Recreational Physical Activity and Leisure-Time Sitting in Relation to Postmenopausal Breast Cancer Risk

Recreational physical activity and breast cancer risk by menopausal status and tumor hormone receptor status: results from the Nurses' Health Studies

PURPOSE

Physical activity is associated with lower breast cancer risk, especially in postmenopausal women. Associations in premenopausal women are less well established.

METHODS

We evaluated recreational physical activity and breast cancer risk in the Nurses' Health Study (NHS) and NHSII (187,278 women; n = 12,785 breast cancers; follow-up: NHS = 1986-2016, NHSII = 1989-2017) by menopausal status and estrogen (ER) and progesterone (PR) receptor status. Physical activity was evaluated as updated cumulative average of metabolic equivalent of task (MET)-h/week. Cox proportional hazards models were used to estimate multivariable hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Recreational physical activity was inversely associated with breast cancer risk in pre- and postmenopausal women. Higher activity levels were associated with lower risk of ER+/PR + breast cancer in both pre- and postmenopausal women (e.g., total recreational activity, ≥ 27 vs < 3 MET-h/week, premenopausal HR = 0.83, 95%CI = (0.70-0.99), postmenopausal HR = 0.86 (0.78-0.95); pheterogeneity = 0.97). Results were attenuated with adjustment for current body mass index (BMI) among postmenopausal, but not premenopausal, women (e.g., ≥ 27 vs < 3 MET-h/week, premenopausal HR = 0.83 (0.69-0.98); postmenopausal HR = 0.95 (0.85-1.05); pheterogeneity = 0.99). In analyses of moderate-vigorous activity and breast cancer risk, no heterogeneity by menopausal status was observed (phet ≥ 0.53; e.g., ≥ 27 vs < 3 MET-h/week, ER+/PR+, premenopausal HR = 0.88 (0.69-1.11); postmenopausal HR = 0.71 (0.58-0.88). No associations were observed for ER-/PR- disease.

CONCLUSIONS

Recreational physical activity was associated with lower breast cancer risk in both pre- and postmenopausal women, supporting recreational physical activity as an accessible, modifiable exposure associated with reduced breast cancer risk regardless of menopausal status.

Physical Activity and Bladder Cancer Risk: Findings of the Japan Collaborative Cohort Study

PURPOSE

The association of physical activity with the risk of bladder cancer remains inconsistent among Asian populations. We aimed to examine the association in a large Japanese cohort.

MATERIALS AND METHODS

In a population-based prospective cohort study, a total of 50,374 Japanese adults aged 40-79 years without a history of cancer or cardiovascular disease who had information on physical activity from self-administrated questionnaires were used for analysis. We performed Cox proportional hazard models to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for incident bladder cancer after adjusting for several potential confounders.

RESULTS

During the median 17.5 years of follow-up, 153 incident bladder cancers (116 men and 37 women) were identified. After the multivariable adjustment, HRs (95% CI) of bladder cancer concerning those with recreational sports participation of 1-2 hr/wk, 3-4 hr/wk, and 5 hr/wk and more were 0.67 (0.38-1.20), 0.79 (0.36-1.74), and 0.28 (0.09-0.89), respectively (p for trend=0.017). Compared with mostly sitting at the workplace, occupational physical activity of standing and walking were associated with a lower risk of bladder cancer (HR, 0.53 [95% CI, 0.32 to 0.85]). Hours of daily walking were not associated with the risk. The lower risk of bladder cancer was more evident for recreational sports (HR, 0.33 [95% CI, 0.10 to 1.00]), and for occupational standing and walking activity at work (HR, 0.57 [95% CI, 0.33 to 0.98]) among men.

CONCLUSION

Recreational sports participation and occupational physical activity were inversely associated with the risk of bladder cancer among Japanese, especially in men.

Long-Term Exposure to Walkable Residential Neighborhoods and Risk of Obesity-Related Cancer in the New York University Women's Health Study (NYUWHS)

BACKGROUND

Living in neighborhoods with higher levels of walkability has been associated with a reduced risk of obesity and higher levels of physical activity. Obesity has been linked to increased risk of 13 cancers in women. However, long-term prospective studies of neighborhood walkability and risk for obesity-related cancer are scarce.

OBJECTIVES

We evaluated the association between long-term average neighborhood walkability and obesity-related cancer risk in women.

METHODS

The New York University Women's Health Study (NYUWHS) is a prospective cohort with 14,274 women recruited between 1985 and 1991 in New York City and followed over nearly three decades. We geocoded residential addresses for each participant throughout follow-up and calculated an average annual measure of neighborhood walkability across years of follow-up using data on population density and accessibility to destinations associated with geocoded residential addresses. We used ICD-9 codes to characterize first primary obesity-related cancers and employed Cox proportional hazards models to assess the association between average neighborhood walkability and risk of overall and site-specific obesity-related cancers.

RESULTS

Residing in neighborhoods with a higher walkability level was associated with a reduced risk of overall and site-specific obesity-related cancers. The hazards ratios associated with a 1-standard deviation increase in average annual neighborhood walkability were 0.88 (95% CI: 0.85, 0.93) for overall obesity-related cancer, 0.89 (95% CI: 0.84, 0.95) for postmenopausal breast cancer, 0.82 (95% CI: 0.68, 0.99) for ovarian cancer, 0.87 (95% CI: 0.76, 0.99) for endometrial cancer, and 0.68 (95% CI: 0.49, 0.94) for multiple myeloma, adjusting for potential confounders at both the individual and neighborhood level. The association between neighborhood walkability and risk of overall obesity-related cancer was stronger among women living in neighborhoods with higher levels of poverty compared with women living in areas with lower poverty levels (p Interaction = 0.006 ).

DISCUSSION

Our study highlights a potential protective role of neighborhood walkability in preventing obesity-related cancers in women. https://doi.org/10.1289/EHP11538.

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

OBJECTIVE

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

DESIGN

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

DATA SOURCES

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

ELIGIBILITY CRITERIA

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

RESULTS

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

CONCLUSIONS

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

Genetic associations of leisure sedentary behaviors and the risk of 15 site-specific cancers: A Mendelian randomization study

BACKGROUND AND AIMS

Leisure sedentary behavior (LSB) is associated with the risk of cancer, but the causal relationship between them has not been clarified. The aim of this study was to assess the potential causal association between LSB and risk of 15 site-specific cancers.

METHODS

The causal association between LSB and cancer were assessed with univariate Mendelian randomization (UVMR) and multivariate Mendelian randomization (MVMR). 194 SNPs associated with LSB (from the UK Biobank 408,815 individuals) were adopted as the instrument variables. Sensitivity analyses were performed to ensure the robustness of the results.

RESULTS

UVMR analysis revealed that television watching significantly increased the risk of endometrial cancer (OR = 1.29, 95% CI = 1.02-1.64, p = 0.04) (mainly the endometrioid histology [OR = 1.28, 95% CI = 1.02-1.60, p = 0.031])，breast cancer (OR = 1.16, 95% CI = 1.04-1.30, p = 0.007) (both ER+ breast cancer [OR = 1.17, 95% CI = 1.03-1.33, p = 0.015], and ER- breast cancer [OR = 1.55, 95% CI = 1.26-1.89, p = 2.23 × 10^-5 ]). Although causal association was not found between television watching and ovarian cancer, it was seen in low grade and low malignant potential serous ovarian cancer (OR = 1.49, 95% CI = 1.07-2.08, p = 0.018). However, significant results were not obtained in the UVMR analysis between driving, computer use and the 15 types of cancer. Further MVMR analysis indicated that the above results are independent from most metabolic factors and dietary habits, but mediated by educational attainment.

CONCLUSION

LSB in form of television watching has independent causal association with the risk of endometrial cancer, breast cancer, and ovarian cancer.

A metabolome-wide case-control study of african american breast cancer patients

BACKGROUND

Breast cancer survivors face long-term sequelae compared to the general population, suggesting altered metabolic profiles after breast cancer. We used metabolomics approaches to investigate the metabolic differences between breast cancer patients and women in the general population, aiming to elaborate metabolic changes among breast cancer patients and identify potential targets for clinical interventions to mitigate long-term sequelae.

