Physical activity and breast cancer risk: impact of timing, type and dose of activity and population subgroup effects

Does obesity modify the relationship between physical activity and breast cancer risk?

PURPOSE

With only 5-10% of breast cancer cases attributed to genetic inheritance, prevention efforts have focused on modifiable risk factors. Physical activity plays a role in reducing breast cancer risk; however, the interaction between physical activity and other modifiable risk factors, such as obesity, has received little attention.

METHODS

A systematic review and meta-analysis was conducted of studies examining the relationship between physical activity and breast cancer and how it may be modified by body mass index (BMI).

RESULTS

A total of 29 papers were included: 18 were cohort and 11 were case-control studies. Overall, a significant reduction in the relative risk of breast cancer was found in postmenopausal women with high versus low levels of physical activity for women with a BMI <25 kg/m² (RR 0.85, 95% CI 0.79, 0.92) and ≥25 kg/m² (RR 0.87, 95% CI 0.81, 0.93) but not ≥30 kg/m² (RR: 0.93, 95% CI 0.76, 1.13). Physical activity was not associated with a significant reduction in risk of breast cancer in premenopausal women in any BMI group.

CONCLUSION

The results of this meta-analysis suggest that physical activity is associated with a larger breast cancer risk reduction among women who are normal weight or overweight than among women who are obese. Since the included studies used diverse methods for assessment of physical activity and categories of BMI, results should be interpreted with caution and additional work is needed.

Breast Cancer Epidemiology in Gulf Cooperation Council Countries: A Regional and International Comparison

Breast cancer is the most frequently diagnosed noncutaneous malignancy in women living in Gulf Cooperation Council countries. The present report aimed to highlight the similarities and variations in breast cancer incidence, age at diagnosis, clinicopathologic features, molecular characteristics, and lifestyle factors that contribute to an increasing incidence of breast cancer compared with neighboring Arab and westernized countries. The data presented, although having important implications for policy makers, also highlights the need for further research. Such research would ensure that effective prevention and detection strategies are tailored to the specific needs of the Gulf women such that the management of breast cancer is optimized.

Relationship between physical activity practice and metabolic profile of postmenopausal women under treatment with aromatase inhibitors for breast cancer

OBJECTIVE

To analyze the relationship between physical activity practice and metabolic profile of postmenopausal women under treatment with aromatase inhibitors (AIs) for the treatment of breast cancer.

STUDY DESIGN

Cross-sectional study, conducted with 101 postmenopausal women (aged 50-80 years). The sample was divided into two groups; group without cancer (GW; n=65) and breast cancer group treated with AIs (GC; n=36). Physical activity (PA) was evaluated by questionnaire. Correlations between physical activity and metabolic variables were made by Pearson's correlation coefficient and the magnitude of these relationships by linear regression.

RESULTS

In GW, there were observed significant inverse correlations between physical activity and VLDL cholesterol (β=-0.036; 95% CI=-0.068; -0.004); triglycerides (β=-0.036; 95% CI=-0.015; -0.002); glycose (β=-0.029; 95% CI=-0.047; -0.012); and C-reactive protein (β=-0.44; 95% CI=-0.085; -0.003). However, for women under treatment of AIs there was no relationship between physical activity and metabolic variables.

CONCLUSION

The amount of physical activity practice is inversely related to lipid profile, glucose and C-reactive protein in women without breast cancer. This relation was not observed in the cancer survivors, suggesting that the use of aromatase inhibitors could influence or low intensity of physical activity.

Cost-Effectiveness of a Community Exercise and Nutrition Program for Older Adults: Texercise Select

The wide-spread dissemination of evidence-based programs that can improve health outcomes among older populations often requires an understanding of factors influencing community adoption of such programs. One such program is Texercise Select, a community-based health promotion program previously shown to improve functional health, physical activity, nutritional habits and quality of the life among older adults. This paper assesses the cost-effectiveness of Texercise Select in the context of supportive environments to facilitate its delivery and statewide sustainability. Participants were surveyed using self-reported instruments distributed at program baseline and conclusion. Program costs were based on actual direct costs of program implementation and included costs of recruitment and outreach, personnel costs and participant incentives. Program effectiveness was measured using quality-adjusted life year (QALY) gained, as well as health outcomes, such as healthy days, weekly physical activity and Timed Up-and-Go (TUG) test scores. Preference-based EuroQol (EQ-5D) scores were estimated from the number of healthy days reported by participants and converted into QALYs. There was a significant increase in the number of healthy days (p < 0.05) over the 12-week program. Cost-effectiveness ratios ranged from $1374 to $1452 per QALY gained. The reported cost-effective ratios are well within the common cost-effectiveness threshold of $50,000 for a gained QALY. Some sociodemographic differences were also observed in program impact and cost. Non-Hispanic whites experienced significant improvements in healthy days from baseline to the follow-up period and had higher cost-effectiveness ratios. Results indicate that the Texercise Select program is a cost-effective strategy for increasing physical activity and improving healthy dietary practices among older adults as compared to similar health promotion interventions. In line with the significant improvement in healthy days, physical activity and nutrition-related outcomes among participants, this study supports the use of Texercise Select as an intervention with substantial health and cost benefits.

Breast cancer relatives' physical activity intervention needs and preferences: qualitative results

Background

While many risk factors for breast cancer, such as family history, are not modifiable, some, however, can be modified. The study used formative qualitative research to learn about the physical activity intervention preferences and needs of first-degree female relatives (FDFRs) of breast cancer patients; that information was then used to develop a targeted physical activity intervention.

Methods

Twenty FDFRs first completed a 12-week physical activity intervention and then attended two sequential focus groups (7 groups total). In the first set of focus groups participants provided feedback on the intervention. In the follow-up focus groups, proposed changes based on collected responses from the first groups were presented and participants provided feedback to further refine the intervention.

Results

Overall, we found strong interest for an intervention using breast cancer-related health concerns to promote positive behavior change. A theme underlying all of the feedback was the desire for a personalized intervention that was directly relevant to their lives. Participants wanted this personalization achieved through individually tailored content and incorporation of stories from other FDFRs. In order to successfully use concerns about breast cancer to motivate behavior change, participants also wanted a discussion about their individual risk factors for breast cancer including, but not limited to, lack of physical activity.

Conclusions

This study demonstrates women’s interest in receiving personalized information and highlights specific ways to individualize an intervention that increases motivation and engagement. Using a sequential qualitative approach was effective for formative intervention development.

Trial registration number

NCT03115658 (Retrospectively registered 4/13/17).

Physical Exercise Positively Influences Breast Cancer Evolution

Breast cancer is one of the most commonly diagnosed types of cancer in women. Its pathogenesis involves genetic, hormonal, and environmental factors. A large body of evidence indicates that physical activity has positive effects on every aspect of breast cancer evolution, including prevention, medical treatment, and aftercare clinical settings. Thus, different types of exercise can influence the prevention and progression of the disease through several common mechanisms, such as reduction of insulin resistance and improvement of immunity and cardiovascular function. Furthermore, acute and chronic symptoms of breast cancer, such as cachexia, muscle mass loss, fatigue, cardiotoxicity, weight gain, hormone alterations, bone loss, and psychologic adverse effects, may all be favorably influenced by regular exercise. We review the relation of intensity and duration of exercise with potential pathophysiologic pathways, including obesity-related hormones and sex steroid hormone production, oxidative stress, epigenetic alterations such as DNA hypomethylation, and changes in telomere length, within the context of the beneficial effects of exercise. The potential role of exercise in reducing the intensity of the adverse effects that result from breast cancer and anticancer treatment is also discussed.

