Weight, dietary behavior, and physical activity in childhood and adolescence: implications for adult cancer risk

Adolescent cancer prevention in rural, pediatric primary care settings in the United States: A scoping review

Adolescence is a critical period for establishing habits and engaging in health behaviors to prevent future cancers. Rural areas tend to have higher rates of cancer-related morbidity and mortality as well as higher rates of cancer-risk factors among adolescents. Rural primary care clinicians are well-positioned to address these risk factors. Our goal was to identify existing literature on adolescent cancer prevention in rural primary care and to classify key barriers and facilitators to implementing interventions in such settings. We searched the following databases: Ovid MEDLINE®; Ovid APA PsycInfo; Cochrane Library; CINAHL; and Scopus. Studies were included if they reported on provider and/or clinic-level interventions in rural primary care clinics addressing one of these four behaviors (obesity, tobacco, sun exposure, HPV vaccination) among adolescent populations. We identified 3,403 unique studies and 24 met inclusion criteria for this review. 16 addressed obesity, 6 addressed HPV vaccination, 1 addressed skin cancer, and 1 addressed multiple behaviors including obesity and tobacco use. 10 studies were either non-randomized experimental designs (n = 8) or randomized controlled trials (n = 2). The remaining were observational or descriptive research. We found a dearth of studies addressing implementation of adolescent cancer prevention interventions in rural primary care settings. Priorities to address this should include further research and increased funding to support EBI adaptation and implementation in rural clinics to reduce urban-rural cancer inequities.

Associations between GoSmart Channel, health literacy and health behaviours in adolescents: A population-based study

BACKGROUND

Health literacy is essential in the promotion of healthy lifestyle habits and chronic disease prevention.

OBJECTIVE

To assess the health literacy level among Hong Kong adolescents; to evaluate the association between access of an online health information platform (GoSmart Channel) and health literacy level; and to examine the association between health literacy level and various unhealthy behaviours.

DESIGN

This study recruited students from 10 local secondary schools in Hong Kong to assess the health literacy level among adolescents.

SETTINGS AND PARTICIPANTS

Participants were required to complete a self-administered questionnaire on health behaviours and health literacy using the Health Literacy Measure for Adolescents (HELMA). MAIN OUTCOME MEASURE: Data were analysed using descriptive statistics and multivariate regression modelling.

RESULTS

A total of 777 responses were collected. Overall, most (74.4%) of the adolescents in Hong Kong have limited health literacy (HELMA score <66). The majority (63.7%) of adolescents relied on their parents for health information, while 11.4% of the respondents sought information from the GoSmart Channel. The intervention of GoSmart Channel was significantly associated with better health literacy in almost all aspects among adolescents. Desired levels of health literacy were significantly associated with better perceived health (adjusted odds ratio: 2.04, p = .001) and negatively associated with a range of unhealthy and risky behaviours including unhealthy dietary habits, poor hygienic measures and physical inactivity.

DISCUSSION AND CONCLUSION

This study highlights the importance of improving health literacy among Hong Kong adolescents and the potential of technology-based interventions. The findings suggest the need for continued efforts to promote health literacy and healthy behaviours among adolescents, especially given the limited health literacy levels observed in the study.

PATIENT OR PUBLIC CONTRIBUTION

Members of the GoSmart.Net Built-on Project patient and public involvement and engagement group advised about survey development.

Food purchasing practices in various retail settings and dietary intake: A cross-sectional survey of Australian adolescents

BACKGROUND/AIMS

Discretionary, energy-dense, nutrient-poor food and drinks are heavily marketed and readily available in retail settings frequented by adolescents. This study examines associations between food purchasing practices in various retail settings and dietary intake among Australian adolescents.

METHODS

Participants were students in years 8 to 11 (ages 12-17 years) who completed the 2009-10 (n = 13 790), 2012-13 (n = 10 309) or 2018 (n = 9102) National Secondary Students' Diet and Activity (NaSSDA) cross-sectional survey. Multistage stratified random sampling was used. An online survey completed at school assessed self-reported frequency of food purchasing practices in various retail settings and consumption of discretionary food, sugary drinks, fruit and vegetables. Generalised linear regression models examined associations between food purchasing practices and dietary behaviour.

RESULTS

Relative to students who brought lunch from home, those who purchased lunch from school or nearby outlets reported higher intake of discretionary food and sugary drinks and lower fruit intake. Buying lunch from school was also associated with lower vegetable intake. Buying food or drinks on the school commute, outside school grounds during school hours, from supermarket checkouts, and using mobile phone apps were each associated with higher discretionary food and sugary drink intake (all P < .01).

CONCLUSIONS

Purchasing food or drink in various retail settings is associated with higher intake of discretionary food and drink among Australian adolescents, and some purchasing practices appeared to displace fruit and vegetable intake. SO WHAT?: These findings highlight a need to improve the accessibility and promotion of healthier food and drink options in schools and other retail settings.

Impact of Moderate-Vigorous Physical Activity Trajectories on Colon Cancer Risk over the Adult Life Course

BACKGROUND

Moderate-vigorous physical activity (MVPA) reduces colon cancer risk; however, it is unclear how the timing of MVPA throughout the adult life course impacts colon cancer risk. We evaluated whether maintenance and changes in MVPA levels over time are associated with colon cancer risk.

METHODS

We assessed 293,198 adults ages 50 to 71 years in the NIH-AARP Diet and Health Study. Participants completed baseline health and physical activity questionnaires between 1995 and 1997 and were followed through 2011, (average follow-up of 13.1 years). There were 5,072 colon cancer cases over the study period. Using latent class trajectory models, we identified seven distinct MVPA trajectories across the adult life course (15-18, 19-29, 30-35, and past 10-years) and ran Cox proportional hazards regression models.

RESULTS

Compared with those who maintained low MVPA levels, those who maintained high and moderate levels of MVPA had a lower risk of colon cancer [HR, 0.85; confidence interval (CI), 0.78-0.93; HR = 0.87; CI, 0.76-1.00)], and those who increased MVPA levels early and later during adulthood had a lower colon cancer risk (HR, 0.90; CI, 0.80-1.01) and (HR, 0.92; CI, 0.80-1.06), respectively. Those who decreased MVPA early in adulthood had an increased risk of colon cancer (HR, 1.12; CI, 1.02-1.23). These associations were stronger in adults ages <65 years at baseline and in men (P < 0.001).

CONCLUSIONS

Consistent participation in MVPA throughout life may reduce colon cancer risk.

IMPACT

These findings emphasize that engaging in MVPA throughout adulthood lowers risk of colon cancer.

Health behaviors in adolescent survivors of cancer: An integrative review

PROBLEM

Adolescent survivors of cancer face an increased risk of chronic health conditions that can be improved by healthy behaviors. The purpose of this review is to synthesize the extent/prevalence of health behaviors (physical activity [PA], diet, human papillomavirus [HPV] vaccination, alcohol use, smoking, marijuana use, and unprotected sex) compared to age-matched peers and factors associated with those behaviors.

ELIGIBILITY CRITERIA

Four databases (PubMed, EMBASE, PsycINFO, and CINAHL) were searched for peer-reviewed primary studies published since 2000 including adolescents aged 11-20 years-old, who had completed cancer treatments. Studies reporting at least one behavior were included.

SAMPLE

Of 1979 articles reviewed, 27 studies reporting any of the following health behaviors were included: PA, diet, HPV vaccination, alcohol use, smoking, marijuana use, or unprotected sex.

RESULTS

Adolescent survivors of cancer engaged less in health risk behaviors (alcohol use, smoking, marijuana use, and unprotected sex) or health-promoting behaviors (PA, healthy diet, and HPV vaccination) compared to age-matched peers. Their health behaviors were associated with psychosocial factors including emotional discomfort (e.g., feeling depressed or nervous) and influence of others (family, friends, and healthcare providers).

CONCLUSIONS

Although health risk behaviors in adolescent survivors of cancer are not as prevalent as in their peers, the survivors' low engagement in health-promoting behaviors including PA, diet, and HPV vaccination is concerning.