METHODS

Serum samples were retrieved from 125 breast cancer cases recruited from the Chicago Multiethnic Epidemiologic Breast Cancer Cohort (ChiMEC), and 125 healthy controls selected from Chicago Multiethnic Prevention and Surveillance Study (COMPASS). We used liquid chromatography-high resolution mass spectrometry to obtain untargeted metabolic profiles and partial least squares discriminant analysis (PLS-DA) combined with fold change to select metabolic features associated with breast cancer. Pathway analyses were conducted using Mummichog to identify differentially enriched metabolic pathways among cancer patients. As potential confounders we included age, marital status, tobacco smoking, alcohol drinking, type 2 diabetes, and area deprivation index in our model. Random effects of residence for intercept was also included in the model. We further conducted subgroup analysis by treatment timing (chemotherapy/radiotherapy/surgery), lymph node status, and cancer stages.

RESULTS

The entire study participants were African American. The average ages were 57.1 for cases and 58.0 for controls. We extracted 15,829 features in total, among which 507 features were eventually selected by our criteria. Pathway enrichment analysis of these 507 features identified three differentially enriched metabolic pathways related to prostaglandin, leukotriene, and glycerophospholipid. The three pathways demonstrated inconsistent patterns. Metabolic features in the prostaglandin and leukotriene pathways exhibited increased abundances among cancer patients. In contrast, metabolic intensity in the glycerolphospholipid pathway was deregulated among cancer patients. Subgroup analysis yielded consistent results. However, changes in these pathways were strengthened when only using cases with positive lymph nodes, and attenuated when only using cases with stage I disease.

CONCLUSION

Breast cancer in African American women is associated with increase in serum metabolites involved in prostaglandin and leukotriene pathways, but with decrease in serum metabolites in glycerolphospholipid pathway. Positive lymph nodes and advanced cancer stage may strengthen changes in these pathways.

Interaction of leisure-time physical activity with body mass index on the risk of obesity-related cancers: a pooled study

Physical activity (PA) has been associated with a lower risk of some obesity-related cancers, but the combined association and interaction of PA and body weight on obesity-related cancer risk is less clear. We examined the association of leisure-time PA (high/low) and its combination with body mass index (BMI, <25 [low]/≥25 [high] kg/m² ) on obesity-related cancer risk in 570 021 individuals, aged 43 years on average at baseline, in five Scandinavian cohorts. We used Cox regression to calculate hazard ratios of obesity-related cancers (n = 19 074) and assessed multiplicative and additive interactions between PA and BMI on risk. High leisure-time PA, recorded in 19% of the individuals, was associated with a 7% (95% confidence interval [CI] 4-10%) lower risk of any obesity-related cancer compared to low PA, with similar associations amongst individuals with a low and a high BMI (6% [1-11%] and 7% [2-11%]). High PA was also associated with decreased risks of renal cell (11% [9-31%]) and colon cancer (9% [2-16%]). When high PA and low BMI were combined, the relative risk reduction for all obesity-related cancers was 24% (95% CI 20-28%); endometrial cancer, 47% (35-57%); renal cell cancer, 39% (27-51%); colon cancer, 27% (19-35%); multiple myeloma, 23% (2-40%); and pancreatic cancer, 21% (4-35%), compared to low PA-high BMI. There were no additive or multiplicative interactions between PA and BMI on risk. The result of this study suggests a reduced risk of obesity-related cancer by leisure-time PA in both normal weight and overweight individuals, which further decreased for PA and normal weight combined.

Physical activity, cardiorespiratory fitness, and cognitive function in postmenopausal women with breast cancer

Physical activity may improve cognitive function in women with breast cancer. In a cross-sectional study, we explored the relationship between cognitive function and physical activity (actigraph) and cardiorespiratory fitness (sub-maximal graded exercise test) in 73 postmenopausal women with early stage breast cancer prior to the initiation of systemic adjuvant therapy. Cognitive function was assessed with a standardized battery of neurocognitive measures assessing eight domains. Data were analyzed using partial correlations, controlling for age and total hours of actigraph wear-time. Women were, on average, 63.71 (± 5.3) years of age with 15.47 (± 2.48) years of education. For physical activity, greater average number of steps per day were associated with better attention (r = .262, p = .032) and psychomotor speed (r = .301, p = .011); greater average hours of moderate and moderate/vigorous intensity physical activity were associated with better visual memory (r = .241, p = .049; r = .241, p = .049, respectively); and greater average daily energy expenditure was associated with better visual memory (r = .270, p = .027) and psychomotor speed (r = .292, p = .017). For fitness, higher peak maximum VO2 was associated with better concentration (r = .330, p = .006), verbal memory (r = .241, p = .048), and working memory (r = .281, p = .019). These results suggest that higher levels of physical activity and cardiorespiratory fitness are associated with better cognitive function in postmenopausal women with breast cancer. Randomized controlled trials (RCT) to examine whether physical activity improves cognitive function in women with breast cancer are warranted. These RCTs should also determine the mechanisms of the influence of physical activity on cognitive function. CLINICAL TRIALS REGISTRATION NUMBER: NCT02793921; Date: May 20, 2016.

Association of the Age at Menarche with Site-Specific Cancer Risks in Pooled Data from Nine Cohorts

The average age at menarche declined in European and U.S. populations during the 19th and 20th centuries. The timing of pubertal events may have broad implications for chronic disease risks in aging women. Here we tested for associations of recalled menarcheal age with risks of 19 cancers in 536,450 women [median age, 60 years (range, 31-39 years)] in nine prospective U.S. and European cohorts that enrolled participants from 1981 to 1998. Cox regression estimated multivariable-adjusted HRs and 95% confidence intervals (CI) for associations of the age at menarche with risk of each cancer in each cohort and random-effects meta-analysis was used to generate summary estimates for each cancer. Over a median 10 years of follow-up, 60,968 women were diagnosed with a first primary incident cancer. Inverse linear associations were observed for seven of 19 cancers studied. Each additional year in the age at menarche was associated with reduced risks of endometrial cancer (HR = 0.91; 95% CI, 0.89-0.94), liver cancer (HR = 0.92; 95% CI, 0.85-0.99), melanoma (HR = 0.95; 95% CI, 0.93-0.98), bladder cancer (HR = 0.96; 95% CI, 0.93-0.99), and cancers of the colon (HR = 0.97; 95% CI, 0.96-0.99), lung (HR = 0.98; 95% CI, 0.96-0.99), and breast (HR = 0.98; 95% CI, 0.93-0.99). All but one of these associations remained statistically significant following adjustment for baseline body mass index. Similarities in the observed associations between menarche and seven cancers suggest shared underlying causes rooted early in life. We propose as a testable hypothesis that early exposure to sex hormones increases mid-life cancer risks by altering functional capacities of stem cells with roles in systemic energy balance and tissue homeostasis. SIGNIFICANCE: Age at menarche is associated with risk for seven cancers in middle-aged women, and understanding the shared underlying causal pathways across these cancers may suggest new avenues for cancer prevention.

Sedentary behaviour in the workplace: prevalence, health implications and interventions

INTRODUCTION

This paper reviews the prevalence and health risks of excess sedentary behaviour in office workers, and the effectiveness of sedentary workplace interventions in a manner accessible to practitioners.

SOURCES OF DATA

A narrative review of empirical studies obtained from PubMed and Web of Science.

AREAS OF AGREEMENT

Office workers are highly sedentary, increasing their risk of health problems. Interventions using individual, organisational and environmental level strategies can be effective for reducing workplace sitting.

AREAS OF CONTROVERSY

The effects of sedentary workplace interventions on health are inconsistent. This may be due to a lack of randomized controlled trials powered to detect changes in health outcomes.

GROWING POINTS

Multicomponent interventions that use a combination of the strategies above may be the most effective for reducing sitting.

AREAS TIMELY FOR DEVELOPING RESEARCH

Determining the long-term health and cost-effectiveness of sedentary workplace interventions is a priority to encourage employer buy-in for their implementation.