Cancer incidence attributable to inadequate physical activity in Alberta in 2012

BACKGROUND

Physical inactivity has been consistently associated with increased risk of colorectal, endometrial, breast (in postmenopausal women), prostate, lung and ovarian cancers. The objective of the current analysis was to estimate the proportion and absolute number of site-specific cancer cases attributable to inadequate physical activity in Alberta in 2012.

METHODS

We used population attributable risks to estimate the proportion of each site-specific cancer attributable to inactivity. Relative risk estimates were obtained from the epidemiological literature, and prevalence estimates were calculated with the use of data from the Canadian Community Health Survey cycle 2.1 (2003). Respondents who acquired 1.5-2.9 kcal/kg per day and less than 1.5 kcal/kg per day of physical activity were classified as moderately active and inactive, respectively, and both levels were considered inadequate for mitigating cancer risks. We obtained age-, sex- and site-specific cancer incidence data from the Alberta Cancer Registry for 2012.

RESULTS

About 59%-75% of men and 69%-78% of women did not engage in adequate physical activity. Overall, 13.8% of cancers across all associated cancers were estimated to be attributable to inadequate physical activity, representing 7.2% of all cancers diagnosed in Alberta in 2012. Suboptimal levels of physical activity had a greater impact among women: the proportion of all associated cancers attributable to inadequate physical activity was 18.3% for women and 9.9% for men.

INTERPRETATION

A substantial proportion of cancer cases diagnosed in Alberta were estimated to be attributable to inadequate physical activity. With the high prevalence of physical inactivity among adults in the province, developing strategies to increase physical activity levels could have a notable impact on reducing future cancer burden in Alberta.

Exercise and Sports Medicine Issues in Underserved Populations

Primary care providers can make a strong argument for exercise promotion in underserved communities. The benefits are vitally important in adolescent physical, cognitive, and psychological development as well as in adult disease prevention and treatment. In counseling such patients, we should take into account a patient's readiness for change and the barriers to exercise.

The Mechanisms and Effects of Physical Activity on Breast Cancer

Breast cancer is the most common cancer in women. An extensive part of this health problem can be prevented by an active lifestyle. Physical activity can reduce the risk of breast cancer, reduce the rate of recurrence, and increase the survival rate of patients with breast cancer. The aim of this review was to summarize our current knowledge regarding the effects of physical activity on breast cancer risk, recurrence, and survival. Furthermore, we investigated 5 possible underlying mechanisms through which physical activity has an influence on breast cancer (ie, a reduction of sex hormones, metabolic hormones, adipokines and oxidative stress, and an improvement of the immune function). In this review, we give a complete overview of this subject.

Psychosocial Variables Related to Why Women are Less Active than Men and Related Health Implications

This article reviews psychosocial influences on women’s participation in physical activity as they differ from men and how associated activity differences impact women’s risk for a number of chronic diseases. This topic directly aligns with the mission of this special edition related to disparities in women’s health as the typically lower level of physical activity in females directly impacts their health. On average, females participate in physical activity at lower rates than their male counterparts. These lower rates of physical activity are directly related to both incidence of and outcomes from cardiovascular disease, type 2 diabetes, and breast and gynecological cancers. The relationship between psychosocial factors that are understood to affect physical activity differs between men and women. Specifically, self-efficacy, social support, and motivation are empirically substantiated factors that found to impact physical activity participation among women differently than men. Understanding these relationships is integral to designing effective interventions to target physical activity participation in women so that the related health risks are adequately addressed.

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.

Getting the SCOOP-Survey of Cardiovascular Outcomes From Oncology Patients During Survivorship

BACKGROUND

Cardiovascular (CV) disease is the second most common cause of mortality and morbidity in cancer survivors (CS). Limited data exist on the knowledge and awareness of CS about CV effects of cancer therapies and its effect on lifestyle of survivors. It is important to identify gaps in CV care of CS.

MATERIALS AND METHODS

A brief voluntary, anonymous, web-based questionnaire was designed to assess the awareness of CS about the interaction between CV disease, CV symptoms and lifestyle changes from cancer treatment.

RESULTS

A total of 213 volunteers (181 women) with mean age of 56 years responded to the survey. Breast cancer was the most prevalent cancer diagnosis. In all, 15% reported CV disease before therapy with a higher incidence of CV disease in survivors more than 5 years from diagnosis (20% >5 years versus 10% <5 years of survivorship, P = 0.05). The reported use of beta blockers (9%) and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (9%) was rare despite the high incidence of CV disease. Only one-fourth of survivors were offered CV screening during treatment, whereas 36% of survivors had unanswered questions about CV symptoms from therapy. The CV symptoms adversely affected lifestyle in 27% of CS. One-fifth of survivors received exercise counseling even though half would have liked counseling.

CONCLUSIONS

The survey demonstrates that CS have self-reported CV symptoms and there may be unmet needs for CV preventive services. Further work is needed to develop collaborative patient counseling and management strategies between oncology and cardiology for improving CV health and symptoms of CS.

Potential breast cancer risk factors among Saudi women aged 19-50 years in Jeddah: a case-control study

BACKGROUND AND OBJECTIVES

The Saudi cancer registry reported in 2009 that the frequency of breast cancer is the highest among all types of cancer among Saudi women aged 30-59 years. The Makkah region had the second highest frequency of reported breast cancer cases, with patients having a median age of 46 years. The objectives of this study were to explore the distribution of selected known and hypothetically claimed breast cancer risk factors among Saudi women aged 19-50 years and describe the association of breast cancer with selected risk factors.

DESIGN AND SETTING

An unmatched case-control study was conducted on breast cancer cases at three different hospitals in Jeddah.

PATIENTS AND METHODS

Online OpenEpi was used and the method of Kelsey and colleagues was selected from OpenEpi output; the calculated number of cases and controls was 134 each. Women aged 19-50 years were included and the analysis was conducted on 151 cases and 166 controls as they met the age inclusion criteria.

RESULTS

The mean age of patients was 40 years. A subgroup analysis for age at menarche less than 12 years showed an odds ratio (OR) of 1.4 6 [95% confidence interval (CI) 0.88-2.44]. A high proportion of cases reported the use of exogenous estrogen and progesterone (OR=4.7, 95% CI 1.7-13.0), previous mammography screening (89% of cases vs. 11% of controls), and affected family members (4.6 vs. 1.8, OR=2.64 [95% CI 0.67-10.4]. The OR for exercise frequency in the study group was 1.45 (95% CI 0.90-2.35). The OR for breastfeeding among mothers who breast-fed for more than 12 months was 0.56 (95% CI 0.35-0.88).

CONCLUSION AND RECOMMENDATIONS

This study provides information on associative factors such as early age at menarche (<12 years), monthly income of at least 20 000 SR (5333 USD), use of exogenous estrogen and progesterone, previous biopsies/surgeries, previous clinical breast examination and mammography screening, and affected family members. Protective factors among premenopausal women, such as breastfeeding and exercising, have been described. Conducting comprehensive sessions on breastfeeding and physical education targeting young generations is highly recommended in order to reduce the risk for breast cancer among Saudi women aged 19-50 years.

