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

Unraveling the link between cardiorespiratory fitness and cancer: a state-of-the-art review

Cardiorespiratory fitness (CRF) not only reflects an individual's capacity to perform physical activities but also encapsulates broader effects on the basic biology of aging. This review aims to summarize the evidence on the influence of CRF on overall and site-specific cancer risks. It delves into the biological mechanisms through which CRF may exert its effects, explores the clinical implications of these findings, identifies gaps in the current evidence base, and suggests directions for future research. The synthesis of findings reveals that higher CRF levels (general threshold of > 7 METs) are consistently associated with a reduced risk of a range of cancers, including head and neck, lung, breast, gastrointestinal, particularly pancreatic and colorectal, bladder, overall cancer incidence and mortality, and potentially stomach and liver, bile duct, and gall bladder cancers. These inverse associations between CRF and cancer risk do not generally differ across age groups, sex, race, or adiposity, suggesting a universal protective effect of CRF. Nonetheless, evidence linking CRF with skin, mouth and pharynx, kidney, and endometrial cancers is limited and inconclusive. Conversely, higher CRF levels may be potentially linked to an increased risk of prostate cancer and hematological malignancies, such as leukemia and myeloma, although the evidence is still not conclusive. CRF appears to play a significant role in reducing the risk of several cancers through various biological mechanisms, including inflammation reduction, immune system enhancement, hormonal regulation, and metabolic improvements. Overall, enhancing CRF through regular physical activity offers a vital, accessible strategy for reducing cancer risk and extending the health span. Future research should aim to fill the existing evidence gaps regarding specific cancers and elucidate the detailed dose-response relationships between CRF levels and cancer risk. Studies are also needed to elucidate the causal relationships and mechanistic pathways linking CRF to cancer outcomes.

The Association between Cardiorespiratory Fitness and the Risk of Breast Cancer in Women

INTRODUCTION

Studies have shown an inverse association between the risk of breast cancer in women and physical activity. However, information on the association between cardiorespiratory fitness (CRF) assessed objectively by a standardized test and the risk of developing breast cancer is limited.

PURPOSE

To examine the CRF-breast cancer risk association in healthy females.

METHODS

This retrospective study was derived from the Exercise Testing and Health Outcomes Study cohort ( n = 750,302). Female participants ( n = 44,463; mean age ± SD; 55.1 ± 8.9 yr) who completed an exercise treadmill test evaluation (Bruce protocol) at the Veterans Affairs Medical Centers nationwide from 1999 to 2020 were studied. The cohort was stratified into four age-specific CRF categories (Least-fit, Low-fit, Moderate-fit, and Fit), based on the peak METs achieved during the exercise treadmill test.

RESULTS

During 438,613 person-years of observation, 994 women developed breast cancer. After controlling for covariates, the risk of breast cancer was inversely related to exercise capacity. For each 1-MET increase in CRF, the risk of cancer was 7% lower (HR, 0.93; 95% CI, 0.90-0.95; P < 0.001). When risk was assessed across CRF categories with the Least-fit group as the referent, the risk was 18% lower for Low-fit women (HR, 0.82; 95% CI, 0.70-0.96; P = 0.013), 31% for Moderate-fit (HR, 0.69; 95% CI, 0.58-0.82; P < 0.001), and 40% for Fit (HR, 0.60; 95% CI, 0.47-0.75; P < 0.001).

CONCLUSIONS

We observed an inverse and graded association between CRF and breast cancer risk in women. Thus, encouraging women to improve CRF may help attenuate the risk of developing breast cancer.