Targeting the purinergic pathway in breast cancer and its therapeutic applications

Breast cancer (BC) is the most frequent cause of death among women, representing a global public health problem. Here, we aimed to discuss the correlation between the purinergic system and BC, recognizing therapeutic targets. For this, we analyzed the interaction of extracellular nucleotides and nucleosides with the purinergic receptors P1 and P2, as well as the influence of ectonucleotidase enzymes (CD39 and CD73) on tumor progression. A comprehensive bibliographic search was carried out. The relevant articles for this review were found in the PubMed, Scielo, Lilacs, and ScienceDirect databases. It was observed that among the P1 receptors, the A1, A2A, and A2B receptors are involved in the proliferation and invasion of BC, while the A3 receptor is related to the inhibition of tumor growth. Among the P2 receptors, the P2X7 has a dual function. When activated for a short time, it promotes metastasis, but when activated for long periods, it is related to BC cell death. P2Y2 and P2Y6 receptors are related to BC proliferation and invasiveness. Also, the high expression of CD39 and CD73 in BC is strongly related to a worse prognosis. The receptors and ectonucleotidases involved with BC become possible therapeutic targets. Several purinergic pathways have been found to be involved in BC cell survival and progression. In this review, in addition to analyzing the pathways involved, we reviewed the therapeutic interventions already studied for BC related to the purinergic system, as well as to other possible therapeutic targets.

Effects of major lifestyle factors on breast cancer risk: impact of weight, nutrition, physical activity, alcohol and tobacco

Breast cancer (BC) is the most commonly diagnosed cancer and second most common cause of cancer death in US women. Family history and genetics are well-known BC risk factors, but they only account for 15–20% of BC cases. Therefore, in addition to family history, healthcare providers must consider a woman’s modifiable and nonmodifiable personal risk factors that are associated with an increase in BC risk. The World Cancer Research Fund/American Institute for Cancer Research estimate that 30% of BC cases in the US are preventable. Lifestyle education is imperative given the magnitude of BC occurrence. Evidence supports prevention as an effective, long-term strategy for reducing risk. Healthcare providers are key stakeholders in empowering patients to adopt a healthy lifestyle for primary BC prevention. In this paper, we review the available evidence on modifiable BC risk including weight management, nutrition, physical activity, alcohol and tobacco use and provide strategies to counsel patients on lifestyle modifications.

Physical Activity and Breast Cancer Prevention: Possible Role of Immune Mediators

There is strong evidence that physical activity (PA) reduces risk, recurrence, and mortality from breast cancer. Emerging data suggest that PA induces changes in inflammatory and immune mediators that may contribute to beneficial effects on breast cancer outcomes. Thus, the goal of this review was to evaluate the evidence linking the protective benefit of PA to modulation of immune responses in breast cancer. A literature search was conducted to identify studies that evaluated the impact of PA on tumor and immune outcomes in breast cancer patients and in mammary tumor models. Nineteen studies investigated the effect of PA interventions on cancer immune outcomes using preclinical breast cancer models. Tumor growth was reduced in 11 studies, unchanged in three studies, and increased in one study. Spontaneous metastasis was reduced in two studies and survival was improved in four studies. Frequently assessed immune outcomes include splenic cell number and function, circulating inflammatory cytokines, and intratumoral immune cells and inflammatory markers. Circulating inflammatory cytokine responses were heterogeneous in preclinical models. Within the tumor microenvironment (TME), several studies documented a change in the infiltration of immune cells with an increase in effector cells and a reduction in immune suppressive cells. Twenty-three studies investigated the effect of PA interventions on immune outcomes in breast cancer patients. Thirteen studies used aerobic PA interventions and 10 studies used a combination of aerobic and resistance exercise interventions. Cycling and treadmill activities were the most commonly used PA modalities. Circulating immune cells and inflammatory cytokines were the most frequently assessed immune outcomes in the clinical studies. Among the 19 studies that evaluated a PA intervention during the post treatment period, 10 reported a reduction in the levels of at least one inflammatory cytokine. No inflammatory cytokines were quantified in the three studies that evaluated a PA intervention during treatment with chemotherapy. Immune outcomes within the tumor were assessed in only one study performing a PA intervention prior to surgery. Results from preclinical and clinical studies suggest that PA exerts heterogeneous effects on inflammatory cytokines, but may alter the gene expression profile and immune infiltrates in the tumor which may result in a reduction in immunosuppressive factors. However, additional studies are needed to better understand the effect of PA on immune outcomes in the TME.

A mother-centered evaluation of breast pumps

Existing literature outlines mothers' negative experiences with breast pumps, yet a gap exists of which breast pump characteristics are important to mothers. Identifying which breast pump characteristics are important to breast pumping mothers, and any variation between mothers who do or do not work outside of the home, will help identify user needs. A survey collected information on mothers' experiences with breast pumps and impressions of their characteristics. Latent Class Analysis (LCA) was used to determine whether there were possible groupings of impressions of these characteristics. The LCA identified a two-class model with mothers' age as a significant covariate. Portability, ease of use, low-weight, fast milk extraction, comfortability, low-noise, and discreet were all found to be important to one group of mothers, while only portability, ease of use, fast milk extraction, and comfortability were found to be important to another group of mothers. Mothers' work status was not a significant covariate but did predict class membership when considered as a grouping variable in conjunction with age. Breast pumping mothers' needs were found to differ based on their work status and age together, and collecting and considering these different needs is vital to creating redesigns that improve mothers' breast pumping experience.

[Evaluation of a pilot program of physical activity prescription in primary care in the Valencian Community (Spain)]

OBJECTIVE

Assess the prescription process, adherence and impact on health measured in improvement of self-esteem and health-related quality of life, as short-term health indicators, from a pilot study of prescription of physical activity assets for 3 months.

METHOD

Quasi-experimental study before-after without a control group, for the evaluation of the pilot phase (November 2017 and May 2018) of the program Conecta Actius per a la Salut in the Valencian Community (Spain). The physical activity prescription was performed and a questionnaire was completed at the beginning (T0) and at 3 months (T1). A descriptive analysis was carried out by sex and educational level where the differences between T0 and T1 were calculated using chi square and the Wilcoxon test of two dependent samples.

RESULTS

The sample was 82 in T0 and 78 people in T1. The analysis shows an improvement between quality of life (7%; p ≤0.001), health perception (12,5%; p ≤0.001) and self-esteem (5,9%; p ≤0.001) between T0 and T1. The improvement proportion in Health perception is greater in women than in men for the three measured scales and in those who have a higher educational level or have been prescribed in centers that offer a single asset.

CONCLUSION

Pilot study shows short-term health benefits after the physical activity prescription. Specifically, there is an improvement in the quality of life, health perception and self-esteem of the population.

The association between recreational screen time and cancer risk: findings from the UK Biobank, a large prospective cohort study

Background

Evidence is suggestive of sedentary behaviour being associated with an increased risk of endometrial cancer, but the evidence base is too limited to draw any conclusions for other cancers. The aim of the study was to investigate the association between recreational screen time and site-specific cancer risk.

Methods

We analysed data from the prospective UK Biobank cohort study. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between daily recreational screen time (including television (TV) viewing time, computer use time and total screen time) and site-specific cancer risk. Partition models and isotemporal substitution models investigated the impact of substituting recreational screen time with physical activity.

Results

During a mean follow-up of 7.6 years, 28,992 incident cancers were identified among 470,578 adults. A 1-h increase in daily TV viewing time was associated with higher risks of oropharyngeal, oesophago-gastric and colon cancer in fully adjusted models. Participants who reported ≤1, compared with 1- ≤ 3, hours/day of TV viewing time had lower risks of lung, breast, and oesophago-gastric cancer. Findings were inconsistent for daily recreational computer use and daily total recreational screen time. The majority of observed associations were small, and were attenuated after excluding cancers diagnosed within the first two years of follow-up, except for oesophago-gastric and colon cancers (HR 1.05, 95% CI: 1.01, 1.10; and HR 1.04, 95% CI: 1.01, 1.07 per 1-h increase in daily TV viewing time, respectively). However, isotemporal substitution models showed reduced risk of some site-specific (oropharyngeal, lung, breast and colorectal) cancers when replacing 1-h/day of TV viewing with 1-h of moderate-intensity physical activity or walking.

Conclusions

Our findings show that daily recreational screen time, particularly TV viewing, was associated with small increased risks of oesophago-gastric and colon cancer. Replacing 1-h/day of TV viewing with 1-h of moderate-intensity physical activity or walking was associated with lower risk of oropharyngeal, lung, breast and colorectal cancers. Further research from other large prospective cohort studies is required, while mechanistic research is warranted to enhance the biological plausibility of these findings.