Rationale, design, and baseline findings from HIPP: A randomized controlled trial testing a home-based, individually-tailored physical activity print intervention for African American women in the Deep South

African American women report high rates of physical inactivity and related health disparities. In our previous formative research, we conducted a series of qualitative assessments to examine physical activity barriers and intervention preferences among African American women in the Deep South. These data were used to inform a 12-month Home-based, Individually-tailored Physical activity Print (HIPP) intervention, which is currently being evaluated against a wellness contact control condition among 84 post-menopausal African American women residing in the metropolitan area of Birmingham, Alabama. This paper reports the rationale, design and baseline findings of the HIPP trial. The accrued participants had an average age of 57 (SD=4.7), a BMI of 32.1 kg/m(2) (SD=5.16) with more than half (55%) having a college education and an annual household income under $50,000 (53.6%). At baseline, participants reported an average of 41.5 min/week (SD=49.7) of moderate intensity physical activity, and 94.1% were in the contemplation or preparation stages of readiness for physical activity. While social support for exercise from friends and family was low, baseline levels of self-efficacy, cognitive and behavioral processes of change, decisional balance, outcome expectations, and enjoyment appeared promising. Baseline data indicated high rates of obesity and low levels of physical activity, providing strong evidence of need for intervention. Moreover, scores on psychosocial measures suggested that such efforts may be well received. This line of research in technology-based approaches for promoting physical activity in African American women in the Deep South has great potential to address health disparities and impact public health.

Lifetime physical activity and the risk of non-Hodgkin lymphoma

Research regarding the association between physical activity and the risk of non-Hodgkin lymphoma (NHL) is limited and inconsistent, and few studies have investigated whether the intensity and timing of physical activity influence the association. A case-control study of NHL was conducted in British Columbia, Canada, in 2000 to 2004. Data were collected on various NHL risk factors, including moderate-intensity and vigorous-intensity physical activity performed over the lifetime. Logistic regression was used to estimate the association between physical activity and the risk of NHL. This analysis included 818 controls and 749 cases. Lifetime vigorous-intensity physical activity was inversely associated with NHL risk. Participants in the second, third, and fourth quartiles of lifetime vigorous-intensity physical activity had an approximately 25% to 30% lower risk of NHL than those in the lowest quartile [adjusted odds ratios, 0.69 (95% confidence interval [CI], 0.52-0.93); 0.68 (95% CI, 0.50-0.92); and 0.75 (95% CI, 0.55-1.01), respectively]. No consistent associations were observed for total or moderate-intensity physical activity. There were no apparent age periods in which physical activity appeared to confer a greater risk reduction. In this study, we found that lifetime vigorous-intensity physical activity was associated with a significantly reduced risk of NHL. Given this finding, more research on physical activity intensity and timing in relation to NHL risk is warranted.

Is preoperative physical activity related to post-surgery recovery? A cohort study of patients with breast cancer

OBJECTIVE

The aim of our study is to assess the association between preoperative level of activity and recovery after breast cancer surgery measured as hospital stay, length of sick leave and self-assessed physical and mental recovery.

DESIGN

A prospective cohort study.

SETTING

Patients included were those scheduled to undergo breast cancer surgery, between February and November 2013, at two participating hospitals in the Western Region of Sweden.

PARTICIPANTS

Patients planned for breast cancer surgery filled out a questionnaire before, as well as at 3 and 6 weeks after the operation. The preoperative level of activity was self-assessed and categorised into four categories by the participants using the 4-level Saltin-Grimby Physical Activity Level Scale (SGPALS).

MAIN OUTCOME MEASURE

Our main outcome was postoperative recovery measured as length of sick leave, in-hospital stay and self-assessed physical and mental recovery.

RESULTS

220 patients were included. Preoperatively, 14% (31/220) of participants assessed themselves to be physically inactive, 61% (135/220) to exert some light physical activity (PA) and 20% (43/220) to be more active (level 3+4). Patients operated with mastectomy versus partial mastectomy and axillary lymph node dissection versus sentinel node biopsy were less likely to have a short hospital stay, relative risk (RR) 0.88 (0.78 to 1.00) and 0.82 (0.70 to 0.96). More active participants (level 3 or 4) had an 85% increased chance of feeling physically recovered at 3 weeks after the operation, RR 1.85 (1.20 to 2.85). No difference was seen after 6 weeks.

CONCLUSIONS

The above study shows that a higher preoperative level of PA is associated with a faster physical recovery as reported by the patients 3 weeks post breast cancer surgery. After 6 weeks, most patients felt physically recovered, diminishing the association above. No difference was seen in length of sick leave or self-assessed mental recovery between inactive or more active patients.

Physical Activity and Risk of Male Breast Cancer

The association between leisure-time physical activity (LTPA) and male breast cancer risk is unclear. In the Male Breast Cancer Pooling Project, with 449 cases and 13,855 matched controls, we used logistic regression with study stratification to generate adjusted ORs and 95% confidence intervals (CI) for LTPA tertiles and male breast cancer risk. Compared with low LTPA, medium and high LTPA were not associated with male breast cancer risk (OR, 1.01; 95% CI, 0.79-1.29; 0.90, 0.69-1.18, respectively). In joint-effects analyses, compared with the referent of high body mass index (BMI; ≥25 kg/m(2))/low LTPA, neither medium nor high PA was associated with risk among high BMI men, but normal BMI men (<25 kg/m(2)) with low or medium LTPA were at a nonsignificant ∼16% reduced risk and those with high LTPA were at a 27% reduced risk (OR, 0.73; 95% CI, 0.50-1.07). Physical activity alone may not confer protection against male breast cancer risk.

Rationale and design of the Adapted Physical Activity in advanced Pancreatic Cancer patients (APACaP) GERCOR (Groupe Coopérateur Multidisciplinaire en Oncologie) trial: study protocol for a randomized controlled trial

BACKGROUND

Exercise during chemotherapy is a promising strategy to reduce fatigue and improve health-related quality of life (HRQoL). It has been shown to be feasible and efficient in various cancers, including advanced-stage cancers. Effects of physical activity have never been explored in advanced pancreatic ductal adenocarcinoma (PDAC). We aim to evaluate the effects of an exercise intervention in this setting.

METHODS

This randomized, national, multicenter, interventional study will examine the effectiveness of an unsupervised, home-based, 16-week adapted physical activity (APA) program. Specificities of advanced PDAC for the implementation of the APA program will be taken into account (healthy volunteer as physical activity partner instead of patient groups, nutritional management). The main inclusion criteria are: patients with histologically confirmed, unresectable PDAC; scheduled for chemotherapy; performance status 0-2; age ≥ 18; and physical activity partner. In total, 200 patients will be randomized into either the APA program (aerobic and resistance exercises) in addition to usual care (including chemotherapy at the investigator's choice), or usual care. The primary objective will be the effect on fatigue (Multidimensional Fatigue Inventory, MFI-20) and HRQoL (European Organization for Research and Treatment of Cancer-Quality of Life-C30 questionnaire, EORTC-QLQ-C30; co-primary endpoint) at week 16. As secondary objectives, the effects of the exercise intervention on pain, anxiety, depression, nutritional status, insulin resistance, tolerance of chemotherapy, survival, and adherence to the APA program will be evaluated.

