prevention of this neoplastic disease. In this scenario, intervention studies are strongly recommended to define the most effective dietary/PA regimens for primary prevention of cancer in women and men.

Avoidable cancers in the Nordic countries-the potential impact of increased physical activity on postmenopausal breast, colon and endometrial cancer

BACKGROUND

Physical activity has been shown to reduce the risk of colon, endometrial and postmenopausal breast cancer. The aim of this study was to quantify the proportion of the cancer burden in the Nordic countries linked to insufficient levels of leisure time physical activity and estimate the potential for cancer prevention for these three sites by increasing physical activity levels.

METHODS

Using the Prevent macrosimulation model, the number of cancer cases in the Nordic countries over a 30-year period (2016-2045) was modelled, under different scenarios of increasing physical activity levels in the population, and compared with the projected number of cases if constant physical activity prevailed. Physical activity (moderate and vigorous) was categorised according to metabolic equivalents (MET) hours in groups with sufficient physical activity (15+ MET-hours/week), low deficit (9 to <15 MET-hours/week), medium deficit (3 to <9 MET-hours/week) and high deficit (<3 MET-hours/week).

RESULTS

If no one had insufficient levels of physical activity, about 11,000 colon, endometrial and postmenopausal breast cancer cases could be avoided in the Nordic countries in a 30-year period, which is 1% of the expected cases for the three cancer types. With a 50% reduction in all deficit groups by 2025 or a 100% reduction in the group of high deficit, approximately 0.5% of the expected cases for the three cancer types could be avoided. The number and percentage of avoidable cases was highest for colon cancer.

CONCLUSION

11,000 cancer cases could be avoided in the Nordic countries in a 30-year period, if deficit in physical activity was eliminated.

Physical activity, mediating factors and risk of colon cancer: insights into adiposity and circulating biomarkers from the EPIC cohort

Background

There is convincing evidence that high physical activity lowers the risk of colon cancer; however, the underlying biological mechanisms remain largely unknown. We aimed to determine the extent to which body fatness and biomarkers of various biologically plausible pathways account for the association between physical activity and colon cancer.

Methods

We conducted a nested case-control study in a cohort of 519 978 men and women aged 25 to 70 years followed from 1992 to 2003. A total of 713 incident colon cancer cases were matched, using risk-set sampling, to 713 controls on age, sex, study centre, fasting status and hormonal therapy use. The amount of total physical activity during the past year was expressed in metabolic equivalent of task [MET]-h/week. Anthropometric measurements and blood samples were collected at study baseline.

Results

High physical activity was associated with a lower risk of colon cancer: relative risk ≥91 MET-h/week vs <91 MET-h/week = 0.75 [95% confidence interval (CI): 0.57 to 0.96]. In mediation analyses, this association was accounted for by waist circumference: proportion explained effect (PEE) = 17%; CI: 4% to 52%; and the biomarkers soluble leptin receptor (sOB-R): PEE = 15%; 95% CI: 1% to 50% and 5-hydroxyvitamin D (25[OH]D): PEE = 30%; 95% CI: 12% to 88%. In combination, these factors explained 45% (95% CI: 20% to 125%) of the association. Beyond waist circumference, sOB-R and 25[OH]D additionally explained 10% (95% CI: 1%; 56%) and 23% (95% CI: 6%; 111%) of the association, respectively.

Conclusions

Promoting physical activity, particularly outdoors, and maintaining metabolic health and adequate vitamin D levels could represent a promising strategy for colon cancer prevention.

Cohort profile: a nationwide cohort of Finnish military recruits born in 1958 to study the impact of lifestyle factors in early adulthood on disease outcomes

PURPOSE

The cohort was set up to study the impact of lifestyle factors in early adulthood on disease outcomes, with a focus on assessing the influence of body composition and physical performance in early adulthood on subsequent cancer risk.

PARTICIPANTS

Men born in 1958 who performed their military service between the ages of 17 and 30 years were included in this study (n=31 158). They were eligible for military service if they were healthy or had only minor health problems diagnosed at the beginning of their service. Men with chronic illnesses requiring regular medication or treatment were not eligible for service. Comprehensive health data including diagnosed illnesses, anthropometric measures and health behaviour were collected at the beginning and at the end of military service, including data from medical check-ups.