Sedentary behavior and risk of breast cancer: a dose-response meta-analysis from prospective studies

BACKGROUND

Emerging studies examined the association between sedentary behavior and risk of breast cancer, however, the dose-response relationship remained unclear. We aim to explore dose-response relationship of sedentary behavior and breast cancer risk based on relevant cohort studies.

METHODS

Online database (PubMed, Web of Science, EMBASE and Cochrane Library) were searched up to March 29, 2019. Overall relative risk (RR) with 95% confidence interval (CI) were pooled, and generalized least squares (GLS) method and restricted cubic splines were applied to evaluate the linear or nonlinear relation. Attributable risk proportion (ARP) was used to assess the health hazards of sedentary behavior in different countries.

RESULTS

Eight prospective studies were included in the meta-analysis, containing 17 048 breast cancer cases and 426 506 participants. The borderline statistical association was detected between prolonged sedentary behavior and risk of breast cancer (RR 1.08, 95% CI 0.99-1.19). Linear association between sedentary and breast cancer was observed (P_nonlinearity = 0.262), and for 1 h/d increment of sedentary behavior, there was 1% increase of breast cancer risk (RR 1.01, 95% CI1.00-1.02). Similar results were also found between TV viewing and risk of breast cancer (P_nonlinearity = 0.551), with 1 h/day increment of TV viewing daily attributing to 2% increase of breast cancer risk (RR 1.02, 95% CI 1.00-1.04). Moreover, sedentary behavior may statistically increase the risk of breast cancer by 21.6% for Asian countries, 8.26% for North America.

CONCLUSIONS

Sedentary behavior was validated as a risk factor of breast cancer through dose-response analysis, especially TV viewing.

Risk Factors and Outcomes During a First Acute Myocardial Infarction in Breast Cancer Survivors Compared with Females Without Breast Cancer

PURPOSE

The purpose of this research was to study the differences in epidemiology and outcomes of a first myocardial infarction in breast cancer survivors compared with the general female population in the United States.

METHODS

We retrospectively analyzed the US National Inpatient Sample years 2005-2015 to identify adult women with a first myocardial infarction. In this cohort, breast cancer survivors were identified. Outcomes evaluated were the differences in baseline demographics, comorbidities, and adjusted in-hospital mortality in women with and without breast cancer.

RESULTS

Among 1,644,032 first myocardial infarction cases in adult women, there were 56,842 (3.5%) breast cancer survivors. Compared with women without breast cancer, breast cancer survivors were 6 years older (mean age 77 vs 71 years, P < .001), had significantly higher prevalence of dyslipidemia and hypertension, and lower prevalence of obesity, diabetes mellitus, and smoking. Breast cancer survivors were more likely to have a non-ST segment elevation acute myocardial infarction and less likely to receive mechanical revascularization. In-hospital mortality was lower in breast cancer survivors (7.1%) compared with those without (7.9%, P < .001), findings that persisted after risk adjustment (odds ratio 0.89; 95% CI, 0.82-0.94).

CONCLUSIONS

Breast cancer survivors had a first acute myocardial infarction at an older age and had small but favorable differences in cardiovascular disease risk factors and outcomes compared with women without breast cancer. The favorable impact of health education, preventative medical care, greater motivation for a healthier lifestyle, and participation in cancer survivorship programs on these seemingly paradoxical findings in breast cancer survivors should be further explored.

Walking and biologic ageing: Evidence based on NHANES telomere data

The length of telomeres is an objective measure of biologic ageing. This study evaluated the extent minutes of walking per week are associated with leukocyte telomere length (LTL) in a random sample of 5,823 U.S. adults. The investigation was cross-sectional and data were obtained from the National Health and Nutrition Examination Survey (NHANES). LTL was measured by the quantitative polymerase chain reaction method. Walking minutes was calculated from walking frequency and duration measures. Results showed that for each year of chronological age, telomeres were 15.6 base pairs shorter (P < 0.0001). With walking minutes and LTL treated as continuous variables, the relationship was quadratic, not linear (F = 11.2, P = 0.0023). With walking time divided into three categories, adults who performed ≥ 150 minutes of walking per week had longer telomeres than those who did no regular walking, and those who did some, but less than the recommendation (F = 5.0, P = 0.0137). Regular walkers were estimated to have a biologic ageing advantage associated with 6.5-7.6 years less biologic ageing compared to non-walkers, after adjusting for covariates. Additional investigations designed to study causality and the mechanisms associated with the walking and LTL relationship are needed.

Clinical features and first degree relative breast cancer, their correlation with histological tumor grade: a 5-year retrospective case study of breast cancer in Mizoram, India

The aim was to assess the association of histological tumor grade with other clinical features and epidemiological factors of women with invasive breast carcinoma. A retrospective study of 103 Mizo breast cancer patients visiting hospitals was made in Aizawl, Mizoram, Northeast India. With a prior consent, information on epidemiological factors and family history in relation to cancer was obtained. Clinical reports were obtained from their medical records. The frequency of distribution was calculated for age at diagnosis and tumor characteristics. Statistical analysis for different variables was done using a chi-square test. p < 0.05 was considered significant. The histological tumor grades in our studies were found to be associated with lymph node invasion (p < 0.021), different subtype of hormone receptor such as ER status (p < 0.004), ER/PR status (p < 0.007), HER2/neu status (p < 0.014), and ER/PR/HER2 status (p < 0.025). A patient with a family history of breast cancer in their 1st degree relative is also seen to have association in determining the tumor grade (p < 0.003). Reproductive history, lifestyle and dietary habits, tobacco, and alcohol consumption were found to have no influence on breast cancer tumor grade. Our results showing significant correlation between status of lymph node, ER, PR, and HER2/neu oncoprotein and family history with 1st degree relative breast cancer are the first time report to target and focus on the possible role of biomarkers for diagnosis among the Mizo tribal breast cancer patients.

World Cancer Research Fund International: Continuous Update Project-systematic literature review and meta-analysis of observational cohort studies on physical activity, sedentary behavior, adiposity, and weight change and breast cancer risk

PURPOSE

The purpose of the present study was to systematically review the complex associations between energy balance-related factors and breast cancer risk, for which previous evidence has suggested different associations in the life course of women and by hormone receptor (HR) status of the tumor.

METHODS

Relevant publications on adulthood physical activity, sedentary behavior, body mass index (BMI), waist and hip circumferences, waist-to-hip ratio, and weight change and pre- and postmenopausal breast cancer risk were identified in PubMed up to 30 April 2017. Random-effects meta-analyses were conducted to summarize the relative risks across studies.

RESULTS

One hundred and twenty-six observational cohort studies comprising over 22,900 premenopausal and 103,000 postmenopausal breast cancer cases were meta-analyzed. Higher physical activity was inversely associated with both pre- and postmenopausal breast cancers, whereas increased sitting time was positively associated with postmenopausal breast cancer. Although higher early adult BMI (ages 18-30 years) was inversely associated with pre- and postmenopausal breast cancers, adult weight gain and greater body adiposity increased breast cancer risk in postmenopausal women, and the increased risk was evident for HR+ but not HR- breast cancers, and among never but not current users of postmenopausal hormones. The evidence was less consistent in premenopausal women. There were no associations with adult weight gain, inverse associations with adult BMI (study baseline) and hip circumference, and non-significant associations with waist circumference and waist-to-hip ratio that were reverted to positive associations on average in studies accounting for BMI. No significant associations were observed for HR-defined premenopausal breast cancers.

CONCLUSION

Better understanding on the impact of these factors on pre- and postmenopausal breast cancers and their subtypes along the life course is needed.

Weight Management and Physical Activity for Breast Cancer Prevention and Control

Observational evidence has consistently linked excess adiposity and inactivity to increased breast cancer risk and to poor outcomes in individuals diagnosed with early-stage, potentially curable breast cancer. There is less information from clinical trials testing the effect of weight management or physical activity interventions on breast cancer risk or outcomes, but a number of ongoing trials will test the impact of weight loss and other lifestyle changes after cancer diagnosis on the risk of breast cancer recurrence. Lifestyle changes have additional benefits beyond their potential to decrease primary or secondary breast cancer risk, including improvements in metabolic parameters, reduction in the risk of comorbidities such as diabetes and heart disease, improvement of physical functioning, and mitigation of side effects of cancer therapy. Despite these myriad benefits, implementation of lifestyle interventions in at-risk and survivor populations has been limited to date. This article reviews the evidence linking lifestyle factors to breast cancer risk and outcomes, discusses completed and ongoing randomized trials testing the impact of lifestyle change in primary and secondary breast cancer prevention, and reviews efforts to implement and disseminate lifestyle interventions in at-risk and breast cancer survivor populations.