Outcomes of physical exercises on initiation, progression, and treatment of breast cancer

The emergence of drug resistance is a substantial obstacle to the effective management of breast cancer, which is the primary cause of cancer-related deaths in women worldwide. To facilitate the development of targeted therapies that can effectively overcome drug resistance, it is crucial to possess a comprehensive comprehension of the molecular mechanisms that underpin resistance to breast cancer treatment. So far, considerable progress has been made in the field of exercise-oncology research and overcome drug resistance, specifically about breast cancer. Evidence has suggested that participation in physical activity is correlated with a decrease in reappearance and fatality rates of breast cancer patients. It has been reported that participation in physical activity can yield favorable outcomes in the prevention, treatment, and post-treatment of breast cancer. An increasing body of empirical evidence suggests that participation in physical activity can alter diverse biological mechanisms, potentially augmenting breast cancer treatments' efficacy. Comparing increased physical activity versus reduced physical activity in breast cancer patients who received chemotherapy, radiotherapy, and surgery supported the significance of exercise in comprehensive care strategies to enhance overall health and treatment efficacy. Furthermore, previous studies have reported that physical activity can enhance the efficacy of breast cancer treatments. This review provides the current literature regarding the influence of physical activity on the occurrence and progression of breast cancer.

Temporal trends of breast cancer burden in the Western Pacific Region from 1990 to 2044: Implications from the Global Burden of Disease Study 2019

INTRODUCTION

Breast cancer (BC) is a malignant disease that occurs worldwide and poses serious health burden.

OBJECTIVES

To assess the prevalence of BC burden in the Western Pacific region (WPR) from 1990 to 2019, and to predict trends from 2020 to 2044. To analyze the driving factors and put forward the region-oriented improvement.

METHODS

Based on the Global Burden of Disease Study 2019, BC cases, deaths, disability-adjusted life years (DALYs) cases, age-standardized incidence rate (ASIR), age-standardized death rate (ASDR), and age-standardized DALYs rate in WPR from 1990 to 2019 was obtained and analysed. Age-period-cohort (APC) model was used to analyze age, period, and cohort effects in BC, and Bayesian APC (BAPC) was used to predict trends over the next 25 years.

RESULTS

In conclusion, BC incidence and deaths in the WPR have increased rapidly over the past 30 years and are expected to continue to increase between 2020 and 2044. Among behavioral and metabolic factors, high body-mass index was the main risk factor for BC mortality in middle-income countries, whereas alcohol use was the main risk factor in Japan. Age is a key factor in the development of BC, with 40 years being the critical point. Incidence trends coincide with the course of economic development.

CONCLUSIONS

The BC burden remains an essential public health issue in the WPR and will increase substantially in the future. More efforts should be made in middle-income countries to prompt the health behavior and minimize the burden of BC because these nations accounts for the majority of BC burden in the WPR.

Causes and Risk Factors of Breast Cancer, What Do We Know for Sure? An Evidence Synthesis of Systematic Reviews and Meta-Analyses

Breast cancer affected more than 2.3 million women in 2022 and is the most diagnosed cancer among women worldwide. The incidence rates are greater in developed regions and are significantly higher among women with higher education and socioeconomic status. Therefore, it is reasonable to assume that the way women live their lives may impact their risk of being diagnosed with breast cancer. This systematic review aimed to identify what is known about the causes and risk factors of breast cancer, excluding genetic causes. A comprehensive systematic search identified 2387 systematic reviews, 122 were included and six overall themes identified. In our "top list" with the 36 most important findings, a study of breast density had the highest effect size for increasing the risk of breast cancer, and a high sex-hormone-binding globulin level was the most protective factor. Many of the included studies investigating the same topics had conflicting results. The conclusion from this evidence synthesis reveals a lack of consensus of factors associated with the causes and risk of breast cancer. These findings suggest that recommendations about lifestyle and breast cancer should be made with caution.