FINDINGS TO DATE

During the follow-up, 1124 new cancer cases were diagnosed between baseline (ie, end of the military service for each individual) and end of the year 2014. In the end of the follow-up, 91% of the study participants were still alive. Overweight (body mass index (BMI) ≥25 kg/m2) and obesity (BMI ≥30 kg/m2) were associated with an overall increased risk of cancer. A good or excellent physical condition significantly reduced cancer risk.

FUTURE PLANS

The dataset offers the possibility of linkage with other databases, such as the Finnish Cancer Registry (eg, primary site of the tumour, morphology, time of detection, spreading and primary treatment), vital statistics (date of emigration or deaths), censuses (socioeconomic indicators), hospital discharge data (comorbidity) and population surveys (life habits).

How Many Deaths from Colorectal Cancer Can Be Prevented by 2030? A Scenario-Based Quantification of Risk Factor Modification, Screening, and Treatment in Norway

Background: Colorectal cancer mortality can be reduced through risk factor modification (adherence to lifestyle recommendations), screening, and improved treatment. This study estimated the potential of these three strategies to modify colorectal cancer mortality rates in Norway.Methods: The potential reduction in colorectal cancer mortality due to risk factor modification was estimated using the software Prevent, assuming that 50% of the population in Norway-who do not adhere to the various recommendations concerning prevention of smoking, physical activity, body weight, and intake of alcohol, red/processed meat, and fiber-started to follow the recommendations. The impact of screening was quantified assuming implementation of national flexible sigmoidoscopy screening with 50% attendance. The reduction in colorectal cancer mortality due to improved treatment was calculated assuming that 50% of the linear (positive) trend in colorectal cancer survival would continue to persist in future years.Results: Risk factor modification would decrease colorectal cancer mortality by 11% (corresponding to 227 prevented deaths: 142 men, 85 women) by 2030. Screening and improved treatment in Norway would reduce colorectal cancer mortality by 7% (149 prevented deaths) and 12% (268 prevented deaths), respectively, by 2030. Overall, the combined effect of all three strategies would reduce colorectal cancer mortality by 27% (604 prevented deaths) by 2030.Conclusions: Risk factor modification, screening, and treatment all have considerable potential to reduce colorectal cancer mortality by 2030, with the largest potential reduction observed for improved treatment and risk factor modification.Impact: The estimation of these health impact measures provides useful information that can be applied in public health decision-making. Cancer Epidemiol Biomarkers Prev; 26(9); 1420-6. ©2017 AACR.

Obesity as an Avoidable Cause of Cancer (Attributable Risks)

Excess body weight, commonly categorised as overweight (body mass index, BMI 25.0-29.9 kg/m2) and obesity (BMI ≥30 kg/m2) is an established risk factor for increased incidence of several adult cancers. As body weight is modifiable, there is a potential for cancer prevention. Calculation of attributable risk (here expressed at population attributable fraction, PAF) offers an estimate of the burden of excess cancers attributable to elevated BMI in populations, and thus an approximation of avoidable cases and the opportunity for prevention. Using counterfactual methods, the estimated PAF worldwide attributed to elevated BMI is 3.6 % or nearly half a million new cancer cases in adults (aged 30 years and older after a 10-year lag period). PAFs are higher in women compared with men (5.4 % vs. 1.9 %). Endometrial, post-menopausal breast, and colon cancers account for nearly two-thirds of cancers attributable to elevated BMI. Globally, excess body weight is the third commonest attributable risk factor for cancer (after smoking and infection); in western populations such as the UK, excess weight ranks as second commonest risk factor.

Avoidable cancer cases in the Nordic countries - The impact of overweight and obesity

BACKGROUND

Several types of cancers are causally linked to overweight and obesity, which are increasing in the Nordic countries. The aim of this study was to quantify the proportion of the cancer burden linked to overweight and obesity in the Nordic countries and estimate the potential for cancer prevention.