Health and Racial Disparity in Breast Cancer

Breast cancer is the most common noncutaneous malignancy and the second most lethal form of cancer among women in the United States. It currently affects more than one in ten women worldwide. The chance for a female to be diagnosed with breast cancer during her lifetime has significantly increased from 1 in 11 women in 1975 to 1 in 8 women (Altekruse, SEER Cancer Statistics Review, 1975-2007. National Cancer Institute, Bethesda, 2010). This chance for a female of being diagnosed with cancer generally increases with age (Howlader et al, SEER Cancer Statistics Review, 1975-2010. National Cancer Institute, Bethesda, 2013). Fortunately, the mortality rate from breast cancer has decreased in recent years due to increased emphasis on early detection and more effective treatments in the White population. Although the mortality rates have declined in some ethnic populations, the overall cancer incidence among African American and Hispanic population has continued to grow. The goal of the work presented in this book chapter is to highlight similarities and differences in breast cancer morbidity and mortality rates among non-Hispanic white and non-Hispanic black populations. This book chapter also provides an overview of breast cancer, racial/ethnic disparities in breast cancer, breast cancer incidence and mortality rate linked to hereditary, major risk factors of breast cancer among minority population, breast cancer treatment, and health disparity. A considerable amount of breast cancer treatment research have been conducted, but with limited success for African Americans compared to other ethnic groups. Therefore, new strategies and approaches are needed to promote breast cancer prevention, improve survival rates, reduce breast cancer mortality, and ultimately improve the health outcomes of racial/ethnic minorities. In addition, it is vital that leaders and medical professionals from minority population groups be represented in decision-making in research so that racial disparity in breast cancer can be well-studied, fully addressed, and ultimately eliminated in breast cancer.

Physical Activity and Risk of Breast Cancer: A Meta-Analysis of 38 Cohort Studies in 45 Study Reports

OBJECTIVES

To evaluate and quantify the association between physical activity (PA) and risk of breast cancer.

METHODS

A systematic review meta-analysis was conducted. The literature was independently and manually searched by 2 reviewers through 3 English databases (PubMed, Embase, and ISI Web of Science) for data till October 2017. The quality of included studies was assessed by the Newcastle-Ottawa Quality Assessment Scale. Fixed-effects models were used to estimate the pooled relative risk and 95% confidence intervals (95% CI). Dose-response analysis was chosen for quantifying the association between PA and risk of breast cancer. The Begg test and the Egger test were used to estimate potential publication bias. Heterogeneity between studies was evaluated with I² statistics.

RESULTS

The meta-analysis included 38 cohort studies published between 1994 and 2017, which included 68 416 breast cancer cases. The overall relative risk (ORR) for breast cancer was 0.87 (95% CI 0.84-0.90). The inverse association was consistent among all subgroup analyses. In subgroup analysis by menopausal status, the ORR of breast cancer was 0.83 (95% CI 0.79-0.87) for premenopausal status and 0.91 (95% CI 0.85-0.97) for postmenopausal status. In subgroup analysis by PA type, the ORR for total activity was 0.87 (95% CI 0.81-0.93), for recreational activity 0.88 (95% CI 0.85-0.91), for occupational activity 0.91 (95% CI 0.84-0.99), and for nonoccupational activity 0.87 (95% CI 0.83-0.92). The risk of breast cancer was significantly lower in people with exposure periods longer than 1 year and less than 5 years (ORR 0.62; 95% CI 0.46-0.78), followed by those with lifetime activity (ORR 0.81; 95% CI 0.69-0.93). The ORR for subjects with body mass index of less than 25 kg/m² (0.88; 95% CI 0.83-0.93) was close to that for subjects with body mass index of more than 25 kg/m² (0.87; 95% CI 0.77-0.97). A linear relationship was found between breast cancer risk and PA (recreational activity and total activity), and the ORR was reduced by 3% (95% CI 0.95-0.99) for every 10 metabolic equivalent of energy hours per week increment in recreational PA and by 2% (95% CI 0.97-0.99) for every 10 metabolic equivalent of energy hours per week increment in total PA.

CONCLUSIONS

PA is significantly associated with a decrease in the risk of breast cancer.

Dietary Habits and Physical Activity are Associated With the Risk of Breast Cancer Among Young Iranian Women: A Case-control Study on 1010 Premenopausal Women

BACKGROUND

Several studies conducted in developed countries introduced diet and physical inactivity as major risk factors for several types of cancers. However, the impact of diet and physical inactivity on the risk of breast cancer (BC) is understudied, and the limited findings are controversial. In addition, no or limited knowledge is available from the developing world.

PATIENTS AND METHODS

This case-control study was performed from November 2014 to March 2016 on 1010 young women aged 20 to 50 years who were newly diagnosed with BC. Data was obtained via a validated questionnaire and the global physical activity questionnaire (GPAQ2). Also, patients' medical and histopathology reports were reviewed.

RESULTS

The results of multiple logistic regression suggested that, except for the common risk factors for BC (older marital age, family history of BC, smoking, and being a passive smoker), eating red meat (adjusted odds ratio [aOR] >8 portions/week [p/w] vs. 0-2 p/w, 1.15; 95% confidence interval [CI], 1.04-1.28); eating fish (aOR >8 p/w vs. 0-2 p/w, 1.55; 95% CI, 1.12-2.76), fruit consumption (aOR 0-4 p/w vs. >8 p/w, 1.96; 95% CI, 1.07-3.82), pickle consumption (aOR >8 p/w vs. 7-8 p/w, 1.46; 95% CI, 1.31-1.70), and intensity of physical activity (aOR light vs. vigorous, 1.68; 95% CI, 1.47-1.98) were directly associated with a higher risk of BC in young women.

CONCLUSION

Our study supported the hypothesis that unhealthy dietary habits and physical inactivity are risk factors for BC. We found that a healthy diet containing low fat and high fruits and vegetables with regular exercise are effective ways to reduce the risk of BC among young women.

The associations of sitting time and physical activity on total and site-specific cancer incidence: Results from the HUNT study, Norway

Background

Sedentary behavior is thought to pose different risks to those attributable to physical inactivity. However, few studies have examined the association between physical activity and sitting time with cancer incidence within the same population.

Methods

We followed 38,154 healthy Norwegian adults in the Nord-Trøndelag Health Study (HUNT) for cancer incidence from 1995–97 to 2014. Cox proportional hazards regression was used to estimate risk of site-specific and total cancer incidence by baseline sitting time and physical activity.

Results

During the 16-years follow-up, 4,196 (11%) persons were diagnosed with cancer. We found no evidence that people who had prolonged sitting per day or had low levels of physical activity had an increased risk of total cancer incidence, compared to those who had low sitting time and were physically active. In the multivariate model, sitting ≥8 h/day was associated with 22% (95% CI, 1.05–1.42) higher risk of prostate cancer compared to sitting <8 h/day. Further, men with low physical activity (≤8.3 MET-h/week) had 31% (95% CI, 1.00–1.70) increased risk of colorectal cancer (CRC) and 45% (95% CI, 1.01–2.09) increased risk of lung cancer compared to participants with a high physical activity (>16.6 MET-h/week). The joint effects of physical activity and sitting time the indicated that prolonged sitting time increased the risk of CRC independent of physical activity in men.

Conclusions

Our findings suggest that prolonged sitting and low physical activity are positively associated with colorectal-, prostate- and lung cancer among men. Sitting time and physical activity were not associated with cancer incidence among women. The findings emphasizing the importance of reducing sitting time and increasing physical activity.

Exercise and cancer mortality in Korean men and women: a prospective cohort study

Background

Little is known about longitudinal associations of exercise with different types of cancer, particularly in Asian populations. The purpose of this research was to estimate the association between the duration of exercise and all-cause and cancer-specific mortality.