DISCUSSION

Patients with advanced PDAC are strongly affected by fatigue, and are thus likely to benefit from an exercise intervention. Moreover, exercise may have a potential beneficial effect on tumor outcome by reducing insulin resistance and insulin/insulin-like growth factor-1 (IGF-1) secretion. However, an exercise intervention may appear challenging due to multiple PDAC-related symptoms such as fatigue, depression, pain, and denutrition. We hypothesize that an APA program taking into account specific characteristics of PDAC may improve symptoms and HRQoL. If demonstrated to be feasible and effective, such APA programs will be systematically proposed to patients with advanced PDAC in addition to usual care.

TRIAL REGISTRATION

ClinicalTrial.gov

REGISTRATION NUMBER

NCT02184663 ; Registration date: 2 July 2014.

A prospective study of occupational physical activity and breast cancer risk

PURPOSE

Physical activity has been associated with reduced breast cancer risk, but studies of occupational activity have produced inconsistent results. The purpose of this study was to evaluate the relationship between occupational physical activity and breast cancer in a prospective study of women with a family history of breast cancer.

METHODS

We studied breast cancer risk in 47,649 Sister Study participants with an occupational history. Information on occupational activity and breast cancer risk factors was collected during baseline interviews (2004-2009). Physical activity at each job was self-reported and categorized as mostly sitting, sitting and standing equally, mostly standing, and active. Multivariable Cox proportional hazards regression was used to evaluate associations between lifetime occupational activity and incident breast cancer, after adjusting for established risk factors and recreational activity.

RESULTS

During follow-up, a total of 1,798 breast cancer diagnoses were reported. Compared with women who did not spend any time in active jobs, women who spent a high proportion (≥75%) of their working years in active jobs had a reduced risk of breast cancer (HR 0.72; 95% CI 0.52-0.98). Associations were strongest among overweight (HR 0.64; 95% CI 0.42-0.98) and postmenopausal (HR 0.67; 95% CI 0.45-0.98) women.

CONCLUSIONS

Occupational activity was associated with a reduced risk of breast cancer. Occupational activity is a domain of physical activity that should be further examined in studies of postmenopausal breast cancer risk. Additional research is necessary to better understand the mechanisms underlying the relationships between occupational activity, body size, and breast cancer.

Correlation of Physical Activities and Breast Cancer Characteristics: A Prospective Analysis with Special Focus on Triple Negative Breast Cancer

OBJECTIVE

Several studies have demonstrated that daily physical activity (PA) prevents the development of breast cancer. Our objective was to examine the relationship between PA and clinical and biological tumor characteristics in breast cancer patients in order to determine the impact of energy expenditure (EE) on tumor prognosis.

METHODS

We pooled data from two prospective studies, including a total of 121 breast cancer patients. The measure of PA was done using the self-completion Population Physical Activity Questionnaire, which was answered by each patient.

RESULTS

Ten patients harbored triple negative (TN) tumors. The mean body mass index (BMI) in the general population and in patients with TN tumors was 24.3 and 25.6, respectively. The mean daily EE (DEE) was 10,266 kJ×24 h(-1) in the general population and 11,212 kJ×24 h(-1) in patients with TN tumors. In the whole population, there was an inverse statistical correlation between BMI and DEE, rest, low PA, and high PA (p=0.0002, p=0.003, p<0001, and p=0.03, respectively). There was a positive correlation between negative estrogen receptor status and intensive PA (p=0.041) and DEE (p=0.007). For TN tumors, there was no significant correlation between BMI and categories of EE.

CONCLUSIONS

Lifestyle (weight regulation, PA) should be adapted and personalized according to biological, clinical, and epidemiological characteristics of the tumors.

The effect of physical training on the N-methyl-N-nitrosourea-induced mammary carcinogenesis of Sprague-Dawley rats

The impact of physical activity on carcinogenesis has been demonstrated in many studies. Taking into account the discrepant results of physical exercise on the cell proliferation and apoptosis of breast cancer, we aimed to examine the impact of physical training on N-methyl-N-nitrosourea-(MNU)-induced mammary carcinogenesis. Fifty female rats were divided into four groups according to the intensity of physical activity they undertook. The number of developed tumors, tumor volume, and histopathological diagnoses were noted. Apoptosis and cell proliferation were studied by the number of TUNEL-positive and Ki-67-expressing cells. We demonstrated a statistically significant decrease in the tumor number between all trained groups and the control group. The results were most pronounced in the group with a moderate intensity of training. Moreover, we showed a decrease in tumor volume as training intensity increased, though the differences were not statistically significant. The mean number of TUNEL-positive cancer cells was significantly higher in the training groups than in the control group. These data suggest that physical training, especially of moderate intensity, may alleviate MNU-induced mammary carcinogenesis. The results could suggest that physical exercise-induced apoptosis may be a protective mechanism.

Reduced risk of breast cancer associated with recreational physical activity varies by HER2 status

Convincing epidemiologic evidence indicates that physical activity is inversely associated with breast cancer risk. Whether this association varies by the tumor protein expression status of the estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), or p53 is unclear. We evaluated the effects of recreational physical activity on risk of invasive breast cancer classified by the four biomarkers, fitting multivariable unconditional logistic regression models to data from 1195 case and 2012 control participants in the population-based Women’s Contraceptive and Reproductive Experiences Study. Self-reported recreational physical activity at different life periods was measured as average annual metabolic equivalents of energy expenditure [MET]-hours per week. Our biomarker-specific analyses showed that lifetime recreational physical activity was negatively associated with the risks of ER-positive (ER+) and of HER2-negative (HER2−) subtypes (both P_trend ≤ 0.04), but not with other subtypes (all P_trend > 0.10). Analyses using combinations of biomarkers indicated that risk of invasive breast cancer varied only by HER2 status. Risk of HER2–breast cancer decreased with increasing number of MET-hours of recreational physical activity in each specific life period examined, although some trend tests were only marginally statistically significant (all P_trend ≤ 0.06). The test for homogeneity of trends (HER2– vs. HER2+ ) reached statistical significance only when evaluating physical activity during the first 10 years after menarche (P_homogeneity = 0.03). Our data suggest that physical activity reduces risk of invasive breast cancers that lack HER2 overexpression, increasing our understanding of the biological mechanisms by which physical activity acts.

Background risk of breast cancer and the association between physical activity and mammographic density

INTRODUCTION

High physical activity has been shown to decrease the risk of breast cancer, potentially by a mechanism that also reduces mammographic density. We tested the hypothesis that the risk of developing breast cancer in the next 10 years according to the Tyrer-Cuzick prediction model influences the association between physical activity and mammographic density.

METHODS

We conducted a population-based cross-sectional study of 38,913 Swedish women aged 40-74 years. Physical activity was assessed using the validated web-questionnaire Active-Q and mammographic density was measured by the fully automated volumetric Volpara method. The 10-year risk of breast cancer was estimated using the Tyrer-Cuzick (TC) prediction model. Linear regression analyses were performed to assess the association between physical activity and volumetric mammographic density and the potential interaction with the TC breast cancer risk.

RESULTS

Overall, high physical activity was associated with lower absolute dense volume. As compared to women with the lowest total activity level (<40 metabolic equivalent hours [MET-h] per day), women with the highest total activity level (≥50 MET-h/day) had an estimated 3.4 cm(3) (95% confidence interval, 2.3-4.7) lower absolute dense volume. The inverse association was seen for any type of physical activity among women with <3.0% TC 10-year risk, but only for total and vigorous activities among women with 3.0-4.9% TC risk, and only for vigorous activity among women with ≥5.0% TC risk. The association between total activity and absolute dense volume was modified by the TC breast cancer risk (P interaction = 0.05). As anticipated, high physical activity was also associated with lower non-dense volume. No consistent association was found between physical activity and percent dense volume.