METHODS

Under different prevalence scenarios of overweight and obesity, the number of cancer cases in the Nordic countries in the next 30 years (i.e. 2016-2045) was estimated for 13 cancer sites and compared to the projected number of cancer cases if the prevalence stayed constant. The Prevent macro-simulation model was used.

RESULTS

Over the period 2016-2045, 205,000 cancer cases out of the 2.1 million expected for the 13 cancer sites (9.5%) that have been studied, could be avoided in the Nordic countries by totally eliminating overweight and obesity in the target population. The largest proportional impact was found for oesophageal adenocarcinoma (24%), and the highest absolute impact was observed for colon (44638) and postmenopausal breast cancer (41135).

CONCLUSION

Decreased prevalence of overweight and obesity would reduce the cancer burden in the Nordic countries. The results from this study form an important step to increase awareness and priorities in cancer control by controlling overweight and obesity in the population.

Potential health gains and health losses in eleven EU countries attainable through feasible prevalences of the life-style related risk factors alcohol, BMI, and smoking: a quantitative health impact assessment

BACKGROUND

Influencing the life-style risk-factors alcohol, body mass index (BMI), and smoking is an European Union (EU) wide objective of public health policy. The population-level health effects of these risk-factors depend on population specific characteristics and are difficult to quantify without dynamic population health models.

METHODS

For eleven countries-approx. 80 % of the EU-27 population-we used evidence from the publicly available DYNAMO-HIA data-set. For each country the age- and sex-specific risk-factor prevalence and the incidence, prevalence, and excess mortality of nine chronic diseases are utilized; including the corresponding relative risks linking risk-factor exposure causally to disease incidence and all-cause mortality. Applying the DYNAMO-HIA tool, we dynamically project the country-wise potential health gains and losses using feasible, i.e. observed elsewhere, risk-factor prevalence rates as benchmarks. The effects of the "worst practice", "best practice", and the currently observed risk-factor prevalence on population health are quantified and expected changes in life expectancy, morbidity-free life years, disease cases, and cumulative mortality are reported.

RESULTS

Applying the best practice smoking prevalence yields the largest gains in life expectancy with 0.4 years for males and 0.3 year for females (approx. 332,950 and 274,200 deaths postponed, respectively) while the worst practice smoking prevalence also leads to the largest losses with 0.7 years for males and 0.9 year for females (approx. 609,400 and 710,550 lives lost, respectively). Comparing morbidity-free life years, the best practice smoking prevalence shows the highest gains for males with 0.4 years (342,800 less disease cases), whereas for females the best practice BMI prevalence yields the largest gains with 0.7 years (1,075,200 less disease cases).

CONCLUSION

Smoking is still the risk-factor with the largest potential health gains. BMI, however, has comparatively large effects on morbidity. Future research should aim to improve knowledge of how policies can influence and shape individual and aggregated life-style-related risk-factor behavior.

Assessment of rehabilitation needs in colorectal cancer treatment: Results from a mixed audit and qualitative study in Denmark

Background Systematic assessments of cancer patients' rehabilitation needs are a prerequisite for devising appropriate survivorship programs. Little is known about the fit between needs assessment outlined in national rehabilitation policies and clinical practice. This study aimed to explore clinical practices related to identification and documentation of rehabilitation needs among patients with colorectal cancer at Danish hospitals. Material and methods A retrospective clinical audit was conducted utilizing data from patient files randomly selected at surgical and oncology hospital departments treating colorectal cancer patients. Forty patients were included, 10 from each department. Semi-structured interviews were carried out among clinical nurse specialists. Audit data was analyzed using descriptive statistics, qualitative data using thematic analysis. Results Documentation of physical, psychological and social rehabilitation needs initially and at end of treatment was evident in 10% (n = 2) of surgical patient trajectories and 35% (n = 7) of oncology trajectories. Physical rehabilitation needs were documented among 90% (n = 36) of all patients. Referral to municipal rehabilitation services was documented among 5% (n = 2) of all patients. Assessments at surgical departments were shaped by the inherent continuous assessment of rehabilitation needs within standardized fast-track colorectal cancer surgery. In contrast, the implementation of locally developed assessment tools inspired by the distress thermometer (DT) in oncology departments was challenged by a lack of competencies and funding, impeding integration of data into patient files. Conclusion Consensus must be reached on how to ensure more systematic, comprehensive assessments of rehabilitation needs throughout clinical cancer care. Fast-track surgery ensures systematic documentation of physical needs, but the lack of inclusion of data collected by the DT in oncological departments questions the efficacy of assessment tools and points to a need for distinguishing between surgical and oncological settings in national rehabilitation policies.