Method

Data were obtained from the Korean Metabolic Syndrome Mortality Study (KMSMS), a prospective cohort study of 303,428 Korean adults aged 20 years or older at baseline between 1994 and 2004 after exclusion of individuals with missing variables on smoking and exercise. Death certificate-linked data until 31 December 2015 were provided by the Korean National Statistical Office. Cox regression models were constructed to evaluate the associations of exercise with cancer mortality after adjusting for potential confounders such as age, alcohol consumption and smoking status.

Results

During the follow-up period of 15.3 years (4,638,863 person-years), a total of 16,884 participants died. Both men and women who exercised showed approximately 30% decreased hazards of mortality, compared to those who did no exercise (hazard ratio (HR) 0.70, 95% confidence interval (CI)=0.68-0.73 for men, HR=0.71, CI : 0.67-0.75). A notable observation of this study is the curvilinear associations between the total duration of exercise per week and cancer mortality, with the lowest risk being observed at the low-to-medium levels of exercise; this trend of associations was found for esophagus, liver, lung, and colorectal cancer mortality in men, and all-cause, all-cancer and lung cancer mortality in women.

Conclusions

Individuals who exercised showed considerably lower all-cause and cancer mortality risks compared with those who did no exercise. Policies and clinical trials aimed at promoting minimal or moderate participation in exercise may minimize cancer mortality risk.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5669-1) contains supplementary material, which is available to authorized users.

Walking in Relation to Mortality in a Large Prospective Cohort of Older U.S. Adults

INTRODUCTION

Engaging in >150 minutes of moderate-intensity or 75 minutes of vigorous-intensity physical activity weekly is recommended for optimal health. The relationship between walking, the most common activity especially for older adults, and total mortality is not well documented.

METHODS

Data from a large U.S. prospective cohort study including 62,178 men (mean age 70.7 years) and 77,077 women (mean age 68.9 years), among whom 24,688 men and 18,933 women died during 13 years of follow-up (1999-2012), were used to compute multivariable-adjusted hazard rate ratios and 95% CIs for walking as the sole form of activity or adjusted for other moderate- or vigorous-intensity physical activity in relation to total and cause-specific mortality (data analysis 2015-2016).

RESULTS

Inactivity compared with walking only at less than recommended levels was associated with higher all-cause mortality (hazard rate ratio=1.26, 95% CI=1.21, 1.31). Meeting one to two times the recommendations through walking only was associated with lower all-cause mortality (hazard rate ratio=0.80, 95% CI=0.78, 0.83). Associations with walking adjusted for other moderate- or vigorous-intensity physical activity were similar to walking only. Walking was most strongly associated with respiratory disease mortality followed by cardiovascular disease mortality and then cancer mortality.

CONCLUSIONS

In older adults, walking below minimum recommended levels is associated with lower all-cause mortality compared with inactivity. Walking at or above physical activity recommendations is associated with even greater decreased risk. Walking is simple, free, and does not require any training, and thus is an ideal activity for most Americans, especially as they age.

Long-term endurance training increases serum cathepsin S levels in healthy female subjects

BACKGROUND

Circulating cathepsin S (CS) has been associated with a lower risk for breast cancer in a large Swedish cohort. Long-term physical activity has been shown to have beneficial effects on the development of various cancer subtypes, in particular breast and colorectal cancers. The aim of this study was to investigate the effect of long-term endurance sport on CS levels in females.

MATERIAL AND METHODS

Thirty-six of 40 subjects completed the study. Subjects were told to increase their activity pensum for 8 months reaching 150 min/week moderate or 75 min/week intense exercise. Ergometries were performed at the beginning and the end of the study to prove/quantify the performance gain. Blood samples were drawn at baseline and every 2 months. Serum CS levels were measured by ELISA. To analyse the change and the progression of CS, Wilcoxon rank sum and Friedman tests were used.

RESULTS

The sportive group (performance gain by > 4.9%) showed a significant increase of CS levels from 3.32/2.73/4.09 to 4.00/3.09/5.04 ng/ml (p = 0.008) corresponding to an increase of 20.5%.

CONCLUSIONS

We could show a significant increase of circulating CS levels in healthy female subjects induced by long-term physical activity. CS, occurring in the tumour microenvironment, is well-known to promote tumour growth, e.g. by ameliorating angiogenesis. However, the role of circulating CS in cancer growth is not clear. As physical activity is known as preventive intervention, in particular concerning breast and colorectal cancers, and long-term physical activity leads to an increase of CS levels in female subjects, circulating CS might even be involved in this protective effect.

TRIAL REGISTRATION

Clinical trial registration: NCT02097199.

Breast Cancer Epidemiology, Prevention, and Screening

Globally, breast cancer is both the most commonly occurring cancer and the commonest cause of cancer death among women. Available data suggest that incidence and mortality in high-resource countries has been declining whereas incidence and mortality in low-resource countries has been increasing. This pattern is likely to be due to changing risk factor profiles and differences in access to breast cancer early detection and treatment. Risk factors for breast cancer include increasing age, race, menarche history, breast characteristics, reproductive patterns, hormone use, alcohol use, tobacco use, diet, physical activity, and body habitus. Mutations in the BRCA 1 and BRCA 2 tumor suppressor genes are significantly associated with the development of breast and ovarian cancer by the age of 70. Survival depends on both stage and molecular subtype. As there are few signs and symptoms early on, early detection is an important strategy to improve outcomes. Major professional organizations in the United States and elsewhere recommend screening with mammography with appropriate follow up for an abnormal screening test, although they differ somewhat by recommended ages and frequency of screening. Studies suggest a 15%-40% mortality reduction secondary to screening, however, there are also concerns about harms, such as overdiagnosis (5%-54%) and overtreatment leading to long term complications, and false negatives (6%-46%). Identification of women at risk for BRCA1 and BRCA 2 mutations is also recommended with referral for genetic testing. Preventive interventions, such as lifestyle, medical, and surgical options are available for women testing positive for BRCA mutations.

The relationship between physical activity, obesity, and lung cancer risk by smoking status in a large prospective cohort of US adults

Physical activity has been associated with lower lung cancer risk in numerous studies with estimates ranging from 20 to 50% lower risk in the most versus the least active study participants. Underweight and obesity have also been associated with lower lung cancer risk, with a nonlinear, inverted U-shaped relationship. However, associations of physical activity and obesity with lung cancer are likely significantly confounded by smoking since individuals who smoke are generally less active and leaner than non-smokers, but few studies have examined these associations stratified by smoking status. Using data from 162,679 men and women who were cancer-free at enrollment (1992-1993) in the American Cancer Society Cancer Prevention Study-II Nutrition Cohort, we examined associations of baseline recreational physical activity (MET-hours per week; none, 0.1 to <8.75 (reference), 8.75-17.4, 17.5+ MET-hours/week), baseline body mass index (BMI, weight (kg)/height (m²); <18.5, 18.5-22.0 (reference), 22.1-24.9, 25.0-29.9, 30.0+ kg/m²), and waist circumference (measured in 1997; sex-specific quartiles) in relation to lung cancer risk stratified by smoking status and years since quitting among former smokers (never, current, former <10 years, former, 10-19 years, former 20+ years). Cox proportional hazards modeling computed hazard rate ratios (RR) and 95% confidence intervals (CI) while adjusting for potential confounders. During 2,384,546 person years of follow-up time, 4,669 men and women were diagnosed with lung cancer (453 among never smokers; 1,452 among current smokers; 1,194 among former smokers <10 years since quitting; 725 among former 10-19 years; and 845 among former 20+ years). Physical activity was not associated with lung cancer risk within any of the smoking strata except in former smokers less than 10 years since quitting (RR = 0.77; 95% CI 0.67-0.90 for 17.5+ MET-hours/week). Similarly, BMI was inversely associated with lung cancer in former smokers less than 10 years since quitting (RR = 0.68; 95% CI 0.55-0.84 for 30+ kg/m²) and more modestly in former smokers who quit 10-19 and 20+ years ago. Waist circumference was not associated with lung cancer risk in any smoking category. While being physically active and maintaining a healthy body weight are important for prevention of various chronic diseases, including several types of cancer, our results suggest that physical activity, BMI, and waist circumference are not associated with lung cancer risk, regardless of smoking status.

Cardiovascular disease and mortality after breast cancer in postmenopausal women: Results from the Women's Health Initiative

Background

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality among older postmenopausal women. The impact of postmenopausal breast cancer on CVD for older women is uncertain. We hypothesized that older postmenopausal women with breast cancer would be at a higher risk of CVD than similar aged women without breast cancer and that CVD would be a major contributor to the subsequent morbidity and mortality.