Healthy Lifestyle and Cancer Risk: Modifiable Risk Factors to Prevent Cancer

Cancer has become a serious problem worldwide, as it represents the main cause of death, and its incidence has increased over the years. A potential strategy to counter the growing spread of various forms of cancer is the adoption of prevention strategies, in particular, the use of healthy lifestyles, such as maintaining a healthy weight, following a healthy diet; being physically active; avoiding smoking, alcohol consumption, and sun exposure; and vitamin D supplementation. These modifiable risk factors are associated with this disease, contributing to its development, progression, and severity. This review evaluates the relationship between potentially modifiable risk factors and overall cancer development, specifically breast, colorectal, and prostate cancer, and highlights updated recommendations on cancer prevention. The results of numerous clinical and epidemiological studies clearly show the influence of lifestyles on the development and prevention of cancer. An incorrect diet, composed mainly of saturated fats and processed products, resulting in increased body weight, combined with physical inactivity, alcohol consumption, and smoking, has induced an increase in the incidence of all three types of cancer under study. Given the importance of adopting correct and healthy lifestyles to prevent cancer, global institutions should develop strategies and environments that encourage individuals to adopt healthy and regular behaviors.

Neighborhood greenness and participation in specific types of recreational physical activities in the Sister Study

BACKGROUND

Urban green spaces have been consistently shown to have important human health benefits across a range of outcomes. These benefits are thought to be achieved, in part, because urban greenness provides opportunities for participation in recreational activity. However, the findings from studies that have assessed links between exposure to greenness and physical activity have been mixed. To date, few studies have examined association between greenness and specific types of recreational physical activities.

OBJECTIVE

We evaluated associations between measures of greenness and specific types of recreational physical activities. Moreover, we explored the extent to which these associations were modified by socioeconomic conditions, and regionally.

METHODS

We analyzed cross-sectional data from 49,649 women in the Sister Study and assigned three residentially-based measures of greenness based on national land cover data at buffer distances of 250 m and 500 m. Data on participation in up to ten specific recreational physical activities, including time spent in each activity were collected. Logistic regression was used to estimate odds ratios (OR) and their 95% confidence intervals (CI) controlling for confounders.

RESULTS

Compared to those in the lowest tertile of greenness, participants in the upper tertile of greenness within a 500 m buffer, were more likely to garden (OR = 1.46, 95% CI = 1.25,1.69), participate in sports (OR = 1.28, 95% CI = 1.19,1.38), run (OR = 1.15, 95% CI = 1.04,1.27), walk (OR = 1.11, 95% CI = 1.06,1.16), and engage in conditioning exercises (OR = 1.10, 95% CI = 1.05,1.16) at least once a week for at least one month over the past year. These associations were modified by household income and US region.

DISCUSSION

Our findings suggest a beneficial effect of greenness on physical activity and provide additional information to inform planning of green environments that contribute to better health and wellbeing.

Breast Cancer and Lifestyle Factors: Umbrella Review

Lifestyle factors play a major role in the risk of breast cancer. This review aimed to examine the size of the effect of select lifestyle factors on risk for breast cancer and assess the quality of existing evidence. The authors performed an umbrella review of systematic reviews. The authors found an increased risk for breast cancer associated with obesity, alcohol intake, and smoking and a decreased risk due to physical activity. The evidence for sleep disruption and duration indicates risk for breast cancer, but it is limited in size, statistical significance, and quality of evidence.

European guidelines for the diagnosis, treatment and follow-up of breast lesions with uncertain malignant potential (B3 lesions) developed jointly by EUSOMA, EUSOBI, ESP (BWG) and ESSO

INTRODUCTION

Breast lesions of uncertain malignant potential (B3) include atypical ductal and lobular hyperplasias, lobular carcinoma in situ, flat epithelial atypia, papillary lesions, radial scars and fibroepithelial lesions as well as other rare miscellaneous lesions. They are challenging to categorise histologically, requiring specialist training and multidisciplinary input. They may coexist with in situ or invasive breast cancer (BC) and increase the risk of subsequent BC development. Management should focus on adequate classification and management whilst avoiding overtreatment. The aim of these guidelines is to provide updated information regarding the diagnosis and management of B3 lesions, according to updated literature review evidence.

METHODS

These guidelines provide practical recommendations which can be applied in clinical practice which include recommendation grade and level of evidence. All sections were written according to an updated literature review and discussed at a consensus meeting. Critical appraisal by the expert writing committee adhered to the 23 items in the international Appraisal of Guidelines, Research and Evaluation (AGREE) tool.