IMPLICATIONS

More research is needed to develop and evaluate interventions to improve health-promoting behaviors in adolescent survivors of cancer by strengthening or facilitating psychosocial resources.

A Web-Based Intervention to Improve Health Literacy and Obesogenic Behaviors Among Adolescents: Protocol of a Randomized Pilot Feasibility Study for a Parallel Randomized Controlled Trial

BACKGROUND

Predictive theoretical models suggest that health knowledge works in conjunction with motivation and behavioral skills to influence adolescents' obesogenic behavior. However, most of the existing adolescent interventions target these variables in isolation. Furthermore, health literacy (HL), a precursor to health knowledge, is necessary for translating health knowledge into behavior and is negatively related to adolescents' obesity status. However, HL has not been included in obesity interventions targeting adolescents.

OBJECTIVE

This study aims to pilot the feasibility of a 2-armed web-based obesity prevention intervention in school settings and assess the preliminary effectiveness of adding an HL module to an obesity prevention intervention for adolescents.

METHODS

This web-based pilot feasibility study will take place in the Northeastern United States. Participants will be adolescents (aged 13-16 years) attending school, and recruitment will be conducted through flyers to parents and adolescents in participating classes or advisory groups at the school. The intervention includes 2 arms: an experimental arm that will receive an HL module and 3 obesity prevention modules and a comparison arm that will receive a vaping module and 3 obesity prevention modules. A blinded randomized procedure will be used to allocate classrooms and advisory groups to the experimental and comparison arms. The intervention will be fully web-based. Participants will complete measures of their HL and obesogenic behavior-related health knowledge, motivation, and behaviors at 3 time points (baseline, 1 month after the intervention, and 3 months after the intervention) via web-based surveys. The primary outcomes will be the measures of study feasibility (recruitment, retention, completion, and treatment fidelity rates). Secondary outcomes will be preliminary efficacy, as measured by logistic and linear regressions and calculation of effect sizes. Descriptive statistics will be calculated for all measures at each time point.

RESULTS

This study was approved by the City University of New York Institutional Review Board in August 2020. As of June 2022, the web-based intervention design is complete and ready for use. Recruitment, data collection, and intervention implementation are scheduled to begin in September 2022. These results are expected to be published in 2023.

CONCLUSIONS

This study's feasibility findings will inform changes to the intervention content and randomized controlled trial design. The study's efficacy findings will inform the sample size for the full-scale randomized controlled trial and the preliminary utility of the intervention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04252677; https://clinicaltrials.gov/ct2/show/NCT04252677.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/40191.

Cancer Risk Reduction Through Education of Adolescents: Development of a Tailored Cancer Risk-Reduction Educational Tool

Growing evidence links adolescent exposures to cancer risk later in life, particularly for common cancers like breast. The adolescent time period is also important for cancer risk reduction as many individual lifestyle behaviors are initiated including smoking and alcohol use. We developed a cancer risk-reduction educational tool tailored for adolescents that focused on five modifiable cancer risk factors. To contextualize risk factors in adolescents' social and physical environments, the intervention also focused on structural barriers to individual- and community-level change, with an emphasis on environmental justice or the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. The educational tool consisted of a 50-min module that included an introduction to cancer biology including genetic susceptibility and environmental interactions, cancer burden in the local community, and risk reduction strategies. The module also included an interactive activity in which adolescent students identify cancer risk factors and brainstorm strategies for risk reduction at both the individual and community level. We administered the module to 12 classes of over 280 high school and college students in New York City. Cancer risk reduction strategies identified by the students included family- or peer-level strategies such as team physical activity and community-level action including improving parks and taxing sugary foods. We developed a novel and interactive cancer risk-reduction education tool focused on multiple cancers that can be adopted by other communities and educational institutions.

Breakfast Habits and Associations with Fruit and Vegetable Intake, Physical Activity, Sedentary Time, and Screen Time among Swedish 13-14-Year-Old Girls and Boys

This study explored whether breakfast habits were associated with intake of fruits and vegetables, minutes in moderate-to-vigorous physical activity (MVPA), minutes spent sedentary, and screen time among adolescents. Cross-sectional data were collected among 13–14-year-old boys and girls (n = 1139). Breakfast habits and screen time were determined via questionnaire, fruit and vegetable intake were determined through dietary recall, and physical activity and sedentary time were determined via accelerometers. Multilevel mixed models and general estimation equation models were applied. Almost 40% of participants skipped breakfast at least one day of the week. Participants with irregular breakfast habits on weekdays had lower fruit and vegetable consumption by 26.7 g (95% CI = −49.3, −5.9) while irregular breakfast habits during the whole week were associated with higher levels of screen time (OR = 1.5, 95% CI = 1.1, 2.1) compared to regular breakfast habits. Girls with irregular breakfast habits on weekdays had 7.7 min more sedentary time (95% CI = 0.8, 15.7) than girls with regular breakfast habits, while the opposite was found in boys (β = −13.3, 95% CI = −25.3, −2.6)). No significant associations were found for MVPA. Regular breakfast habits should be encouraged, as they might contribute to a higher intake of fruit and vegetables and are associated with lower levels of screen time, although further studies are necessary to establish causation.

Parent Perceptions of Changes in Child Physical Activity During COVID-19 Stay-At-Home Orders

Purpose: The purpose of this study was to explore parent perceptions of changes in child physical activity during COVID-19 stay-at-home orders. Design: A cross-sectional study. Setting: The research team used social media, relevant organizations, and neighborhood groups to distribute the survey link in May and June of 2020. Subjects: A convenience sample of parents of children aged 5-12. Measures: Survey to assess parental perceptions of changes in children's physical activity before and during stay-at-home orders, and environmental and social barriers to physical activity. Analysis: Results were analyzed using descriptive statistics, bivariate comparisons, and multinomial-logistic regression models with covariates of environmental factors, social factors, and frequency of factors as barriers on association with perceived physical activity change. Results: Data from 245 parents were analyzed. A majority (63.7%) of parents reported a decrease in children's physical activity during stay-at-home orders. More parents indicated social barriers (e.g., lack of access to playmates) than environmental barriers (e.g., lack of access to neighborhood play spaces) to children's physical activity. In multivariate analyses, the odds of parents reporting decreased physical activity was greater for those reporting lack of playmates (OR = 4.72; 95% CI: 1.99-11.17) and lack of adult supervision (OR = 11.82; 95% CI: 2.48-56.28) as barriers. No environmental barriers were significantly associated with decreased children's physical activity. Conclusion: The unique aspects of the COVID-19 pandemic provide a natural experiment for developing social and environmental strategies to improve children's overall physical activity. Assessing parental perceptions is a way to inform these future efforts.

Cancer Prevention: Knowledge, Attitudes and Lifestyle Cancer-Related Behaviors among Adolescents in Italy

This study explores knowledge, attitudes and lifestyle behaviors related to cancer in a sample of adolescents. Data were collected through a self-administered questionnaire. 871 adolescents agreed to participate, with a response rate of 96.8%. Only 26.1% had a good level of knowledge on most risk factors for cancer. Adolescents with both parents employed, with a personal, familiar or friend history of cancer or having received information about cancer prevention from a physician, were more likely to have good knowledge about the risk factors for cancer. In total, 41% of participants declared that they consumed alcohol and 25.3% declared they were current smokers, 19.2% consumed fruits or vegetables more than once a day and 75.2% reported poor physical activity. Older adolescents, with a personal, familiar or friend history of cancer, not having one parent in the healthcare sector or not physically active were significantly more likely to be current smokers, whereas physical activity was significantly more likely in adolescents who had been informed by physicians on cancer prevention, and had one parent in the healthcare sector. This study highlights a need for improved education of adolescents about cancer prevention and lifestyle cancer-related behaviors.