Exercise and Self-Reported Limitations in Patients with Inflammatory Bowel Disease

BACKGROUND

Limited evidence suggests that exercise may have beneficial, anti-inflammatory effects in patients with inflammatory bowel disease (IBD).

AIMS

The purpose of this study was to evaluate the prevalence of exercise in patients with IBD and the limitations they experience secondary to their disease.

METHODS

Two hundred and fifty IBD patients were prospectively enrolled in this study at an academic medical center at the time of their outpatient visits between March and October 2013. Subjects were asked to complete a one-time survey that asks questions about medical and surgical history, exercise frequency and intensity, and the limitations and barriers they experience.

RESULTS

Two hundred and twenty-seven patients (148 female patients) completed the survey. Crohn's disease was present in 140 patients (61.5 %), while 87 had ulcerative colitis. Forty-one patients (16.4 %) never exercised, 82 patients (32.8 %) exercised 1-2 times per week, 59 (23.6 %) exercised 3-4 times per week, and 45 (18.0 %) exercised more than four times per week. Of the 186 who regularly exercise, 95 (51 %) reported moderate exercise intensity, 61 (33 %) reported light intensity, and 30 (16 %) reported vigorous intensity. Ninety-nine patients (44 %) reported that their IBD limited their exercise for reasons including fatigue (n = 81), joint pain (n = 37), embarrassment (n = 23), weakness (n = 21), and others.

CONCLUSIONS

Although they may benefit from exercise, IBD patients experience considerable barriers to regular exercise secondary to the relapsing and remitting nature of IBD. Larger studies are needed to determine the effects of exercise on disease symptomatology and activity.

Do recent epidemiologic observations impact who and how we should screen for CRC?

Colorectal cancer (CRC) screening is recommended to begin at age 50 for those patients with no significant family history of CRC. However, even within this group of average-risk patients, there is data to suggest that there may be variation in CRC risk. These observations suggest that perhaps CRC screening should be tailored to target those patients at higher risk for earlier or more invasive screening as compared to those individuals at lower risk. The strategy of how to identify those higher-risk patients may not be straightforward. One method might be to use single risk factors such as smoking or elevated BMI as has been suggested in the recent American College of Gastroenterology CRC screening guidelines. Another paradigm involves the use of models which incorporate several risk factors to stratify patients by risk. This article will highlight recent large studies that examine recognized CRC risk factors as well as review recently developed CRC risk models. There will also be a discussion of the application of these factors and models in an effort to make CRC screening more efficient.

Iodine-125 induces apoptosis via regulating p53, microvessel density, and vascular endothelial growth factor in colorectal cancer

Background

Iodine interstitial brachytherapy has been widely reported for treating colorectal cancer (CRC). However, the inhibitory molecular mechanism of iodine-125 (I-125) on CRC has not been reported.

Methods

To illustrate the inhibitory mechanism of iodine-125 (I-125) on CRC, we established the animal models of CRC via the injection of HCT-8 cells into nude mice. Subsequently, the I-125 granules were implanted into the tumor of the animal model at different dosages. Proliferating cell nuclear antigen and terminal transferase dUTP nick end labeling were used to detect the apoptosis of the tumor cells. Immunohistochemistry SP staining was used to measure the expression of p53 protein. The protein levels were examined with western blot and ELISA. Meanwhile, microvessel density (MVD) was counted by endothelial cells immunostained by anti-CD34 antibody.

Results

The results showed that I-125 protests against CRC via increasing the protein level of p53 and decreasing the level of vascular endothelial growth factor (VEGF), leading to the decrease of MVD in CRC (P <0.0001). An effective inhibition dosage of I-125 ranged from 0.4 to 0.8 mCi.