Methods

In a prospective Women’s Health Initiative study, incident CVD events and total and cause-specific death rates were compared between postmenopausal women with (n = 4,340) and without (n = 97,576) incident invasive breast cancer over 10 years post-diagnosis, stratified by 3 age groups (50–59, 60–69, and 70–79).

Results

Postmenopausal women, regardless of breast cancer diagnosis, had similar and high levels of CVD risk factors (e.g., smoking and hypertension) at baseline prior to breast cancer, which were strong predictors of CVD and total mortality over time. CVD affected mostly women age 70–79 with localized breast cancer (79% of breast cancer cases in 70–79 age group): only 17% died from breast cancer and CVD was the leading cause of death (22%) over the average 10 years follow up. Compared to age-matched women without breast cancer, women age 70–79 at diagnosis of localized breast cancer had a similar multivariate-adjusted hazard ratio (HR) of 1.01 (95% confidence interval [CI]: 0.76–1.33) for coronary heart disease, a lower risk of composite CVD (HR = 0.84, 95% CI: 0.70–1.00), and a higher risk of total mortality (HR = 1.20, 95% CI: 1.04–1.39).

Conclusion

CVD was a major contributor to mortality in women with localized breast cancer at age 70–79. Further studies are needed to evaluate both screening and treatment of localized breast cancer tailored to the specific health issues of older women.

Cardiovascular and hemodynamic responses to adapted physical exercises in very old adults

BACKGROUND

Aging is characterized by a physiological reduction in physical activity, which is inversely correlated with survival.

AIMS

Aim of the present study is to evaluate the cardiovascular, central hemodynamic and autonomic responses to a single bout of adapted physical exercise in octogenarian subjects.

METHODS

We studied cardiovascular, hemodynamic and autonomic responses to adapted physical activity in 33 subjects by a noninvasive methodology (Nexfin^®, Edwards Lifesciences Corporation).

RESULTS

Our octogenarians presented a significant increase in mean arterial pressure (p < 0.01) and heart rate (p < 0.005) in response to exercise, while both are reduced during the early recovery phase. Central hemodynamic showed a significant increase in stroke volume (p < 0.05), cardiac output (p < 0.01) and left ventricle contractility index (p < 0.01), whereas systemic vascular resistance showed a significant decrease (p < 0.001). We found a reduction in baroreflex control of the sinus node during exercise.

DISCUSSION

Our data demonstrate that in very old people adapted physical activity is able to activate cardiovascular system and to induce a postexercise hypotension similarly to adults. The baroreflex control of sinus node seems to contribute in the physiological mechanism of these cardiovascular adaptations.

CONCLUSIONS

In very old people, physical activity induces cardiovascular and hemodynamic responses not significantly different from those induced in adult even though some cautions particularly in the early recovery phase after exercise should be exercised.

A Comprehensive Lifestyle Randomized Clinical Trial: Design and Initial Patient Experience

Background: Although epidemiological research demonstrates that there is an association between lifestyle factors and risk of breast cancer recurrence, progression of disease, and mortality, no comprehensive lifestyle change clinical trials have been conducted to determine if changing multiple risk factors leads to changes in biobehavioral processes and clinical outcomes in women with breast cancer. This article describes the design, feasibility, adherence to the intervention and data collection, and patient experience of a comprehensive lifestyle change clinical trial (CompLife). Methods: CompLife is a randomized, controlled trial of a multiple-behavior intervention focusing on diet, exercise, and mind-body practice along with behavioral counseling to support change. The initial exposure to the intervention takes place during the 4 to 6 weeks of radiotherapy (XRT) for women with stage III breast cancer and then across the subsequent 12 months. The intervention group will have 42 hours of in-person lifestyle counseling during XRT (7-10 hours a week) followed by up to 30 hours of counseling via video connection for the subsequent 12 months (weekly sessions for 6 months and then monthly for 6 months). The primary outcome is disease-free survival. Multiple secondary outcomes are being evaluated, including: (1) biological pathways; (2) overall survival; (3) patient-reported outcomes; (4) dietary patterns/fitness levels, anthropometrics, and body composition; and (5) economic outcomes. Qualitative data of the patient experience in the trial is collected from exit interviews, concluding remarks, direct email correspondences, and web postings from patients. Results: Fifty-five patients have been recruited and randomized to the trial to date. Accrual of eligible patients is high (72%) and dropout rates extremely low (5%). Attendance to the in-person sessions is high (95% attending greater than 80% of sessions) as well as to the 30 hours of video counseling (88% attending more than 70% of sessions). Adherence to components of the behavior change intervention is high and compliance with the intensive amount of data collection is exceptional. Qualitative data collected from the participants reveals testimonials supporting the importance of the comprehensive nature of intervention, especially the mind-body/mindfulness component and social support, and meaningful lifestyle transformations. Conclusion: Conducting a comprehensive, multicomponent, lifestyle change clinical trial for women with breast was feasible and collection of biobehavioral outcomes successful. Adherence to behavior change was high and patient experience was overwhelmingly positive.

Sedentary time and breast cancer incidence in African American women

PURPOSE

The objective of this study was to evaluate whether time spent sitting at work or watching television was associated with breast cancer risk among African American women.

METHODS

The Black Women's Health Study (analytic cohort = 46,734) is an ongoing prospective cohort study of African American women ages 21-69 at baseline (1995). Questionnaire data were used to estimate sedentary time. Total time spent sitting at work and watching television (individually and combined) at baseline and updated through follow-up (1995-2001) and breast cancer incidence (n = 2,041 incident cases, 1995-2013) was evaluated using proportional hazards regression.

RESULTS

Higher total time spent sitting at baseline (≥10 vs. <5 h/day, HR 1.27, 95 % CI 1.06, 1.53) and updated through follow-up (≥10 vs. <5 h/day, HR 1.38, 95 % CI 1.14, 1.66) was associated with an increased breast cancer risk. Associations were stronger for hormone receptor-negative tumors (≥10 vs. <5 h/day, HR 1.70, 95 % CI 1.12, 2.55) compared to hormone receptor-positive tumors (≥10 vs. <5 h/day, HR 1.16, 95 % CI 0.88, 1.52), but tests for heterogeneity were not statistically significant (p heterogeneity = 0.31). Positive associations between total time spent sitting and breast cancer incidence did not differ by physical activity level or body composition measurements.

CONCLUSIONS

Our findings suggest that high sedentary time may increase risk for breast cancer among African American women.

Sedentary work and the risk of breast cancer in premenopausal and postmenopausal women: a pooled analysis of two case-control studies

OBJECTIVES

There is limited research on the association between sedentary behaviour and breast cancer risk, particularly whether sedentary behaviour is differentially associated with premenopausal and postmenopausal breast cancer. We pooled data from 2 case-control studies from Australia and Canada to investigate this association.

METHODS

This pooled analysis included 1762 incident breast cancer cases and 2532 controls. Participants in both studies completed a lifetime occupational history and self-rated occupational physical activity level. A job-exposure matrix (JEM) was also applied to job titles to assess sedentary work. Logistic regression analyses (6 pooled and 12 study-specific) were conducted to estimate associations between both self-reported and JEM-assessed sedentary work and breast cancer risk among premenopausal and postmenopausal women.

RESULTS

No association was observed in the 6 pooled analyses, and 10 of the study-specific analyses also showed null results. 2 study-specific analyses provided inconsistent and contradictory results, with 1 showing statistically significant increased risk of breast cancer for self-reported sedentary work among premenopausal women cancer in the Canadian study, and the other a non-significant inverse association between JEM-assessed sedentary work and breast cancer risk among postmenopausal women in the Australian study.

CONCLUSIONS

While a suggestion of increased risk was seen for premenopausal women in the Canadian study when using the self-reported measure, overall this pooled study does not provide evidence that sedentary work is associated with breast cancer risk.