RESULTS

Recommendations for further management after core-needle biopsy (CNB) or vacuum-assisted biopsy (VAB) diagnosis of a B3 lesion reported in this guideline, vary depending on the presence of atypia, size of lesion, sampling size, and patient preferences. After CNB or VAB, the option of vacuum-assisted excision or surgical excision should be evaluated by a multidisciplinary team and shared decision-making with the patient is crucial for personalizing further treatment. De-escalation of surgical intervention for B3 breast lesions is ongoing, and the inclusion of vacuum-assisted excision (VAE) will decrease the need for surgical intervention in further approaches. Communication with patients may be different according to histological diagnosis, presence or absence of atypia, or risk of upgrade due to discordant imaging. Written information resources to help patients understand these issues alongside with verbal communication is recommended. Lifestyle interventions have a significant impact on BC incidence so lifestyle interventions need to be suggested to women at increased BC risk as a result of a diagnosis of a B3 lesion.

CONCLUSIONS

These guidelines provide a state-of-the-art overview of the diagnosis, management and prognosis of B3 lesions in modern multidisciplinary breast practice.

Knowledge, attitudes, and practices related to breast cancer screening among female Jordanian university employees: A cross-sectional study

INTRODUCTION

To improve participation in breast screening programs, the level of knowledge about BC, attitudes, and practices of women in different sections of society must be understood. This study aimed to measure the level of knowledge of BC risk factors, signs and symptoms and determine current mammography practices among female employees at Jordanian universities.

METHODS

A cross-sectional descriptive study was conducted on female employees at Jordanian government universities. Data was collected using a structured questionnaire that included: sociodemographic characteristics, knowledge of BC risk factors, knowledge of BC symptoms and knowledge, attitude and practice of mammography as an early detection method.

RESULTS

A total of 362 participants completed the questionnaire. Overall, 174 scored ≥50% correct answers regarding BC risk factors, while 231 scored ≥50% correct answers regarding BC signs and symptoms. Half of the participants (n = 184, 50.8%) understood mammography to be an early BC detection method. Among those participants, 95 (51.6%) were eligible for screening and 39 (21.2%) had had a previous mammogram. The main reason for not engaging in mammography was the absence of BC signs and symptoms (37.2%). Profession, educational level and family history of BC were associated with increased knowledge of BC risk factors, signs and symptoms (p = 0.01). Lecturers in medical faculties exhibited the highest level of knowledge about mammography compared to participants in other professions (p = 0.02).

CONCLUSION

Only 79 participants had good to excellent knowledge about BC. Participants' profession was the major indicator for awareness of BC and mammography as an early detection method.

IMPLICATIONS FOR PRACTICE

The findings of this study reinforce the importance of providing BC educational programs for university employees in Jordan to increase awareness of BC and mammography.

Dietary pattern and other factors of breast cancer among women: a case control study in Northwest Ethiopia

INTRODUCTION

Breast cancer is presently the most commonly diagnosed cancer in women, and it stands as the leading cause of cancer-related deaths worldwide. Notably, breast cancer rates have seen a significant increase in sub-Saharan African countries, including Ethiopia. Several risk factors contribute to breast cancer, some of which can be modified, while others are inherent. Promoting a healthier diet is strongly encouraged as a preventive measure against breast cancer. However, it's noteworthy that no previous research has investigated the connection between dietary patterns and the risk of breast cancer among Ethiopian women. Therefore, the primary objective of the current study is to examine the relationship between dietary patterns, socioeconomic and behavior factors associated with breast cancer in Ethiopian women.

METHODS

A case-control study was conducted at an institution in Bahir Dar, Northwest Ethiopia, involving 260 women, comprising 86 cases and 174 controls. We administered a standardized and validated questionnaire to assess a range of sociodemographic, reproductive, clinical, lifestyle, and dietary characteristics through face-to-face interviews. To analyze the differences between the cases and controls, we employed the Chi-square test. Furthermore, we assessed the relationships between these variables using binary multivariate logistic regression. To measure the association between variables, we utilized odds ratios with 95% confidence intervals.