The association between caesarean section delivery and later life obesity in 21-24 year olds in an Urban South African birth cohort

BACKGROUND

Obesity is an important public health problem and rates have reached epidemic proportions in many countries. Studies have explored the association between infants delivered by caesarean section and their later life risk of obesity, in many countries outside Africa. As a result of the increasing caesarean section and obesity rates in South Africa, we investigated the association in this country.

METHODS

This was a retrospective analysis of data that were collected from a prospective South African birth cohort (Birth to Twenty Plus), established in 1990. A total of 889 young adults aged 21-24 years were included in the analysis. Poisson regression models were fitted to assess the association between mode of delivery and early adulthood obesity.

RESULTS

Of the 889 young adults, 106 (11.9%) were obese while 72 (8.1%) were delivered by caesarean section; of which 14 (19.4%) were obese. Caesarean section delivery was significantly associated with obesity in young adults after adjusting for potential confounders like young adults' sex and birth weight, mothers' parity, and education (incidence rate ratio 1.64, 95% CI 1.01-2.68, p = 0.045).

CONCLUSION

The association of caesarean section with early adulthood obesity should be interpreted with caution because data on certain key confounding factors such as mothers' pre-pregnancy body mass index and gestational diabetes were not available. Further research from Africa, with larger sample sizes and databases with useful linking of maternal and infant data, should be conducted.

Predicting Hawaiian Youth's Physical Activity and Fruit and Vegetable Consumption Behaviors: A 10-Year Cohort Study

Background: Health behaviors in childhood and adolescence are implicated in health behaviors and chronic disease risk in adulthood for the majority of the US population. However, little is known about these relationships in Hawaiian youth. This study investigated the extent to which childhood physical activity (PA) and fruit and vegetable consumption behaviors predicted later behaviors across a 10-year period in Hawaiian youth. Methods: Three cohorts of fourth- to sixth-grade students who participated in an elementary after-school program (Fun 5) provided baseline data (Y1-data collected between 2003 and 2007), 5-year (Y5-data collected between 2008 and 2012), and 10-year (Y10-data collected between 2013 and 2017) follow-up surveys. Demographic, PA, and fruit and vegetable consumption measures were completed at all 3 time points. Bivariate and multiple regressions were computed in 2018. Results: Y1 and Y5 behavior predicted PA in young adulthood. For fruit and vegetable consumption, Y1 behavior predicted Y5 behavior but not Y10 behavior, and Y5 behavior predicted Y10 behaviors. Conclusions: Similar to mainland US youth, it is important to address PA and nutrition early in the life span for Hawaiian youth to increase long-term preventive health behaviors and reduce long-term chronic disease risk.

Cancer genetic health communication in families tested for hereditary breast/ovarian cancer risk: a qualitative investigation of impact on children's genetic health literacy and psychosocial adjustment

Children's literacy about the genetics of late-onset hereditary breast/ovarian cancer (HBOC) often develops through conversations with parents about BRCA gene testing and adults' cancer diagnoses. These conversations may promote early understanding of HBOC, but the long-term impact on children's psychosocial adjustment remains unclear. We investigated cancer genetic health communication in BRCA-tested families to consider benefits, risks, and moderating influences on children's understanding and well-being. Adolescent and young adult children (ages 12-24) of mothers who underwent BRCA testing 1+ years previously completed qualitative interviews that were transcribed, coded (intercoder K ≥ .70), and content-analyzed (N = 34). Children readily recalled conversations about BRCA testing and HBOC (100%) that they considered important (94%), but implications for children were ambiguous and obfuscated their concerns. Psychosocial impacts were muted, multifaceted, and displayed a range of favorable (82%), neutral (71%), and unfavorable (59%) response-frequently co-occurring within the same child over different aspects (e.g., medical, concern for self and others). Children verbalized active (50%) and avoidant (38%) coping strategies: about 1:5 endorsed transient thoughts about vulnerability to HBOC, 1:3 had not further considered it, and all reported specific actions they had or would undertake to remain healthy (e.g., diet/exercise). A majority (94%) of children had or would consider genetic testing for themselves, usually later in life (59%). Long-term outcomes highlighted benefits (awareness of HBOC, psychological hardiness, healthier lifestyle behaviors), as well as some psychosocial concerns that could be managed through interventions promoting genetic health literacy.

Adolescent Behavioral Cancer Prevention in the United States: Creating a Composite Variable and Ranking States' Performance

Preventive behaviors established during adolescence can reduce cancer throughout the life span. Understanding the combinations of multiple behaviors, and how these behaviors vary across states, is important for identifying where additional interventions are needed. Using data on 2011-2015 vaccination, energy balance, and substance use from national surveys, we created state-level composite scores for adolescent cancer prevention. Hierarchical Bayesian linear mixed models were used to predict estimates for states with no data on select behaviors. We used a Monte Carlo procedure with 100,000 simulations to generate states' ranks and 95% confidence intervals. Across states, hepatitis B vaccination was 84.3% to 97.1%, and human papillomavirus vaccination was 41.8% to 78.0% for girls and 19.0% to 59.3% for boys. For energy balance, 20.2% to 34.6% of adolescents met guidelines for physical activity, 4.1% to 15.8% for fruit and vegetable consumption, and 66.4% to 82.0% for healthy weight. For substance use, 82.5% to 93.5% reported abstaining from binge alcohol use, 84.3% to 95.4% from cigarette smoking, and 62.9% to 92.8% from marijuana use. (1) Rhode Island, (2) Colorado, (4) Hawaii and New Hampshire (tied), and (5) Vermont performed the best for adolescent cancer prevention, and (47) Missouri, (48) Arkansas, Mississippi, and South Carolina (tied), and (51) Kentucky performed the worst. However, 95% CIs around ranks often overlapped, indicating lack of statistical differences. Adolescent cancer prevention behaviors clustered into a composite index. States varied on their performance on this index, especially for states at the high and low extremes, but most states did not differ statistically. These findings can inform decision makers about where and how to intervene to improve cancer prevention among adolescents.

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.

Dietary habits in adolescence and midlife and risk of breast cancer in older women

Recent studies indicate that lifestyle factors in early life affect breast cancer risk. We therefore explored the association of high consumption of meat, milk, and whole grain products in adolescence and midlife, on breast cancer risk. We used data from the population based AGES-Reykjavik cohort (2002–2006), where 3,326 women with a mean age of 77 years (SD 6.0) participated. For food items and principal component derived dietary patterns we used Cox proportional models to calculate multivariate hazard ratios (HR) with 95% confidence intervals (95% CI). During a mean follow-up of 8.8 years, 97 women were diagnosed with breast cancer. For both adolescence and midlife, daily consumption of rye bread was positively associated with breast cancer (HR 1.7, 95% CI 1.1–2.6 and HR 1.8, 95% CI 1.1–2.9, respectively). In contrast, persistent high consumption of oatmeal was negatively associated with breast cancer (0.4, 95% CI 0.2–0.9). No association was found for other food items or dietary patterns that included rye bread. High rye bread consumption in adolescence and midlife may increase risk of late-life breast cancer whilst persistent consumption of oatmeal may reduce the risk.

Introduction to the Special Issue on Adolescent and Young Adult Health: Why We Care, How Far We Have Come, and Where We Are Going

This special issue on adolescent and young adult (AYA) health comprises 15 original articles. The special issue recognizes the importance of AYA-focused research, highlights unique issues across the AYA period, and showcases cutting-edge research focused on AYAs. We describe the rationale for focusing on the AYA population, themes of the special issue, and future directions.