CONCLUSIONS

Our results suggest that physical activity may decrease breast cancer risk through reducing mammographic density, and that the physical activity needed to reduce mammographic density may depend on background risk of breast cancer.

Walking, biking or sport: how Spanish women attending breast cancer screening meet physical activity recommendations?

BACKGROUND

The aim is to analyse physical activity (PA), the fulfillment recommendation of at least 150 min of moderate PA, through walking/biking (W&B), sport, both types of PA and the factors associated with inactivity by Spanish women who attended breast cancer screening programmes.

METHODS

The DDM-Spain is a multicentre cross-sectional study involving 3584 women, aged 45-68, attending screening in seven Spanish cities. Data were collected using a questionnaire, including age, socio-demographic and lifestyle characteristics, family burden and PA. PA was converted into metabolic equivalent of task (METs), categorized as low ≤ 600 METs min per week (m/w), moderate 600-3000 METs m/w and high ≥ 3000 METs m/w. A multivariate logistic regression was performed to identify variables associated with inactivity for each type of PA.

RESULTS

No women achieved a high level of PA through sport. 79.2% achieved a high or moderate level of PA by W&B. Lack of sport was associated with being overweight (odds ratio OR = 1.31; 95% confidence interval CI: 1.06 to 1.62), body mass index (BMI) ≥ 30 (OR = 1.85; 95% CI: 1.44 to 2.38), smoking (OR = 1.56; 95% CI: 1.22 to 2.00) and living with a disabled person (OR = 1.64; 95% CI: 1.0 to 2.81), whereas enough sport practice was associated with higher educational or socio-economic level (SEL). Regarding W&B, inactivity was associated with BMI ≥ 30 (OR = 1.91; 95% CI: 1.49 to 2.45) and living with someone >74 (OR = 1.96; 95% CI: 1.48 to 2.58). Inactivity for both types of exercise was associated with a BMI ≥ 30 (OR = 2.13; 95% CI: 1.63 to 2.8), smoking (OR = 1.41; 95% CI: 1.09 to 1.81) and living with someone >74 (OR = 1.69; 95% CI: 1.24 to 2.28).

CONCLUSIONS

Family burden and BMI ≥ 30 are inversely associated with both types of PA. W&B is the most common type of PA regardless of educational and SEL.

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

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

Oncologist perspectives on breast cancer screening in India- results from a qualitative study in Andhra Pradesh

BACKGROUND

It is important to understand the perceptions of oncologists to understand the comprehensive picture of clinical presentation of breast cancer. In the absence of clear evidence, clinical practice involving patients of breast cancer in India should provide insights into stages of breast cancer with which women present to their clinics and mode of screening of breast cancer prevalent in Andhra Pradesh.

MATERIALS AND METHODS

A qualitative study was conducted to understand the perceptions of oncologists regarding clinical presentation of breast cancer, stages at which women present to clinics, and mode of screening of breast cancer prevalent in Andhra Pradesh. In-depth interviews (IDI) were conducted with ten practising oncologists from various public and private cancer hospitals in Hyderabad city to understand their perspectives on breast cancer and screening. The data were triangulated to draw inferences suitable for the current public Health scenario.

RESULTS

Late presentation was indicated as the most important cause of decreased survival among women. Most women present at Stage 3 and 4 when there is no opportunity for surgical intervention. The results indicate that there is a huge gap in awareness about breast cancer, especially in rural areas and among poor socioeconomic groups. Even despite knowledge, most women delay in reporting due to reasons like fear, embarrassment, cost, ignorance, negligence, and easy going attitude.

CONCLUSIONS

It is important to improve awareness about breast cancer and screening methods for promoting early screening. The study inferred that it would be beneficial to establish cancer registries in rural areas. Also, the policymakers need to make key decisions which among three methods (breast self examination (BSE), clinical breast examination and mammography) can best be used as a screening tool and how to successfully implement population wide screening program to prevent mortality and morbidity from breast cancer in India.

The role of body size and physical activity on the risk of breast cancer in BRCA mutation carriers

Women who inherit a BRCA mutation face a high lifetime risk of developing breast cancer. Given the high penetrance of these mutations, prevention is of extreme importance. Here, we review the literature regarding the role of body size and of physical activity in the context of BRCA-associated breast cancer. There is some evidence to support a protective role of a healthy body size and of regular physical activity among mutation carriers, particularly during adolescence or early adulthood. Factors which increase the physiologic expression of the normal copy of the BRCA1 or BRCA2 gene and thereby normalize protein levels, contribute to stem cell homeostasis, and/or affect hormone levels, might mitigate the effects of an inherited BRCA mutation. Preliminary evidence from one in vivo study and from one epidemiologic report suggests that an increase in BRCA1 mRNA expression occurs with increasing levels of physical activity. The prospect of changing lifestyle for the purpose of preventing breast cancer in high-risk women, complemented by mechanistic evidence, warrants evaluation in large-scale prospective studies.

A prospective study of physical activity and breast cancer incidence in African-American women

BACKGROUND

Physical activity has been associated with reduced risk of breast cancer. Evidence on the association in African Americans is limited.

METHODS

With prospective data from the Black Women's Health Study, we assessed vigorous exercise and walking in relation to incidence of invasive breast cancer overall (n = 1,364), estrogen receptor-positive (ER(+), n = 688) cancer, and estrogen receptor-negative (ER(-), n = 405) cancer, based on 307,672 person-years of follow-up of 44,708 African-American women ages 30 years or older at enrollment. Cox proportional hazards models estimated incidence rate ratios (IRR) and 95% confidence intervals (CI).

RESULTS

Vigorous exercise at baseline was inversely associated with overall breast cancer incidence (Ptrend = 0.05): the IRR for ≥7 h/wk relative to <1 h/wk was 0.74 (95% CI, 0.57-0.96). The association did not differ by ER status. Brisk walking for ≥7 h/wk was associated with a reduction similar to that for vigorous exercise. Vigorous exercise at the age of 30 years, 21 years, or in high school was not associated with breast cancer incidence. Sitting for long periods at work or watching TV was not significantly associated with breast cancer incidence.

CONCLUSION

High levels of vigorous exercise or brisk walking may be associated with a reduction in incidence of breast cancer in African-American women.

IMPACT

These results provide informative data on a potential modifiable risk factor, exercise, for breast cancer in African-American women.

Rotating night shift work and physical activity of nurses and midwives in the cross-sectional study in Łódź, Poland

Shift work have been thought to restrict participation in leisure time activities, but the knowledge about physical activity in rotating night shift nurses has been limited so far. We investigated the associations between the rotating night shift work and physical activity using data from a cross-sectional study among nurses and midwives. This study included 354 nurses and midwives (aged 40-60) currently working rotating night shifts and 371 ones working days only. The information on the work characteristics and potential covariates was collected via a personal interview. Weight and height were measured and BMI was calculated. Physical activity was assessed according to the international questionnaire on physical activity - IPAQ, and four domains: leisure time, occupational, transport related and household were analyzed. Women who reported none leisure time activity were defined as recreationally "inactive". The associations were examined with multiple linear or logistic regression models adjusted for age, season of the year, number of full term births, marital status and BMI. Total and occupational physical activity was significantly higher among nurses working rotating night shifts. However, leisure time activity was significantly affected among rotating night shift nurses and midwives, compared to women working during the days only, with increased odds ratio for recreational "inactivity" (OR = 1.57, 95% CI: 1.11-2.20). Rotating night shift work among nurses and midwives is associated with higher occupational physical activity but lower leisure time activity. Initiatives supporting exercising among night shift workers are recommended.