RESULTS

The results of the multivariate analysis indicated that participants in the younger age group had significantly lower odds of developing breast cancer (AOR = 0.05; 95% CI: 0.00-0.91) compared to those in the older age group. Additionally, women who breastfed their children for shorter durations were 3.66 times more likely to develop breast cancer (AOR = 3.66; 95% CI: 2.78-6.89) than those who breastfed for longer periods. Furthermore, women with sedentary lifestyles faced a significantly higher risk of breast cancer, with odds 10.53 times greater (AOR = 10.53; 95% CI: 5.21-21.36) than their counterparts who engaged in moderate or highly active lifestyles. Lastly, participants who had previously undergone chest therapy were 6.43 times more likely to develop breast cancer (AOR = 6.43; 95% CI: 3.20-13.90) compared to those who had not.

CONCLUSIONS

Breast cancer prevention interventions, including breastfeeding counseling and increased physical activity should be recognized as a central strategy for lowering breast cancer risk. Furthermore, healthcare providers should aim to minimize exposure to chest radiation therapy.

Association between Gut Microbiota and Breast Cancer: Diet as a Potential Modulating Factor

Breast cancer (BCa) has many well-known risk factors, including age, genetics, lifestyle, and diet; however, the influence of the gut microbiome on BCa remains an emerging area of investigation. This study explores the connection between the gut microbiome, dietary habits, and BCa risk. We enrolled newly diagnosed BCa patients and age-matched cancer-free controls in a case-control study. Comprehensive patient data was collected, including dietary habits assessed through the National Cancer Institute Diet History Questionnaire (DHQ). 16S rRNA amplicon sequencing was used to analyze gut microbiome composition and assess alpha and beta diversity. Microbiome analysis revealed differences in the gut microbiome composition between cases and controls, with reduced microbial diversity in BCa patients. The abundance of three specific microbial genera-Acidaminococus, Tyzzerella, and Hungatella-was enriched in the fecal samples taken from BCa patients. These genera were associated with distinct dietary patterns, revealing significant associations between the presence of these genera in the microbiome and specific HEI2015 components, such as vegetables and dairy for Hungatella, and whole fruits for Acidaminococus. Demographic characteristics were well-balanced between groups, with a significantly higher body mass index and lower physical activity observed in cases, underscoring the role of weight management in BCa risk. Associations between significant microbial genera identified from BCa cases and dietary intakes were identified, which highlights the potential of the gut microbiome as a source of biomarkers for BCa risk assessment. This study calls attention to the complex interplay between the gut microbiome, lifestyle factors including diet, and BCa risk.

Dose response relationship between breast cancer and somatotypes during childhood: a systematic review and meta-analysis

OBJECTIVES

This study aims to evaluate the relationship between breast cancer and somatotypes during early life by meta-analysis and give the corresponding advice.

METHODS

Observational studies till April 5, 2021, which explore women with/without breast cancer who used the Stunkard Figure Rating Scale/Sørensen Somatotypes to evaluate their somatotype before 18 years of age and distant breast cancer risk were included. Using random/fixed-effect models, the pooled relative risks (RRs) and 95% confidence intervals (CIs) were estimated. Then a nonlinear dose-response meta-analysis was conducted using restricted cubic spline analysis.

RESULTS

Six articles involving 15,211 breast cancer patients from 341,905 individuals were included for performing a meta-analysis of early somatotype and breast cancer risk. The pooled results showed that the protection became stronger with the increase of somatotype until it reached 6. The restricted cubic spline model indicated a linear relationship between somatotypes and breast cancer (P-nonlinearity = 0.533). Subgroup analysis of menopausal status showed that increasing somatotype during childhood was increasingly protective against postmenopausal breast cancer from somatotype 3 to somatotype 6, with a 0.887-fold (RR = 0.887, 95% CI: 0.842, 0.934) to 0.759-fold (RR = 0.759, 95% CI: 0.631, 0.913) decreased risk of breast cancer (P-nonlinearity = 0.880), but this association was not found in the population with premenopausal breast cancer (P-nonlinearity = 0.757). When stratified by age, among people younger than 10 years of age, an increase in somatotype was associated with a statistically significant reduction in breast cancer risk. From somatotype 3 to somatotype 6, the risk of breast cancer was reduced by 9.7-27.7% (P-nonlinearity = 0.175).