Aerobic Exercise Training Attenuates Tumor Growth and Reduces Insulin Secretion in Walker 256 Tumor-Bearing Rats

Aerobic exercise training can improve insulin sensitivity in many tissues; however, the relationship among exercise, insulin, and cancer cell growth is unclear. We tested the hypothesis that aerobic exercise training begun during adolescence can attenuate Walker 256 tumor growth in adult rats and alter insulin secretion. Thirty-day-old male Wistar rats engaged in treadmill running for 8 weeks, 3 days/week, 44 min/day, at 55-65% VO2max until they were 90 days old (TC, Trained Control). An equivalently aged group was kept inactive during the same period (SC, Sedentary Control). Then, half the animals of the SC and TC groups were reserved as the control condition and the other half were inoculated with Walker 256 cancer cells, yielding two additional groups (Sedentary Walker and Trained Walker). Zero mortalities were observed in tumor-bearing rats. Body weight (BW), food intake, plasma glucose, insulin levels, and peripheral insulin sensitivity were analyzed before and after tumor cell inoculation. We also evaluated tumor growth, metastasis and cachexia. Isolated pancreatic islets secretory activity was analyzed. In addition, we evaluated mechanic sensibility. Our results showed improved physical performance according to the final workload and VO2max and reduced BW in trained rats at the end of the running protocol. Chronic adaptation to the aerobic exercise training decreased tumor weight, cachexia and metastasis and were associated with low glucose and insulin levels and high insulin sensitivity before and after tumor cell inoculation. Aerobic exercise started at young age also reduced pancreatic islet insulin content and insulin secretion in response to a glucose stimulus, without impairing islet morphology in trained rats. Walker 256 tumor-bearing sedentary rats also presented reduced pancreatic islet insulin content, without changing insulin secretion through isolated pancreatic islets. The mechanical sensitivity test indicated that aerobic exercise training did not cause injury or trigger inflammatory processes prior to tumor cell inoculation. Taken together, the current study suggests that aerobic exercise training applied during adolescence may mitigate tumor growth and related disorders in Walker 256 tumor-bearing adult rats. Improved insulin sensibility, lower glucose and insulin levels and/or reduced insulin secretion stimulated by glucose may be implicated in this tumor attenuation.

Life course evolution of body size and breast cancer survival in the E3N cohort

Although adult obesity has been associated with poor breast cancer survival, data on adiposity at different periods in life and its lifelong evolution are scarce. Our aims were to assess the associations between breast cancer survival and body size during childhood, puberty and early adulthood and body size trajectories from childhood to adulthood. Self-assessed body size at age 8, at puberty, at age 20-25 and at age 35-40 and trajectories of body size of 4,662 breast cancer survivors from the prospective E3N cohort were studied in relation to risk of death from any cause, death from breast cancer and second invasive cancer event using multivariate Cox regression models. Four trajectories of body size were identified (T1 "moderate increase," T2 "stable/low increase," T3 "increase at puberty" and T4 "constantly high"). Compared with stable body size, an increase in body size during adult life was associated with an increased risk of death from any cause (HR T1 vs. T2 = 1.27; 95% CI = 1.01-1.60) and an increased risk of second invasive cancer event (HR T1 vs. T2 = 1.25; 95% CI = 1.06-1.47). Silhouettes at various ages were not associated with survival. Our results suggest that the evolution of body size from childhood to adulthood has a long-term influence on breast cancer survival. Although these results need to be confirmed, this work sheds light on the need to combine lifelong approaches to current BMI to better identify breast cancer survivors who are at higher risk of recurrence or second primary cancer, or of death.

Test-Retest Reproducibility of Adult-Reported High School Diet Varies among Racially and Ethnically Diverse US Men and Women

Background

Adolescent diet is thought to play an important role in future chronic disease risk. However, few studies have examined the reproducibility of adult-reported adolescent diet, and evidence for possible differences in reproducibility by demographic characteristics is limited.

Objective

We assessed the ability of adults to consistently report past high school diet over a 1-y period and examined differences in reproducibility by selected demographic characteristics.

Methods

By using age-adjusted partial Spearman (ρ) or Pearson (r) correlations, we assessed 1-y reproducibility for 33 line items, 20 food groups, and 2 dietary patterns of high school diet reported in adulthood via a questionnaire completed by 742 participants in the Cancer Prevention Study 3 (CPS-3) Diet Substudy.

Results

Participants' median age was 53 y (range: 31-70 y), 65.2% were women, 59.8% were non-Hispanic white, 24.8% were non-Hispanic black, and 15.4% were Hispanic. The mean Spearman correlation assessing reproducibility across the 33 line items was 0.60 and ranged from 0.44 to 0.72, with no differences in mean correlations by age, sex, race/ethnicity, education, or body mass index (BMI). Reproducibility was similar across food groups (ρ = 0.62; range: 0.44-0.68), with differences by sex, ethnicity, age, or BMI observed for some food groups (e.g., sugar-sweetened beverages). Pearson correlations for the reproducibility of 2 major eating patterns, "fast food" and "whole food," were 0.73 and 0.72, respectively.

Conclusion

These results show good 1-y reproducibility of assessed high school diet, as reported from memory in adulthood, by line item, food group, and dietary pattern, with noted differences by demographic characteristics.

Mammographic non-dense area and breast cancer risk in postmenopausal women: a causal inference approach in a case-control study

PURPOSE

The association between high mammographic density (MD) and elevated breast cancer risk is well established. However, the role of absolute non-dense area remains unclear. We estimated the effect of the mammographic non-dense area and other density parameters on the risk of breast cancer.

METHODS

This study utilizes data from a population-based case-control study conducted in Greater Vancouver, British Columbia, with 477 female postmenopausal breast cancer cases and 588 female postmenopausal controls. MD measures were determined from digitized screening mammograms using computer-assisted software (Cumulus). Marginal odds ratios were estimated by inverse-probability weighting using a causal diagram for confounder selection. Akaike information criteria and receiver operating characteristic curves were used to assess the goodness of fit and predictive power of unconditional logistic models containing MD parameters.

RESULTS

The risk of breast cancer is 60% lower for the highest quartile compared to the lowest quartile of mammographic non-dense area (marginal OR 0.40, 95% CI 0.26-0.61, p-trend < 0.001). The cancer risk almost doubles for the highest quartile compared to the lowest quartile of dense area (marginal OR 1.81, 95% CI 1.19-2.43, p-trend < 0.001). For the highest quartile of percent density, breast cancer risk was more than three times higher than for the lowest quartile (marginal OR 3.15, 95% CI 1.90-4.40, p-trend < 0.001). No difference was seen in predictive accuracy between models using percent density alone, dense area alone, or non-dense area plus dense area.

CONCLUSIONS

In this study, non-dense area is an independent risk factor after adjustment for dense area and other covariates, inversely related with the risk of breast cancer. However, non-dense area does not improve prediction over that offered by percent density or dense area alone.

Comparing percentages and ranks of adolescent weight-related outcomes among U.S. states: Implications for intervention development

Understanding statistical differences in states' percentages and ranks of adolescents meeting health behavior guidelines can guide policymaking. Data came from 531,777 adolescents (grades 9-12) who completed the Youth Risk Behavior Surveillance System survey in 2011, 2013, or 2015. We measured the percentage of adolescents in each state that met guidelines for physical activity, fruit and vegetable (F&V) consumption, and healthy weight status. Then we ranked states and calculated the ranks' 95% CI's using a Monte Carlo method with 100,000 simulations. We repeated these analyses stratified by sex (female or male) or race/ethnicity (non-Hispanic white, non-Hispanic black, Hispanic/Latino, or other). Pearson's and Spearman's correlation coefficients examined consistency in the percentages and ranks (respectively) across behaviors and subgroups. Meeting the physical activity and F&V consumption guidelines was relatively rare among adolescents (25.8% [95% CI=25.2%-26.4%] and 8.0% [95% CI=7.6%-8.3%], respectively), while meeting the healthy weight guideline was common (71.5% [95% CI=70.7%-72.3%]). At the state level, percentages of adolescents meeting these guidelines were statistically similar; states' ranks had wide CI's, resulting in considerable overlap (i.e., statistical equivalence). For each behavior, states' percentages and ranks were moderately to highly correlated across adolescent subgroups (Pearson's r=0.33-0.96; Spearman's r=0.42-0.96), but across behaviors, only F&V consumption and healthy weight were correlated (Pearson's r=0.34; Spearman's r=0.37). Adolescents in all states could benefit from initiatives to support cancer prevention behaviors, especially physical activity and F&V consumption. Programs in states that ranked highly on all assessed health behaviors could be adapted for dissemination in lower-performing states.