Cancer incidence due to excess body weight and leisure-time physical inactivity in Canada: implications for prevention

OBJECTIVE

This analysis aimed to estimate the number of incident cases of various cancers attributable to excess body weight (overweight, obesity) and leisure-time physical inactivity annually in Canada.

METHODS

The number of attributable cancers was estimated using the population attributable fraction (PAF), risk estimates from recent meta-analyses and population exposure prevalence estimates obtained from the Canadian Community Health Survey (2000). Age-sex-site-specific cancer incidence was obtained from Statistics Canada tables for the most up-to-date year with full national data, 2007. Where the evidence for association has been deemed sufficient, we estimated the number of incident cases of the following cancers attributable to obesity: colon, breast, endometrium, esophagus (adenocarcinomas), gallbladder, pancreas and kidney; and to physical inactivity: colon, breast, endometrium, prostate, lung and/or bronchus, and ovarian.

RESULTS

Overall, estimates of all cancer incidence in 2007 suggest that at least 3.5% (n=5771) and 7.9% (n=12,885) are attributed to excess body weight and physical inactivity respectively. For both risk factors the burden of disease was greater among women than among men.

CONCLUSION

Thousands of incident cases of cancer could be prevented annually in Canada as good evidence exists for effective interventions to reduce these risk factors in the population.

Exercise in patients coping with breast cancer: An overview

Breast cancer is the most common type of cancer in women, but fortunately has high survival rates. Many studies have been performed to investigate the effects of exercise in patients diagnosed with breast cancer. There is evidence that exercise after the diagnosis of breast cancer improves mortality, morbidity, health related quality of life, fatigue, physical functioning, muscle strength, and emotional wellbeing. Based on scientific data, breast cancer patients should be recommended to participate in rehabilitation programs including aerobic and strength training. The aim of this article is to review the recently published data on the effect of exercise in patients with breast cancer in order to present the current perspective on the topic.

Does the population living in Roma settlements differ in physical activity, smoking and alcohol consumption from the majority population in Slovakia?

BACKGROUND

Several studies have revealed a high prevalence of risk factors associated with unhealthy lifestyle among individuals with lower socioeconomic status. In Slovakia, one of the most socially and health-disadvantaged groups is the Roma minority. The aim of this study is to explore differences in physical activity, smoking and alcohol consumption between the population living in Roma settlements and the majority population in Slovakia.

METHODS

Data from the cross-sectional epidemiological HepaMeta study conducted in Slovakia in 2011 were used. The sample consisted of 452 Roma (mean age = 34.7; 35.2% men) and 403 non-Roma (mean age = 33.5; 45.9% men) respondents. The differences in health-related behaviour between the population living in Roma settlements and the majority population were analysed using logistic models separately for males and females.

RESULTS

These data show a clear difference between the population living in Roma settlements and the majority population with regard to leisure-time physical activity (only in women) and smoking, although not alcohol consumption. The prevalence of leisure-time physical activities such as walking or some other type of sport was significantly lower among Roma women than among non-Roma women. Men and women living in Roma settlements are more likely to smoke on a daily basis and they are heavier smokers in comparison with the majority population. HepaMeta study did not find differences in alcohol consumption between the Roma and non-Roma men. However, Roma women reported less frequent recent drinking and binge-drinking of 6 or more doses of alcohol on a single occasion.

CONCLUSION

The higher prevalence of unhealthy lifestyle activities among Roma seem to contribute to these inequalities in cardiovascular diseases morbidity and mortality in comparison with the majority population.

Physical activity and awareness in breast screening attendees in Black Country, UK

This study aimed to determine the physical activity levels and awareness of the influence of physical activity and overweight/obesity on breast cancer risk among NHS breast screening programme (NHSBSP) attendees. One hundred and eighty-eight (white British = 95%; post-menopausal = 80%) attendees completed a demographic and anthropometric data questionnaire, International Physical Activity Questionnaire (IPAQ) and awareness of breast cancer risk factors questionnaire. IPAQ data were reported as continuous measures (MET-min · week(-1)) and as categorical variables (low, moderate and high activities). The highest median physical activity levels were reported in the domestic physical activity domain (756 MET-min · week(-1)). Most participants were categorized as 'moderately active' (45%), while 30% were classified in the 'high activity' and 25% as 'low activity' categories. Almost a third of participants (30%) reported no leisure-time physical activity and 83% reported no vigorous physical activity. There was high awareness of the effects of physical activity (75%) and obesity (80%) on breast cancer risk. No significant differences were found between physical activity categories and awareness that physical activity can reduce breast cancer risk (p > 0.05). However, compared with moderate and high activity categories, participants in the 'low activity' category were significantly more likely to respond that they thought they achieved recommended physical activity levels (p < 0.05). Participants who are unaware of their inadequate physical activity levels may have a less positive intention to increase physical activity levels. Practical strategies aimed to increase knowledge of the recommended physical activity guidelines and facilitate the achievement of these guidelines may be required for NHSBSP attendees.

Preventive care and evaluation of the adolescent with a breast mass

Adolescents have little knowledge of preventive breast care or breast screening, yet exposures in youth influence the risk of future breast disease.Nipple piercing increases the risk of trauma and breast infection. Alcohol consumption, smoking, nutrition, obesity, reproductive factors, previous cancer and chest radiotherapy, family history of breast cancer or genetic mutation increase the risk of breast cancer. Breast cancer is rare in adolescents and currently genetic testing is not recommended in those under 18 years, as medical surveillance is not usually recommended until around 25 years. Screening measures include clinical breast exam every 1 to 3 years, and breast self-awareness in healthy women from 20 years; and at least annual breast self examination, with annual clinical breast examination, mammography and magnetic resonance imaging in high-risk patients from 25 years. Breast ultrasound is used in diagnostic evaluation of breast masses in adolescents as mammography is less sensitive in young women.

Levels of physical activity among a nationally representative sample of people in early old age: results of objective and self-reported assessments

BACKGROUND

Detailed assessment of physical activity (PA) in older adults is required to comprehensively describe habitual PA-levels in this growing population segment. Current evidence of population PA-levels is predominantly based on self-report.

METHODS

We examined PA and sedentary behaviour in a nationally representative sample of British people aged 60-64, using individually-calibrated combined heart-rate and movement sensing and a validated questionnaire (EPAQ2), and the socio-demographic and behavioural factors that may explain between-individual variation in PA.