Conclusions

The inhibitory mechanisms of iodine on CRC acted through an increase in the level of p53 and a decrease in the level of VEGF, resulting in a decrease of MVD.

Correlation of cancer incidence with diet, smoking and socio- economic position across 22 districts of Tehran in 2008

BACKGROUND

Variation in cancer incidence in geographical locations is due to different lifestyles and risk factors. Diet and socio-economic position (SEP) have been identified as important for the etiology of cancer but patterns are changing and inconsistent. The aim of this study was to investigate correlations of the incidence of common cancers with food groups, total energy, smoking, and SEP.

MATERIALS AND METHODS

In an ecological study, disaggregated cancer data through the National Cancer Registry in Iran (2008) and dietary intake, smoking habits and SEP obtained through a population based survey within the Urban Health Equity Assessment (Urban-HEART) project were correlated across 22 districts of Tehran.

RESULTS

Consumption of fruit, meat and dairy products adjusted for energy were positively correlated with bladder, colorectal, prostate and breast and total cancers in men and women, while these cancers were adversely correlated with bread and fat intake. Also prostate, breast, colorectal, bladder and ovarian cancers had a positive correlation with SEP; there was no correlation between SEP and skin cancer in both genders and stomach cancer in men.

CONCLUSIONS

The incidence of cancer was higher in some regions of Tehran which appeared to be mainly determined by SEP rather than dietary intake. Further individual data are required to investigate reasons of cancer clustering.

Mechanisms linking excess adiposity and carcinogenesis promotion

Obesity constitutes one of the most important metabolic diseases being associated to insulin resistance development and increased cardiovascular risk. Association between obesity and cancer has also been well established for several tumor types, such as breast cancer in post-menopausal women, colorectal, and prostate cancer. Cancer is the first death cause in developed countries and the second one in developing countries, with high incidence rates around the world. Furthermore, it has been estimated that 15-20% of all cancer deaths may be attributable to obesity. Tumor growth is regulated by interactions between tumor cells and their tissue microenvironment. In this sense, obesity may lead to cancer development through dysfunctional adipose tissue and altered signaling pathways. In this review, three main pathways relating obesity and cancer development are examined: (i) inflammatory changes leading to macrophage polarization and altered adipokine profile; (ii) insulin resistance development; and (iii) adipose tissue hypoxia. Since obesity and cancer present a high prevalence, the association between these conditions is of great public health significance and studies showing mechanisms by which obesity lead to cancer development and progression are needed to improve prevention and management of these diseases.

Recent trends in incidence of five common cancers in 26 European countries since 1988: Analysis of the European Cancer Observatory

BACKGROUND

Individual country- and cancer site-specific studies suggest that the age-adjusted incidence of many common cancers has increased in European populations over the past two decades. To quantify the extent of these trends and the recent burden of cancer, here we present a comprehensive overview of trends in population-based incidence of the five common cancers across Europe derived from a new web-based portal of the European cancer registries.

METHODS

Data on incidence for cancers of the colon and rectum, prostate, breast, corpus uteri and stomach diagnosed from 1988 to 2008 were obtained from the European Cancer Observatory for cancer registries from 26 countries. Annual age-standardised incidence rates and average annual percentage changes were calculated.

RESULTS

Incidence of four common cancers in eastern and central European countries (prostate, postmenopausal breast, corpus uteri and colorectum) started to approach levels in northern and western Europe, where rates were already high in the past but levelled off in some countries in recent years. Decreases in stomach cancer incidence were seen in all countries.

DISCUSSION

Increasing trends in incidence of the most common cancers, except stomach cancer, are bad news to public health but can largely be explained by well-known changes in society in the past decades. Thus, current and future efforts in primary cancer prevention should not only remain focussed on the further reduction of smoking but engage in the long-term efforts to retain healthy lifestyles, especially avoiding excess weight through balanced diets and regular physical exercise.