A systematic review of grandparents' influence on grandchildren's cancer risk factors

Many lifestyle patterns are established when children are young. Research has focused on the potential role of parents as a risk factor for non communicable disease in children, but there is limited investigation of the role of other caregivers, such as grandparents. The aim of this review was to identify and synthesise evidence for any influence grandparents' care practices may have on their grandchildren's long term cancer risk factors. A systematic review was carried out with searches across four databases (MEDLINE, Embase, Web of Science, PsycINFO) as well as searches of reference lists and citing articles, and Google Scholar. Search terms were based on six areas of risk that family care could potentially influence-weight, diet, physical activity, tobacco, alcohol and sun exposure. All study designs were included, as were studies that provided an indication of the interaction of grandparents with their grandchildren. Studies were excluded if grandparents were primary caregivers and if children had serious health conditions. Study quality was assessed using National Institute for Health and Care Excellence checklists. Grandparent impact was categorised as beneficial, adverse, mixed or as having no impact. Due to study heterogeneity a meta-analysis was not possible. Qualitative studies underwent a thematic synthesis of their results. Results from all included studies indicated that there was a sufficient evidence base for weight, diet, physical activity and tobacco studies to draw conclusions about grandparents' influence. One study examined alcohol and no studies examined sun exposure. Evidence indicated that, overall, grandparents had an adverse impact on their grandchildren's cancer risk factors. The theoretical work in the included studies was limited. Theoretically underpinned interventions designed to reduce these risk factors must consider grandparents' role, as well as parents', and be evaluated robustly to inform the evidence base further.

Pubertal growth and adult height in relation to breast cancer risk in African American women

Adult height has been positively associated with breast cancer risk. The timing of pubertal growth-as measured by age at menarche and age at attained height-may also influence risk. We evaluated associations of adult height, age at attained height, and age at menarche with incidence of invasive breast cancer in 55,687 African American women in the prospective Black Women's Health Study. Over 20 years, 1,826 invasive breast cancers [1,015 estrogen receptor (ER) positive; 542 ER negative] accrued. We used multivariable Cox proportional hazards regression to estimate hazards ratios (HRs) and 95% confidence intervals (CIs) for associations with breast cancer overall and by ER status, mutually adjusted for the three factors of interest. Adult height was associated with increased risk of ER+ breast cancer (HR for ≥70 inches vs ≤63 inches: 1.44; 95% CI: 1.09, 1.89) but not ER- (corresponding HR: 1.16; 95% CI: 0.78, 1.71) (p heterogeneity = 0.34). HRs for attained height before age 13 versus age >17 were 1.30 (95% CI: 0.96, 1.76) for ER+ and 1.25 (95% CI: 0.80, 1.96) for ER- breast cancer. Results for age at menarche (≤11 vs ≥14 years) were similar for ER+ and ER- breast cancer (HR for breast cancer overall: 1.30; 95% CI: 1.12, 1.50). We confirmed height as a strong risk factor for ER+ breast cancer in African American women and identified early age at attained height as a risk factor for both ER+ and ER- breast cancer, albeit without statistical significance of the latter associations. While adult height and timing of pubertal growth are inter-related, our findings suggest that they may be independent risk factors for breast cancer.

Adolescent exercise in association with mortality from all causes, cardiovascular disease, and cancer among middle-aged and older Chinese women

BACKGROUND

Little is known regarding the role of early-life exercise, a potentially modifiable factor, in long-term adult morbidity and mortality. We utilized the Shanghai Women's Health Study (SWHS) to investigate adolescent exercise in association with cancer, cardiovascular disease (CVD), and all-cause mortality among middle-aged and older women.

METHODS

The SWHS is a prospective cohort of 74,941 Chinese women ages 40 to 70 years recruited from 1996 to 2000. In-person interviews at enrollment assessed adolescent and adult exercise history, medical and reproductive history, and other lifestyle and socioeconomic (SES) factors. Mortality follow-up occurs via annual linkage to the Shanghai Vital Statistics Registry. Adjusted hazard ratios (HR) and 95% confidence intervals (CI) were derived from Cox regression models.

RESULTS

Adjusting for birth year and other adolescent factors, adolescent exercise was associated with reduced risk of cancer, CVD, and total mortality [HRs (95% CI), 0.83 (0.72-0.95), 0.83 (0.70-0.98), and 0.78 (0.71-0.85), respectively for ≤1.33 hours (h)/week, and 0.83 (0.74-0.93), 0.62 (0.53-0.72), and 0.71 (0.66-0.77), respectively for >1.33 h/week (reference = none)]. Results were attenuated after adjustment for adult SES and lifestyle factors. Participation in sports teams was inversely associated with cancer mortality [HR (95% CI), 0.86 (0.76-0.97)]. Joint adolescent and adult exercise was associated with reduced risk of all-cause, CVD, and cancer mortality [HRs (95% CIs), 0.80 (0.72-0.89), 0.83 (0.69-1.00), and 0.87 (0.74-1.01), respectively], adjusting for adult/adolescent factors, and adolescence exercise only was inversely associated with cancer mortality [HR (95% CI), 0.84 (0.71-0.98)].

CONCLUSIONS

Adolescent exercise participation, independent of adult exercise, was associated with reduced risk of cancer, CVD, and all-cause mortality.

IMPACT

Results support promotion of exercise in adolescence to reduce mortality in later life.

Perinatal and childhood factors and risk of breast cancer subtypes in adulthood

BACKGROUND

Accumulated exposure to hormones and growth factors during early life may influence the future risk of breast cancer (BC). This study examines the influence of childhood-related, socio-demographic and anthropometric variables on BC risk, overall and by specific pathologic subtypes.

METHODS

This is a case-control study where 1539 histologically-confirmed BC cases (23-85 years) and 1621 population controls, frequency matched by age, were recruited in 10 Spanish provinces. Perinatal and childhood-related characteristics were directly surveyed by trained staff. The association with BC risk, globally and according to menopausal status and pathologic subtypes, was evaluated using logistic and multinomial regression models, adjusting for tumor specific risk factors.

RESULTS

Birth characteristics were not related with BC risk. However, women with high socioeconomic level at birth presented a decreased BC risk (OR=0.45; 95% CI=0.29-0.70), while those whose mothers were aged over 39 years at their birth showed an almost significant excess risk of hormone receptor positive tumors (HR+) (OR=1.35; 95% CI=0.99-1.84). Women who were taller than their girl mates before puberty showed increased postmenopausal BC risk (OR=1.26; 95% CI=1.03-1.54) and increased HR+ BC risk (OR=1.26; 95% CI=1.04-1.52). Regarding prepubertal weight, while those women who were thinner than average showed higher postmenopausal BC risk (OR=1.46; 95% CI=1.20-1.78), associated with HR+ tumors (OR=1.34; 95% CI=1.12-1.61) and with triple negative tumors (OR=1.56; 95% CI=1.03-2.35), those who were heavier than average presented lower premenopausal BC risk (OR=0.64; 95% CI=0.46-0.90) and lower risk of epidermal growth factor receptor positive tumors (OR=0.61; 95% CI=0.40-0.93).

CONCLUSION

These data reflect the importance of hormones and growth factors in the early stages of life, when the mammary gland is in development and therefore more vulnerable to proliferative stimuli.

Childhood Exposures and Risk of Malignancy in Adulthood

Pediatricians have significant roles in preventive health care, and understanding how various exposures during childhood can have long-lasting effects on cancer risk is critical in promoting future health. With the exception of rare genetic syndromes conferring increased cancer susceptibility, most cancers are considered idiopathic and may be influenced by modifiable exposures and risks. This review aims to serve as a brief overview of a subset of known exposures during childhood that have been associated with an increased risk of malignancy in adulthood, including the effects of radiation, chemotherapy, pesticides, nutrition, puberty, and infection.