RESULTS

Between 2006-2010, 2224 participants completed EPAQ2 capturing the past year's activity in four domains (leisure, work, transportation and domestic life) and 1787 participants provided 2-5 days of combined-sensing data. According to objective estimates, median(IQR) physical activity energy expenditure (PAEE) was 33.5 (25.3-42.2) and 35.5 (26.6- 47.3) kJ/kg/day for women and men, respectively. Median (IQR) time spent in moderate-to-vigorous PA (MVPA; >3MET), light-intensity PA (1.5-3 MET) and sedentary (<1.5 MET) was 26.0 (12.3-48.1) min/day, 5.4 (4.2-6.7) h/day and 18.0 (16.6-19.4) h/day, respectively, in women; and 41.0 (18.8-73.0) min/day, 5.2 (4.0-6.5) h/day and 17.9 (16.3-19.4) h/day in men. PAEE and time spent in MVPA were lower and sedentary time was greater in obese individuals, those with poor health, and those with lower educational attainment (women only). Questionnaire-derived PAEE and MVPA tended to have similar patterns of variation across socio-demographic strata. In the whole sample, domestic PA had the greatest relative contribution to total questionnaire-derived PAEE (58%), whereas occupational PA was the main driver among employed participants (54%). Only 2.2% of participants achieved an average of >30 min MVPA per day combined with >60 min strength-training per week.

CONCLUSIONS

The use of both self-report and objective monitoring to assess PA in early old age provides important information on the domains of PA, PAEE and time spent at different intensity levels. Our findings suggest PA levels are generally low and observed patterns of variation indicate specific subgroups who might benefit from targeted interventions to increase PA.

Adolescent physical activity in relation to breast cancer risk

Adolescent physical activity may protect against premenopausal breast cancer. Whether it also prevents postmenopausal breast cancer, and whether associations are independent of adult activity, is unclear. We evaluated this association among 75,669 women in the Nurses' Health Study II. In 1997, participants reported strenuous, moderate, and walking activity (hours/week) at ages 12-13, 14-17, 18-22, and 23-29 years. We estimated metabolic equivalent task hours (MET-h)/week. Participants also reported current physical activity over follow-up. Breast cancer diagnoses (n = 2,697; premenopausal = 1,351; postmenopausal = 965) through 2011 were reported by participants and confirmed with medical records. We additionally stratified analyses by median age at diagnosis. In Cox proportional hazards models adjusted for adolescent characteristics, physical activity from ages 14-22 was modestly inversely associated with premenopausal breast cancer [e.g., hazard ratio (HR) comparing 72+ to <21 MET-h/week 0.81 (95 % confidence interval (CI) 0.69-0.95; p-trend = 0.10) for ages 14-17 and 0.85 (95 % CI 0.71-1.02; p-trend = 0.06 for ages 18-22]. However, adjustment for adult activity and additional breast cancer risk factors attenuated the associations [ages 14-17: 0.85 (95 % CI 0.73-1.00; p-trend = 0.33)]. Associations were stronger among women diagnosed at younger ages [e.g., ages 18-22, HR 0.77 (95 % CI 0.60-0.99; p-trend = 0.05) for women diagnosed before 46.9 years; HR 1.02 (95 % CI 0.79-1.32; p-trend = 0.94) for those diagnosed at/after 46.9 years]. Early life physical activity was not associated with postmenopausal breast cancer. Overall, adolescent physical activity was not associated with breast cancer risk. However, we observed a suggestive inverse association of physical activity at ages 14-22 years with premenopausal breast cancer.

Prospective study of high-risk, BRCA1/2-mutation negative women: the 'negative study'

Background

We previously reported that women from high-risk families who tested negative for a BRCA1 or BRCA2 (BRCA1/2) mutation were four times more likely to develop breast cancer compared to women in the general population. Preventive measures and risk factors for breast cancer development in these high-risk women have not been evaluated to the same extent as BRCA1/2 positive women. Further, there is virtually no scientific evidence about best practices in their management and care. The proposed study will examine a role of genetic and non-genetic factors and develop the systems and parameters for the monitoring and surveillance necessary to help establish guidelines for the care of this high-risk population.

Methods/Design

To achieve our goals, we will assemble and follow a Canadian cohort of 1,000 cancer-free women with a strong family history breast cancer (defined as two or more relatives affected by breast cancer under the age of 50, or three or more relatives diagnosed with breast cancer at any age from one side of the family and with no BRCA1/2 mutation in the family). All eligible participants will be mailed a study package including invitation to participate, consent form, a research questionnaire to collect data regarding family history, reproductive and lifestyle factors, as well as screening and surgery. Usual dietary intake will be assessed by a diet history questionnaire. Biological samples including toenail clippings, urine and blood samples will be collected. These women will be followed every two years by questionnaire to update exposure information, screening practices, surgical and chemoprevention, and disease development.

Discussion

Findings from this study will serve to help establish clinical guidelines for the implementation of prevention, counseling, and treatment practices for women who face an elevated risk of breast cancer due to family history, but who do not carry a BRCA1/2 mutation.

Physical activity and the risk of postmenopausal breast cancer - the Norwegian Women and Cancer Study

Background

The relationship between physical activity (PA) throughout life and the risk of postmenopausal breast cancer overall and by estrogen receptor (ER) and progesterone receptor (PR) status, has been reported, but without consistent results. The present study aimed to investigate PA from young age to adulthood in participants of the Norwegian Women and Cancer (NOWAC) Study, in order to determine whether changes in PA level affect the risk of postmenopausal breast cancer.

Methods

1767 invasive breast cancer cases were identified among 80,202 postmenopausal participants of the NOWAC Study during 8.2 years of median follow-up. PA levels at age 14 years, 30 years and at cohort enrollment were obtained via a self-administered questionnaire. Multivariate Cox proportional hazard regression models were used to estimate relative risks and 95% confidence intervals of the risk of postmenopausal breast cancer overall and by ER/PR status.

Results

Risk of postmenopausal breast cancer overall and by ER/PR status was not associated with physical activity level at enrollment. Women with a low PA level at age 30 had an increased risk of ER+/PR + breast tumors (P for trend = 0.04) compared to women with a moderate physical activity level at age 30. Women with a low physical activity level at all three periods of life had a 20% significantly reduced risk of postmenopausal breast cancer, as well as a reduced risk of ER+/PR + and ER+/PR- breast tumors, compared with women who maintained a moderate physical activity level. However, when analyses were corrected for multiple tests, the result was no longer statistically significant. The findings were consistent over strata of age, body mass index and use of hormone replacement therapy.

Conclusions

The study results from this large Norwegian cohort do not support an association between physical activity at different periods of life and the risk of postmenopausal breast cancer.

Effects of aerobic exercise on cancer-related fatigue in breast cancer patients receiving chemotherapy: a meta-analysis

Increasing scientific evidences suggest that aerobic exercise may improve cancer-related fatigue in breast cancer patients, but many existing studies have yielded inconclusive results. This meta-analysis aimed to derive a more precise estimation of the effects of aerobic exercise on cancer-related fatigue in breast cancer patients receiving chemotherapy. The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched from inception through July 1, 2013 without language restrictions. Crude standardized mean difference (SMD) with 95 % confidence interval (CI) was calculated. Twelve comparative studies were assessed with a total of 1,014 breast cancer patients receiving chemotherapy, including 522 patients in the aerobic exercise group (intervention group) and 492 patients in the usual care group (control group). The meta-analysis results revealed that the Revised Piper Fatigue Scale (RPFS) scores of breast cancer patients in the intervention group were significantly lower than those in the control group (SMD=-0.82, 95% CI=-1.04 ∼ -0.60, P<0.001). However, there was no significant difference in the Functional Assessment of Chronic Illness Treatment-Fatigue scale (FACIT-F) scores between the intervention and control groups (SMD=0.09, 95% CI=-0.07 ∼ 0.25, P=0.224). Subgroup analysis by ethnicity indicated that there were significant differences in RPFS and FACIT-F scores between the intervention and control groups among Asian populations (RPFS: SMD=-1.08, 95% CI=-1.35 ∼ -0.82, P<0.001; FACIT-F: SMD=1.20, 95 % CI=0.70 ∼1.71, P<0.001), but not among Caucasian populations (all P>0.05). The current meta-analysis indicates that aerobic exercise may improve cancer-related fatigue in breast cancer patients receiving chemotherapy, especially among Asian populations.