Receptivity and Preferences in Cancer Risk Reduction Lifestyle Programs: A Survey of Colorectal Cancer Family Members

BACKGROUND

Cancer is a shared family experience, and thus the purpose of this study was to assess receptivity and preferences for cancer risk reduction programs among at-risk family members with two or more relatives affected with colorectal cancer (CRC).

METHODS

The sample comprised 401 at-risk family members with two or more relatives affected with CRC from the Colon Cancer Family Registry. In March 2009, respondents completed a mailed survey assessing receptivity and preferences for participating in cancer risk reduction programs and evaluated their relationship to demographic, medical, and psychosocial variables. Multivariable generalized estimating equation approaches were used to model preferences.

RESULTS

Overall, 81% of respondents were receptive to a lifestyle cancer risk reduction program; of these, about half (54%) preferred to participate with their family. Program preferences included: weight management (36%) and nutrition (31%); delivered through the internet (41%) or mail (39%). In a multivariate model, a greater level of concern about cancer (p<0.001), female gender (p=0.002), and higher education (p=0.016) were significantly correlated with willingness to participate in lifestyle programs.

CONCLUSIONS

Family members of those with CRC are receptive to cancer risk reduction programs that focus on weight management and nutrition delivered via the internet or mail. Future research is needed to determine how best to incorporate a family-based approach that addresses the cancer experience when designing lifestyle intervention programs.

Body mass index at different adult ages, weight change, and colorectal cancer risk in the National Institutes of Health-AARP Cohort

The authors investigated the relations of body mass index at different ages and adult weight change to incident colorectal cancer risk in the prospective National Institutes of Health-AARP Diet and Health Study (1995-1996), using a subcohort with repeated recall weights (273,679 participants; mean baseline age = 62.8 years). During 2,509,662 person-years follow-up, 4076 incident colorectal cancers were ascertained. For men, an increased risk of colon cancer but not rectal cancer was associated with body mass index at baseline age (per 5-kg/m(2) increase, hazard ratio (HR) = 1.18, 95% confidence interval (CI): 1.11, 1.25), at age 50 years (HR = 1.18, 95% CI: 1.10, 1.26), and at age 35 years (HR = 1.16, 95% CI: 1.07, 1.25) but less so at age 18 years. Weight gained between the ages of 18 and 35 years and between 18 years of age and the baseline age was associated with an increased risk of colon cancer in men (per 0.5-kg/year increase, HR = 1.18, 95% CI: 1.11, 1.25 and HR = 1.29, 95% CI: 1.16, 1.56, respectively). For women, relations throughout were weaker than those observed for men. These findings suggest that weight gains during early to middle adulthood have important influences on colon cancer risk, especially in men.

Potential impact of interventions resulting in reduced exposure to ultraviolet (UV) radiation (UVA and UVB) on skin cancer incidence in four European countries, 2010-2050

BACKGROUND

Behavioural interventions to reduce exposure to ultraviolet radiation (UVR) can reduce risk of skin cancer.

OBJECTIVES

To integrate the data and to evaluate the impact of interventions to limit exposure to UVR on skin cancer incidence in four selected countries.

METHODS

Using PREVENT, a dynamic simulation model, we modelled the potential for skin cancer prevention in four European countries under various scenarios to avoid damage by UVR.

RESULTS

In general, the most effective interventions were those aimed at protecting people during outdoor work and outdoor hobbies against the harmful effects of UVR, and combinations of several interventions. These could in theory lead to reductions of up to 45% in skin cancer cases projected for the year 2050.

CONCLUSIONS

The scope for prevention depends on the prevalence of the risk factors in the different countries, as well as the associated risk factors and time lags modelled.

Body mass index increases risk for colorectal adenomas based on meta-analysis

BACKGROUND & AIMS

There have been inconsistent results published about the relationship between excess body weight, expressed as increased body mass index (BMI), and risk of colorectal adenoma (CRA). We conducted a meta-analysis to explore this relationship. We focused on whether the relationship varied based on the sex of the study subjects, study design, features of the polyps, or potential confounders, including alcohol use, nonsteroidal anti-inflammatory drug use, smoking, and exercise.