Racial and ethnic disparities in the impact of obesity on breast cancer risk and survival: a global perspective

Obesity is a global concern, affecting both developed and developing countries. Although there are large variations in obesity and breast cancer rates worldwide and across racial/ethnic groups, most studies evaluating the impact of obesity on breast cancer risk and survival have been conducted in non-Hispanic white women in the United States or Europe. Given the known racial/ethnic differences in tumor hormone receptor subtype distribution, obesity prevalence, and risk factor profiles, we reviewed published data for women of African, Hispanic, and Asian ancestry in the United States and their countries of origin. Although the data are limited, current evidence suggests a stronger adverse effect of obesity on breast cancer risk and survival in women of Asian ancestry. For African Americans and Hispanics, the strength of the associations appears to be more comparable to that of non-Hispanic whites, particularly when accounting for subtype and menopausal status. Central obesity seems to have a stronger impact in African-American women than general adiposity as measured by body mass index. International data from countries undergoing economic transition offer a unique opportunity to evaluate the impact of rapid weight gain on breast cancer. Such studies should take into account genetic ancestry, which may help elucidate differences in associations between ethnically admixed populations. Overall, additional large studies that use a variety of adiposity measures are needed, because the current evidence is based on few studies, most with limited statistical power. Future investigations of obesity biomarkers will be useful to understand possible racial/ethnic biological differences underlying the complex association between obesity and breast cancer development and progression.

Early motor skill competence as a mediator of child and adult physical activity

OBJECTIVE

In order to effectively promote physical activity (PA) during childhood, and across the lifespan, a better understanding of the role of early motor skill development on child and adult PA is needed.

METHODS

Here, we propose a conceptual model delineating the hypothesized influence of motor skill development on child and adult PA, while providing an overview of the current empirical research related to this model.

RESULTS

There is consistent and emerging evidence showing that adequate motor skill competence, particularly locomotor and gross motor skills, is associated with increased PA levels during the preschool, child, and adolescent years, with early motor skill development also influencing enjoyment of PA as well as long-term PA and motor skill performance. The physical education setting appears to be a well-suited environment for motor skill development.

CONCLUSION

Employing appropriate strategies to target motor skill development across the childhood years is of paramount interest in helping shape children's PA behavior, their experiences related to PA, as well as maintain their PA.

Implications of Facilitators and Barriers to Implementing Fuel Up to Play 60

OBJECTIVES

The primary purpose of this study was to identify barriers and facilitators of Fuel Up to Play 60 (FUTP60) program implementation.

METHODS

This was an observational study occurring over 20 months in 4 schools in metropolitan Denver, Colorado. Key informant interviews and FUTP60 surveys examined the barriers and facilitators of program implementation and utilization of other health-promotion programs.

RESULTS

Program advisors stated that the adaptability of FUTP60 eased program implementation in schools, helped schools to meet wellness policy goals, and that the program message resonated with students.

CONCLUSIONS

FUTP60's adaptability to a school's needs, its simple messaging and student-centric model were major facilitators of program implementation and should be considered when implementing other school-based programs.

Maternal weight gain in pregnancy and risk of obesity among offspring: a systematic review

OBJECTIVES

To systematically review the evidence from prospective and retrospective cohort studies on the association between gestational weight gain (GWG) and offspring's body weight.

METHODS

Electronic databases PubMed, Web of Science, CINAHL, and Academic Search Premiere were searched from inception through March 18, 2013. Included studies (n = 23) were English articles that examined the independent associations of GWG with body mass index (BMI) and/or overweight status in the offspring aged 2 to 18.9 years. Two authors independently extracted the data and assessed methodological quality of the included studies.

RESULTS

Evidence from cohort studies supports that total GWG and exceeding the Institute of Medicine maternal weight gain recommendation were associated with higher BMI z-score and elevated risk of overweight or obesity in offspring. The evidence of high rate of GWG during early- and mid-pregnancy is suggestive. Additionally, the evidence on inadequate GWG and net GWG in relation to body weight outcomes in offspring is insufficient to draw conclusions.

CONCLUSIONS

These findings suggest that GWG is a potential risk factor for childhood obesity. However, findings should be interpreted with caution due to measurement issues of GWG and potential confounding effects of shared familial characteristics (i.e., genetics and maternal and child's lifestyle factors).

Overweight in early adulthood, adult weight change, and risk of type 2 diabetes, cardiovascular diseases, and certain cancers in men: a cohort study

The relative importance of overweight after childhood and excess weight gain during adulthood remains unclear. In 39,909 male participants of the Health Professionals Follow-Up Study who were 40-75 years of age in 1986 and were followed until 2008, we documented 8,755 incident cases of obesity-related chronic diseases (type 2 diabetes mellitus, cardiovascular diseases, and colorectal, renal, pancreatic, and esophageal cancers). We calculated composite and cause-specific hazard ratios using a model that included body mass index (BMI; weight (kg)/height (m)(2)) at 21 years of age, weight change since age 21 years, smoking, alcohol consumption, and family histories of myocardial infarction, colon cancer, and diabetes. Compared with a BMI at 21 years of 18.5-22.9, the composite hazard ratio for a BMI of 23-24.9 was 1.22 (95% confidence interval (CI): 1.16, 1.29), that for a BMI of 25.0-27.4 was 1.57 (95% CI: 1.48, 1.67), that for a BMI of 27.5-29.9 was 2.40 (95% CI: 2.17, 2.65), and that for a BMI ≥30.0 was 3.15 (95% CI: 2.76, 3.60). The composite hazard ratios for adult weight gain compared with a stable weight were 1.12 (95% CI: 1.03, 1.22) for a gain of 2.5-4.9 kg, 1.41 (95% CI: 1.31, 1.52) for a gain of 5-9.9 kg, 1.72 (95% CI: 1.59, 1.86) for a gain of 10-14.9 kg, and 2.45 (95% CI: 2.27, 2.63) for a gain ≥15 kg. Adiposity in early adulthood and adult weight gain were both associated with marked increases in the risk of major chronic diseases in middle-aged and older men, and these associations were already apparent at modest levels of overweight and weight gain.

Breast cancer risk accumulation starts early: prevention must also

Nearly one in four breast cancers is diagnosed before the age of 50, and many early-stage premalignant lesions are present but not yet diagnosed. Therefore, we review evidence to support the strategy that breast cancer prevention efforts must begin early in life. This study follows the literature review methods and format. Exposures during childhood and adolescence affect a woman's long-term risk of breast cancer, but have received far less research attention than exposures that occur later in life. Breast tissue undergoes rapid cellular proliferation between menarche and first full-term pregnancy, and risk accumulates rapidly until the terminal differentiation that accompanies first pregnancy. Evidence on childhood diet and growth in height, and adolescent alcohol intake, among other adolescent factors is related to breast cancer risk and risk of premalignant proliferative benign lesions. Breast cancer prevention efforts will have the greatest effect when initiated at an early age and continued over a lifetime. Gaps in knowledge are identified and deserve increase attention to inform prevention.

Associations of mammographic dense and nondense areas and body mass index with risk of breast cancer

Mammographic density measurements are associated with risk of breast cancer. Few studies have investigated the concurrent associations of mammographic dense and nondense areas, body mass index (weight (kg)/height (m)(2)), and ages at mammogram and diagnosis with breast cancer risk. We conducted a matched, case-control study nested within the Melbourne Collaborative Cohort Study (cohort recruitment in 1990-1994 and follow-up until 2007) to estimate the associations between these factors and breast cancer risk under alternative causal models. Mammographic dense area was positively associated with risk, and the strength of this association was only slightly influenced by the choice of the causal model (relative risk per 1 standard deviation = 1.50, 95% confidence interval: 1.32, 1.70). Mammographic nondense area was inversely associated with risk under the assumption that fat in the body and fat in the breast cause breast cancer through independent mechanisms (relative risk per 1 standard deviation = 0.75, 95% confidence interval: 0.65, 0.86), whereas it was not associated with risk under the assumption that they are both proxies of adiposity. Knowledge about the biological mechanisms regulating the role played by mammographic nondense area and body fat on breast cancer risk is essential to better estimate their impacts on individual risk.