Physical exercise modulates the level of serum MMP-2 and MMP-9 in patients with breast cancer

Matrix metalloproteinases (MMPs) exhibit an important function in extracellular matrix degradation. MMPs modulate the activation of growth factors, cytokines and metastasis. At present, the effect of exercise on serum levels of MMP-2 and -9 remains unclear. The aim of the present study was to investigate the effect of various physical activities on the circulating levels of MMP-2 and -9 in breast cancer (BC) survivors and healthy subjects. A total of 66 female subjects were enrolled in the present study. The cohort included 46 BC survivors and 20 healthy subjects divided into 5 groups: Group A (17 BC survivors, participating in recreational dragon boat paddling), group B (14 BC survivors, participating in recreational physical activity), group C (15 sedentary BC survivors), group D (10 healthy subjects, participating in recreational physical activity) and group E (10 sedentary healthy subjects). ELISA assays revealed a significant increase in the level of circulating MMP-2 in group B compared with all other groups. Recreational physical activity increased the levels of MMP-9 in healthy subjects (group D vs. E), however, the differences were not statistically significant, while in the BC survivor groups the results were opposite, with exercise reducing MMP-9 levels (group B vs. C). Furthermore, a significant increase in MMP-2 was observed in group B lymph node metastasis-positive (N+) subjects compared with group A and C N+ subjects. Thus, the results of the present study indicate that various physical activities modulate the levels of circulating MMP-2 and -9 in BC survivors, and the same exercise program induces a different effect when undertaken by healthy subjects and BC survivors. These results may have important implications with regard to the selection of appropriate physical activities for BC survivors, leading to improvements to their survival and prevention of recurrence, as well as amelioration of physical function, quality of life and fatigue.

Recreational physical activity and risk of triple negative breast cancer in the California Teachers Study

BACKGROUND

Evidence has accumulated showing that recreational physical activity reduces breast cancer risk. However, it is unclear whether risk reduction pertains to specific receptor-defined subtypes. Moreover, few studies have examined whether changes in the amount of recreational physical activity during adulthood influence breast cancer risk.

METHODS

A total of 108,907 women, ages 22 to 79 years with no history of breast cancer when joining the California Teachers Study in 1995-1996, completed a baseline questionnaire and were eligible for the study. Through 2012, 5882 women were diagnosed with invasive breast cancer. Breast cancer subtypes were defined by the expression status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). Multivariable Cox proportional hazards models provided adjusted hazard ratios (HRs) and 95 % confidence intervals (CIs) for breast cancer overall and ER/PR/HER2-defined subtypes associated with long-term (from high school through age 54 or age at cohort entry, whichever was younger) and baseline (during 3 years prior to baseline) recreational physical activity. Among women who also completed a follow-up questionnaire at 10 years after baseline in 2005-2008 (54,686 women, 1406 with invasive breast cancer), risk associated with changes in the amount of recreational physical activity from baseline to the 10-year follow-up (during 3 years prior to the 10-year follow-up) was determined.

RESULTS

Both long-term and baseline strenuous recreational physical activity were inversely associated with risk of invasive breast cancer (P trend ≤0.03). The observed associations were mainly confined to women with triple negative breast cancer (TNBC, ER-/PR-/HER2-, P trend ≤0.02) or luminal A-like subtype (ER+ or PR+ plus HER2-) who were former users of menopausal hormone therapy at baseline (P trend = 0.02, P homogeneity of trends ≤0.03). Moreover, women who consistently engaged in the highest level (≥3.51 h/wk/y) of strenuous recreational physical activity between baseline and 10-year follow-up had the lowest risk of breast cancer (HR = 0.71, 95 % CI = 0.52-0.98) when compared to those who were consistently low (≤0.50 h/wk/y).

CONCLUSIONS

Strenuous recreational physical activity is associated with lower breast cancer risk, especially TNBC. The benefit may be maximized by consistently engaging in high-intensity recreational physical activity during adulthood.

Association of Leisure-Time Physical Activity With Risk of 26 Types of Cancer in 1.44 Million Adults

IMPORTANCE

Leisure-time physical activity has been associated with lower risk of heart-disease and all-cause mortality, but its association with risk of cancer is not well understood.

OBJECTIVE

To determine the association of leisure-time physical activity with incidence of common types of cancer and whether associations vary by body size and/or smoking.

DESIGN, SETTING, AND PARTICIPANTS

We pooled data from 12 prospective US and European cohorts with self-reported physical activity (baseline, 1987-2004). We used multivariable Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals for associations of leisure-time physical activity with incidence of 26 types of cancer. Leisure-time physical activity levels were modeled as cohort-specific percentiles on a continuous basis and cohort-specific results were synthesized by random-effects meta-analysis. Hazard ratios for high vs low levels of activity are based on a comparison of risk at the 90th vs 10th percentiles of activity. The data analysis was performed from January 1, 2014, to June 1, 2015.

EXPOSURES

Leisure-time physical activity of a moderate to vigorous intensity.

MAIN OUTCOMES AND MEASURES

Incident cancer during follow-up.

RESULTS

A total of 1.44 million participants (median [range] age, 59 [19-98] years; 57% female) and 186 932 cancers were included. High vs low levels of leisure-time physical activity were associated with lower risks of 13 cancers: esophageal adenocarcinoma (HR, 0.58; 95% CI, 0.37-0.89), liver (HR, 0.73; 95% CI, 0.55-0.98), lung (HR, 0.74; 95% CI, 0.71-0.77), kidney (HR, 0.77; 95% CI, 0.70-0.85), gastric cardia (HR, 0.78; 95% CI, 0.64-0.95), endometrial (HR, 0.79; 95% CI, 0.68-0.92), myeloid leukemia (HR, 0.80; 95% CI, 0.70-0.92), myeloma (HR, 0.83; 95% CI, 0.72-0.95), colon (HR, 0.84; 95% CI, 0.77-0.91), head and neck (HR, 0.85; 95% CI, 0.78-0.93), rectal (HR, 0.87; 95% CI, 0.80-0.95), bladder (HR, 0.87; 95% CI, 0.82-0.92), and breast (HR, 0.90; 95% CI, 0.87-0.93). Body mass index adjustment modestly attenuated associations for several cancers, but 10 of 13 inverse associations remained statistically significant after this adjustment. Leisure-time physical activity was associated with higher risks of malignant melanoma (HR, 1.27; 95% CI, 1.16-1.40) and prostate cancer (HR, 1.05; 95% CI, 1.03-1.08). Associations were generally similar between overweight/obese and normal-weight individuals. Smoking status modified the association for lung cancer but not other smoking-related cancers.

CONCLUSIONS AND RELEVANCE

Leisure-time physical activity was associated with lower risks of many cancer types. Health care professionals counseling inactive adults should emphasize that most of these associations were evident regardless of body size or smoking history, supporting broad generalizability of findings.

Physical activity, hormone replacement therapy and breast cancer risk: A meta-analysis of prospective studies

BACKGROUND

Lower risk of breast cancer has been reported among physically active women, but the risk in women using hormone replacement therapy (HRT) appears to be higher. We quantified the association between physical activity and breast cancer, and we examined the influence that HRT use and other risk factors had on this association.

METHODS

After a systematic literature search, prospective studies were meta-analysed using random-effect models applied on highest versus lowest level of physical activity. Dose-response analyses were conducted with studies reporting physical activity either in hours per week or in hours of metabolic equivalent per week (MET-h/week).

RESULTS

The literature search identified 38 independent prospective studies published between 1987 and 2014 that included 116,304 breast cancer cases. Compared to the lowest level of physical activity, the highest level was associated with a summary relative risk (SRR) of 0.88 (95% confidence interval [CI] 0.85, 0.90) for all breast cancer, 0.89 (95% CI 0.83, 0.95) for ER+/PR+ breast cancer and 0.80 (95% CI 0.69, 0.92) for ER-/PR- breast cancer. Risk reductions were not influenced by the type of physical activity (occupational or non-occupational), adiposity, and menopausal status. Risk reductions increased with increasing amounts of physical activity without threshold effect. In six studies, the SRR was 0.78 (95% CI 0.70, 0.87) in women who never used HRT and 0.97 (95% CI 0.88, 1.07) in women who ever used HRT, without heterogeneity in results. Findings indicate that a physically inactive women engaging in at least 150 min per week of vigorous physical activity would reduce their lifetime risk of breast cancer by 9%, a reduction that might be two times greater in women who never used HRT.

CONCLUSION

Increasing physical activity is associated with meaningful reductions in the risk of breast cancer, but in women who ever used HRT, the preventative effect of physical activity seems to be cancelled out.