Association of obesity and circulating adipose stromal cells among breast cancer survivors

A positive association of obesity with breast cancer incidence and mortality is well established. Recent reports indicate that adipose stromal cells (ASCs) play an important role in breast cancer development and progression by producing estrogens and tumor-promoting cytokines. Furthermore, circulating ASCs have been uniquely detected in obese individuals, which is likely due to increased tissue remodeling and cell mobilization. The number of circulating ASCs is even more prominent in obese patients with colon and prostate cancers, both of which are exacerbated by obesity. To determine whether a similar association exists for breast cancer, we collected blood samples from a cohort of breast cancer survivors and enumerated circulating ASCs by flow cytometry on the basis of the previously established ASC-associated immunophenotype (CD34+/CD31-/CD45-). We found significantly higher levels of circulating ASCs (p<0.001) in breast cancer survivors with body mass index (BMI)≥30 kg/m2 than their non-obese counterparts (BMI<30). We also compared circulating ASCs before and after exercise of only the obese subjects enrolled in a 6-month individualized exercise program, but found no statistically significant difference, likely due to limited number of subjects in the study. Our findings suggest that circulating ASCs can serve as a potential biomarker for future studies of the impacts of obesity and physical activity on breast cancer recurrence and survival.

Physical activity, sex steroid, and growth factor concentrations in pre- and post-menopausal women: a cross-sectional study within the EPIC cohort

PURPOSE

Increased physical activity (PA) is associated with a reduced risk of several cancers. PA may reduce cancer risk by changing endogenous hormones levels, but relatively little research has focused on this topic. The purpose of this study was to elucidate the relation between PA and endogenous hormone concentrations.

METHODS

A cross-sectional analysis of 798 pre- and 1,360 post-menopausal women included as controls in case-control studies on endogenous hormones (steroids, progesterone, sex-hormone-binding globulin (SHBG), and growth factors) levels, and cancer risk nested within European Prospective Investigation into Cancer and Nutrition cohort was performed. Multivariate regression analyses were performed to compare geometric mean levels of hormones and SHBG by categories of PA.

RESULTS

In pre-menopausal women, active women had 19 % significantly lower concentrations of androstenedione, 14 % lower testosterone, and 20 % lower free testosterone than inactive women, while no differences were observed for estrogens, progesterone, SHBG, and growth factors. In post-menopausal women, active women had 18 % significantly lower estradiol and 20 % lower free estradiol concentrations than inactive women, while no differences were observed for the other hormones and SHBG. More vigorous forms of physical activity were associated with higher insulin-like growth factor-I concentrations. Adjustment for body mass index did not alter the associations. Overall, the percentage of variance in hormone concentrations explained by PA levels was <2 %.

CONCLUSIONS

Our results support the hypothesis of an influence, although small in magnitude, of PA on sex hormone levels in blood, independent of body size.

A collaborative study of the etiology of breast cancer subtypes in African American women: the AMBER consortium

PURPOSE

Breast cancer is a heterogeneous disease, with at least five intrinsic subtypes defined by molecular characteristics. Tumors that express the estrogen receptor (ER+) have better outcomes than ER- tumors, due in part to the success of hormonal therapies that target ER+ tumors. The incidence of ER- breast cancer, and the subset of ER- cancers that are basal-like, is about twice as high among African American (AA) women as among US women of European descent (EA). This disparity appears to explain, in part, the disproportionately high mortality from breast cancer that occurs in AA women. Epidemiologic research on breast cancer in AA women lags behind research in EA women. Here, we review differences in the etiology of breast cancer subtypes among AA women and describe a new consortium of ongoing studies of breast cancer in AA women.

METHODS

We combined samples and data from four large epidemiologic studies of breast cancer in AA women, two cohort and two case-control, creating the African American Breast Cancer Epidemiology and Risk consortium. Tumor tissue is obtained and stored in tissue microarrays, with assays of molecular markers carried out at a pathology core. Genotyping, carried out centrally, includes a whole exome SNP array and over 180,000 custom SNPs for fine-mapping of genome-wide association studies loci and candidate pathways.

RESULTS

To date, questionnaire data from 5,739 breast cancer cases and 14,273 controls have been harmonized. Genotyping of the first 3,200 cases and 3,700 controls is underway, with a total of 6,000 each expected by the end of the study period.

CONCLUSIONS

The new consortium will likely have sufficient statistical power to assess potential risk factors, both genetic and non-genetic, in relation to specific subtypes of breast cancer in AA women.

Breast cancer mortality vs. exercise and breast size in runners and walkers

Purpose

Identify predictors of breast cancer mortality in women who exercised below (<7.5 metabolic equivalent hours/week, MET-hours/wk), at (7.5 to 12.5 MET-hours/wk), or above (≥12.5 MET-hours/wk) recommended levels.

Methods

Cox proportional hazard analyses of baseline pre-diagnosis MET-hours/wk vs. breast cancer mortality adjusted for follow-up age, race, baseline menopause, and estrogen and oral contraceptive use in 79,124 women (32,872 walkers, 46,252 runners) from the National Walkers' and Runners' Health Studies.

Results

One-hundred eleven women (57 walkers, 54 runners) died from breast cancer during the 11-year follow-up. The decline in mortality in women who exercised ≥7.5 MET-hours/wk was not different for walking and running (P = 0.34), so running and walking energy expenditures were combined. The risk for breast cancer mortality was 41.5% lower for ≥7.5 vs. <7.5 MET-hours/wk (HR: 0.585, 95%CI: 0.382 to 0.924, P = 0.02), which persisted when adjusted for BMI (HR: 0.584, 95%CI: 0.368 to 0.956, P = 0.03). Other than age and menopause, baseline bra cup size was the strongest predictor of breast cancer mortality, i.e., 57.9% risk increase per cup size when adjusted for MET-hours/wk and the other covariates (HR: 1.579, 95%CI: 1.268 to 1.966, P<0.0001), and 70.4% greater when further adjusted for BMI (HR: 1.704, 95%CI: 1.344 to 2.156, P = 10⁻⁵). Breast cancer mortality was 4.0-fold greater (HR: 3.980, 95%CI: 1.894 to 9.412, P = 0.0001) for C-cup, and 4.7-fold greater (HR: 4.668, 95%CI: 1.963 to 11.980, P = 0.0004) for ≥D-cup vs. A-cup when adjusted for BMI and other covariates. Adjustment for cup size and BMI did not eliminate the association between breast cancer mortality and ≥7.5 MET-hour/wk walked or run (HR: 0.615, 95%CI: 0.389 to 1.004, P = 0.05).

Conclusion

Breast cancer mortality decreased in association with both meeting the exercise recommendations and smaller breast volume.