METHODS

We identified studies by performing a literature search of Medline, EMBASE, and ISI Web of Science through July 31, 2011, and by searching the reference lists of pertinent articles. We analyzed 36 independent studies, which included 29,860 incident cases of CRA. Summary relative risks with their 95% confidence intervals (CIs) were calculated with a random-effects model. Between-study heterogeneity was assessed using Cochran's Q statistic and I(2) analyses.

RESULTS

Overall, a 5-unit increase in BMI (calculated as kg/m(2)) increased the risk for CRA (summary relative risk = 1.19; 95% CI: 1.13-1.26), although there was a high level of heterogeneity among studies (P(heterogeneity) < .001; I(2) = 76.8%). Subgroup analyses revealed that the increased risk of CRA in obese individuals was independent of race, geographic location, study design, sex, adenoma progression, and confounders. The association between increased BMI and risk for CRA was stronger for colon than rectal adenoma.

CONCLUSIONS

Based on a meta-analysis, increased BMI increases the risk for colon but not rectal adenoma. Unlike colorectal cancer, there is no sex difference in the relationship between increased BMI and risk of CRA.

Screening for colorectal cancer: possible improvements by risk assessment evaluation?

Emerging results indicate that screening improves survival of patients with colorectal cancer. Therefore, screening programs are already implemented or are being considered for implementation in Asia, Europe and North America. At present, a great variety of screening methods are available including colono- and sigmoidoscopy, CT- and MR-colonography, capsule endoscopy, DNA and occult blood in feces, and so on. The pros and cons of the various tests, including economic issues, are debated. Although a plethora of evaluated and validated tests even with high specificities and reasonable sensitivities are available, an international consensus on screening procedures is still not established. The rather limited compliance in present screening procedures is a significant drawback. Furthermore, some of the procedures are costly and, therefore, selection methods for these procedures are needed. Current research into improvements of screening for colorectal cancer includes blood-based biological markers, such as proteins, DNA and RNA in combination with various demographically and clinically parameters into a "risk assessment evaluation" (RAE) test. It is assumed that such a test may lead to higher acceptance among the screening populations, and thereby improve the compliances. Furthermore, the involvement of the media, including social media, may add even more individuals to the screening programs. Implementation of validated RAE and progressively improved screening methods may reform the cost/benefit of screening procedures for colorectal cancer. Therefore, results of present research, validating RAE tests, are awaited with interest.

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.

Excess body weight and obesity--the link with gastrointestinal and hepatobiliary cancer

Excess body weight (EBW) is an independent risk factor for many human malignancies, including cancers throughout the gastrointestinal and hepatobiliary tract from the esophagus to the colorectum. The relative risk of gastrointestinal cancer in obese individuals is approximately 1.5-2.0 times that for normal weight individuals, with organ-specific and gender-specific differences for specific cancers. The association between EBW and risk of premalignant stages of gastrointestinal carcinogenesis, such as colorectal adenoma and Barrett esophagus, is similar, implying a role for EBW during the early stages of carcinogenesis that could be relevant to preventative strategies. EBW also impacts negatively on gastrointestinal cancer outcomes. The mechanistic basis of the association between EBW and carcinogenesis remains incompletely understood. Postulated mechanisms include increased insulin and insulin-like growth factor signaling and chronic inflammation (both linked to the metabolic syndrome), as well as signaling via adipokines, such as leptin. The role of obesity-related changes in the intestinal microbiome in gastrointestinal carcinogenesis deserves further attention. Whether weight loss leads to reduced future gastrointestinal and liver cancer risk has yet to be fully explored. There is some support for the idea that weight loss negatively regulates colorectal carcinogenesis. In addition, data suggest a reduction in risk of several cancers in the first 10 years after bariatric surgery.

State of the epidemiological evidence on physical activity and cancer prevention

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Foreword: Implementing cancer prevention in Europe

The understanding of risk factors underpinning the aetiology of many common cancers is well established, yet the conversion of this knowledge into prevention lags considerably behind. The title of this Special Issue - Implementing cancer prevention in Europe - captures the central theme within; namely, the translation of cancer epidemiology into public health policy. The Special Issue is supported by focused evidence-based case studies of how these processes might be best taken forward.