Association between childhood overweight measures and adulthood knee pain, stiffness and dysfunction: a 25-year cohort study

OBJECTIVE

To describe the associations between overweight measures in childhood and knee pain, stiffness and dysfunction among adults 25 years later.

METHODS

Subjects broadly representative of the Australian population (n=449, aged 31-41 years, female 48%) were selected from the Australian Schools Health and Fitness Survey of 1985. Height, weight and knee injury were recorded and knee pain was assessed using the Western Ontario and McMaster Universities osteoarthritis index (WOMAC). Childhood height, weight and knee injury had been measured according to standard protocols 25 years earlier and body mass index (BMI) and percentage overweight were calculated.

RESULTS

The prevalence of knee pain was 34% and overweight in childhood and adulthood was 7% and 48%, respectively. Overall, there were no significant associations between childhood overweight measures and total WOMAC knee pain, stiffness and dysfunction scores in adulthood. However, in men, overweight in childhood was associated with adulthood WOMAC pain (relative risk (RR) 1.72, 95% CI 1.11 to 2.69) and childhood weight and BMI were associated with WOMAC stiffness and dysfunction. Childhood weight, BMI and overweight were all associated with the presence of adulthood walking knee pain in men and the whole sample. Most of these associations were independent of adult overweight measures. Subjects who were overweight in both childhood and adult life had a significant increase in the risk and prevalence of adulthood walking pain (RR=2.42, 95% CI 1.06 to 5.53).

CONCLUSIONS

Childhood overweight measures were significantly associated with adulthood knee mechanical joint pain, stiffness and dysfunction among men, independent of adult overweight, suggesting that childhood overweight may lead to later knee symptoms in men.

Childhood height and birth weight in relation to future prostate cancer risk: a cohort study based on the copenhagen school health records register

BACKGROUND

Adult height has been positively associated with prostate cancer risk. However, the exposure window of importance is currently unknown and assessments of height during earlier growth periods are scarce. In addition, the association between birth weight and prostate cancer remains undetermined. We assessed these relationships in a cohort of the Copenhagen School Health Records Register (CSHRR).

METHODS

The CSHRR comprises 372,636 school children. For boys born between the 1930s and 1969, birth weight and annual childhood heights-measured between ages 7 and 13 years-were analyzed in relation to prostate cancer risk. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI).

RESULTS

There were 125,211 males for analysis, 2,987 of who were subsequently diagnosed with prostate cancer during 2.57 million person-years of follow-up. Height z-score was significantly associated with prostate cancer risk at all ages (HRs, 1.13 to 1.14). Height at age 13 years was more important than height change (P = 0.024) and height at age 7 years (P = 0.024), when estimates from mutually adjusted models were compared. Adjustment of birth weight did not alter the estimates. Birth weight was not associated with prostate cancer risk.

CONCLUSIONS

The association between childhood height and prostate cancer risk was driven by height at age 13 years.

IMPACT

Our findings implicate late childhood, adolescence, and adulthood growth periods as containing the exposure window(s) of interest that underlies the association between height and prostate cancer. The causal factor may not be singular given the complexity of both human growth and carcinogenesis.

Body size in early life and breast cancer risk in African American and European American women

PURPOSE

There is growing evidence that body size in early life influences lifetime breast cancer risk, but little is known for African American (AA) women.

METHODS

We evaluated body size during childhood and young adulthood and breast cancer risk among 1,751 cases [979 AA and 772 European American (EA)] and 1,673 controls (958 AA and 715 EA) in the Women's Circle of Health Study. Odds ratio (OR) and 95 % confidence intervals (CI) were computed using logistic regression models while adjusting for potential covariates.

RESULTS

Among AA women, being shorter at 7-8 years compared to peers was associated with increased postmenopausal breast cancer risk (OR 1.68, 95 % CI 1.02-2.74), and being heavier at menarche with decreased postmenopausal breast cancer risk, although of borderline significance (OR 0.45, 95 % CI 0.20-1.02). For EA women, being shorter from childhood through adolescence, particularly at menarche, was associated with reduced premenopausal breast cancer risk (OR 0.55, 95 % CI 0.31-0.98). After excluding hormone replacement therapy users, an inverse association with postmenopausal breast cancer was found among EA women reporting to be heavier than their peers at menarche (OR 0.18, 95 % CI 0.04-0.79). The inverse relationship between BMI at age 20 and breast cancer risk was stronger and only statistically significant in EA women. No clear association with weight gain since age 20 was found.

CONCLUSIONS

Findings suggest that the impact of childhood height on breast cancer risk may differ for EA and AA women and confirm the inverse association previously reported in EA populations with adolescent body fatness, in AA women.

Invited commentary: are dietary intakes and other exposures in childhood and adolescence important for adult cancers?

In this issue of the Journal, Nimptsch et al. (Am J Epidemiol. 2013;178(2):172-183) report significant associations between female adolescents' poultry consumption in high school and subsequent reduced risk of colorectal adenomas in adulthood. Consumption of red meat or fish was not related to risk, but replacement with poultry reduced the risk of later adenomas. Most epidemiologic studies of adult diseases lack exposure data from the distant past. By focusing on a cancer precursor lesion and using a variety of methods to assess data quality, the investigators address concerns about the quality of distant recall. These findings add to the growing evidence that links childhood and adolescent lifestyle and environmental exposures with subsequent risk of cancers arising in adulthood. Highlights of the literature on this topic and methodological challenges are summarized. Future studies would benefit from incorporating measures of lifestyle, diet, environmental exposures, and other risk factors from early in life and from validation and other data quality checks of such measurements. Sources of historical data on children's and adolescents' exposures should be sought and evaluated in conjunction with subsequent exposures in relationship to adult-onset cancers.

Meta-analysis of green tea drinking and the prevalence of gynecological tumors in women

We performed a meta-analysis of the correlation between drinking green tea and the risk of female ovarian tumors. Related literature (2000-2010) was retrieved from PubMed, EMbase, CBMdisc, CNKI, and Wanfang databases. The relationship between the prevalence of ovarian cancer and drinking tea in cohort studies was explored. RevMan5.1.0 software was used for the meta-analysis. A total of 6 case control studies and cohort studies were included. A total of 9113 participants, 3842 cases, and 5271 control cases were included in our analysis. Our analysis indicates that drinking green tea can significantly decrease the risk of ovarian cancer (odds ratio = 0.81; 95% confidence interval = 0.73-0.89; P < .0001). Further research is needed to explore the relationship between drinking green tea and the risk of ovarian tumor in different groups of people and with different tea types and dosages.

Highlights from a workshop on opportunities for cancer prevention during preadolescence and adolescence

In an effort to explore opportunities for cancer prevention during preadolescence and adolescence, the Cancer Prevention Across the Lifespan workgroup within the Division of Cancer Prevention and Control at the Centers for Disease Control and Prevention (CDC) convened an informal panel of experts for a 2-day workshop August 9-10, 2011. In this report, we provide highlights from the workshop. A central theme of the workshop was that preadolescence and adolescence are times of unique susceptibility and vulnerability within the lifespan. Participants discussed the evidence linking exposures during adolescence (e.g., risky behaviors, chemicals, medical imaging procedures) and subsequent cancer risk during adulthood. Participants also discussed potential opportunities to intervene on risk factors for cancer at multiple levels during adolescence, the importance of more focused approaches to adequately address health disparities, and the ongoing need for transdisciplinary and translational prevention research. Future opportunities for the CDC include further leveraging surveillance data from sources such as the National Health and Nutrition Examination Survey, the Youth Risk Behavior Surveillance System, and the National Children's Study and continuing to build on collaborations with other federal agencies and with national, state, and local organizations. Many ideas and insights generated during the workshop will be put into action as CDC continues to explore opportunities for cancer prevention during youth and across the lifespan.

Preventing cancer: a community-based program for youths in public housing

PURPOSE

This article describes a feasibility study of a program that mentors boys aged 14-18 living in inner city public housing, engages them in a basketball league, and provides educational sessions on life skills and ways to resolve conflicts without violence. Such programs have the potential to engage adolescent males living in public housing in activities that reduce cancer-related behaviors and increase protective behaviors.

METHODS

We conducted a feasibility evaluation of the program, which included a survey of participants, interviews with coaches, and observations of games and practices.

RESULTS

Lifetime and previous-30-day substance use was common among participants, and many were exposed to and had experienced various forms of violence. Keeping youths active helps prevent their joining gangs and using drugs.

CONCLUSIONS

Youths from disadvantaged backgrounds are at a high risk for cancer because they are at greater risk for obesity and other adverse health-related conditions than are more affluent youths. Implementing and sustaining community programs for youths in public housing can reduce the effects of exposure to factors that put them at risk for cancer during adulthood: chronic poverty, lack of safe areas for recreation, easy access to alcohol and drugs, and exposure to violence. In addition, workshops to prevent substance use and violence and to teach leadership, sportsmanship, conflict resolution, and healthy youth development are needed for youths, coaches, and parents or guardians.

Turning disciplinary knowledge into solutions

Turning disciplinary knowledge about preadolescents' and adolescents' exposure to risk factors for cancer as adults into solutions for preventing such an outcome requires that investigators from a variety of backgrounds and disciplines come together to share knowledge. Optimally, these collaborations would occur across two dimensions: (1) transdisciplinary, from the molecular or cellular level (e.g., animal studies of endocrine disruption) to the societal level (e.g., economic studies related to state tobacco policies); and (2) translational, using basic research findings in clinical and other sciences to implement prevention programs and public policy. Only when collaboration is commonplace can the disparate groups of investigators working on cancer prevention during preadolescence and adolescence gain a holistic picture of the risk factors, inform one another's work, and learn what we need to know to devise successful interventions for preventing cancer. Working transdisciplinarily also helps to ensure that messages to health professionals, policymakers, the news media, and the public are consistent and coordinated. At present, those investigating preadolescent and adolescent risk for adult cancer disseminate their knowledge individually, thus missing the opportunity to synthesize knowledge, coordinate dissemination, and implement prevention programs. In this article, we distinguish multidisciplinary, interdisciplinary, and transdisciplinary approaches; argue for the benefits of a transdisciplinary approach to devising successful solutions; and explore how to achieve transdisciplinary functioning.

Differential DNA methylation patterns between high and low responders to a weight loss intervention in overweight or obese adolescents: the EVASYON study

In recent years, epigenetic markers emerged as a new tool to understand the influence of lifestyle factors on obesity phenotypes. Adolescence is considered an important epigenetic window over a human's lifetime. The objective of this work was to explore baseline changes in DNA methylation that could be associated with a better weight loss response after a multidisciplinary intervention program in Spanish obese or overweight adolescents. Overweight or obese adolescents (n=107) undergoing 10 wk of a multidisciplinary intervention for weight loss were assigned as high or low responders to the treatment. A methylation microarray was performed to search for baseline epigenetic differences between the 2 groups (12 subjects/group), and MALDI-TOF mass spectrometry was used to validate (n=107) relevant CpG sites and surrounding regions. After validation, 5 regions located in or near AQP9, DUSP22, HIPK3, TNNT1, and TNNI3 genes showed differential methylation levels between high and low responders to the multidisciplinary weight loss intervention. Moreover, a calculated methylation score was significantly associated with changes in weight, BMI-SDS, and body fat mass loss after the treatment. In summary, we have identified 5 DNA regions that are differentially methylated depending on weight loss response. These methylation changes may help to better understand the weight loss response in obese adolescents.

Serum lipid profiles and cancer risk in the context of obesity: four meta-analyses

The objective here was to summarize the evidence for, and quantify the link between, serum markers of lipid metabolism and risk of obesity-related cancers. PubMed and Embase were searched using predefined inclusion criteria to conduct meta-analyses on the association between serum levels of TG, TC, HDL, ApoA-I, and risk of 11 obesity-related cancers. Pooled relative risks (RRs) and 95% confidence intervals were estimated using random-effects analyses. 28 studies were included. Associations between abnormal lipid components and risk of obesity-related cancers when using clinical cutpoints (TC ≥ 6.50; TG ≥ 1.71; HDL ≤ 1.03; ApoA-I ≤ 1.05 mmol/L) were apparent in all models. RRs were 1.18 (95% CI: 1.08–1.29) for TC, 1.20 (1.07–1.35) for TG, 1.15 (1.01–1.32) for HDL, and 1.42 (1.17–1.74) for ApoA-I. High levels of TC and TG, as well as low levels of HDL and ApoA-I, were consistently associated with increased risk of obesity-related cancers. The modest RRs suggest serum lipids to be associated with the risk of cancer, but indicate it is likely that other markers of the metabolism and/or lifestyle factors may also be involved. Future intervention studies involving lifestyle modification would provide insight into the potential biological role of lipid metabolism in tumorigenesis.

Diet-induced metabolic change induces estrogen-independent allometric mammary growth

Lifetime breast cancer risk reflects an unresolved combination of early life factors including diet, body mass index, metabolic syndrome, obesity, and age at first menses. In parallel, the onset of allometric growth by the mammary glands around puberty is widely held to be estrogen (E)-dependent. Here we report that several physiological changes associated with metabolic syndrome in response to a diet supplemented with the trans-10, cis-12 isomer of conjugated linoleic acid lead to ovary-independent allometric growth of the mammary ducts. The E-independence of this diet-induced growth was highlighted by the fact that it occurred both in male mice and with pharmacological inhibition of either E receptor function or E biosynthesis. Reversal of the metabolic phenotype with the peroxisome proliferator-activated receptor-γ agonist rosiglitazone abrogated diet-induced mammary growth. A role for hyperinsulinemia and increased insulin-like growth factor-I receptor (IGF-IR) expression during mammary growth induced by the trans-10, cis-12 isomer of conjugated linoleic acid was confirmed by its reversal upon pharmacological inhibition of IGF-IR function. Diet-stimulated ductal growth also increased mammary tumorigenesis in ovariectomized polyomavirus middle T-antigen mice. Our data demonstrate that diet-induced metabolic dysregulation, independently of ovarian function, stimulates allometric growth within the mammary glands via an IGF-IR-dependent mechanism.

The maternal womb: a novel target for cancer prevention in the era of the obesity pandemic?

The dramatic rise in worldwide prevalence of obesity has necessitated the search for more efficacious antiobesity strategies to counter the increased cancer risks in overweight and obese individuals. The mechanistic pathways linking obesity status with adult chronic diseases such as cancer remain incompletely understood. A growing body of evidence suggests that novel approaches and interventional agents to disrupt the feed-forward cycle of maternal to offspring obesity transfer that is initiated in utero will be important for stemming both the obesity pandemic and the associated increase in cancer incidence. The convergence of multiple research areas including those encompassing the insulin and insulin-like growth factor systems, epigenetics, and stem cell biology is providing insights into the potential for cancer prevention in adult offspring previously exposed to the intrauterine environment of overweight/obese mothers. Here, we review the current state of this nascent research field, with a focus on three major cancers, namely breast, colorectal, and liver, and suggest some possible future directions to optimize its impact for the health of future generations.

Parenting practices as mediators of child physical activity and weight status

Understanding the environmental factors that influence children's physical activity is an important prerequisite before effective physical activity interventions can be developed and implemented. Parenting is one environmental factor that has been empirically shown to positively influence children's physical activity. However, in order to promote physical activity in children, a better understanding of how parents influence children's physical activity behavior is required. Previously, Birch and Davison developed a model depicting parental factors hypothesized to influence child dietary behaviors. We extended this model by identifying parental factors hypothesized to promote physical activity in children. This review focuses on the mediational role that parenting practices and behaviors play in influencing child mediators of physical activity behavior, and, ultimately, weight status. Priorities for future research are discussed.