CONCLUSIONS

With early-life adiposity, our data support an inverse association with breast cancer risk, especially age less than 10 years and in postmenopausal women. Since girls with overweight likely remain overweight or even develop obesity in adulthood. While adults with overweight and obese are at increased risk of breast cancer and other types of cancer and various chronic diseases. Hence, we recommend that children should maintain a normal or slightly fat somatotype throughout all periods of life.

Latin American and the Caribbean Code Against Cancer 1st edition: Weight, physical activity, diet, breastfeeding, and cancer

In Latin America and the Caribbean a considerable proportion of the population have excess body weight, do not meet the recommendations of physical activity and healthy diet, and have suboptimal rates of breastfeeding. Excess body weight is associated with at least 15 cancer sites, physical activity protects against three cancers, with some evidence suggesting a protective effect for eight more cancer sites, and sedentary behavior probably increases the risk of five cancer sites. Fiber and wholegrains protect against colorectal cancer, high intake of fruits and vegetables could reduce the risk of aerodigestive cancers; processed and red meat increase the risk of colorectal cancer; and very hot beverages are associated with esophageal cancer. Moreover, sugar-sweetened beverages and ultra-processed foods are a convincing cause for excess body weight, increasing cancer risk through this pathway, with some emerging evidence suggesting also direct pathways. Breastfeeding protects against breast cancer, and could protect against ovarian cancer. Taking this evidence into account, the Latin America and the Caribbean Code Against Cancer recommends the general public to maintain a healthy body weight, be physically active and limit sedentary behavior, eat a healthy diet (eat plenty of vegetables, fruits, wholegrains and legumes; avoid sugar-sweetened beverages and processed meat; and limit ultra-processed foods, red meat and very hot beverages), and breastfeed. Moreover, the Latin America and the Caribbean Code Against Cancer also includes a set of public policy recommendations for cancer prevention to inform policy makers and civil society about the need of policies to shape healthy environments and create opportunities to facilitate the adoption of the recommendations directed to the public.

Bioinformatic Identification of Hub Genes Related to Menopause-Obesity Paradox in Breast Cancer

Background

Breast cancer (BC) is one of the most common cancers in women, significantly contributing to cancer-related death in the modern world. Obesity, as a worldwide epidemic besides the menopausal status, has a paradoxical association with BC.

Objectives

To determine the molecular mechanisms underlying the paradoxical effects of obesity on BC, a comprehensive systems biology analysis was performed.

Methods

Data retrieval, data preprocessing, and differential expression analysis were conducted. Weighted correlation network analysis (WGCNA) identified the gene modules associated with clinical traits. Network analysis and hub gene identification techniques revealed key regulatory genes, and functional enrichment analysis uncovered biological pathways related to hub genes. A logistic regression model was developed to predict menopausal status based on hub genes. Additionally, gene expression analysis of two important genes was performed by qPCR.

Results

The study identified the hub genes and molecular pathways (the PI3K-Akt signaling pathway, proteoglycans in cancer, and lipid metabolic and atherosclerosis pathways) associated with the obesity paradox in BC based on menopausal statutes.

Conclusions

These results may improve our understanding of the underlying mechanisms of the effects of body mass on BC and assist in identifying biomarkers and potential therapeutic targets for treating obese postmenopausal women with BC.

Lifestyle Factors and Energy Intakes with Risks of Breast Cancer among Pre- and Post- Menopausal Women in Taiwan

Although the incidence of invasive breast cancer (BC) among women in Asian is generally lower than that in Western countries, the incidence of BC has been on the rise in the past three decades in Asian countries. This hospital-based case-control study aimed to explore the relationship between dietary and metabolic factors and BC risk in pre- and post-menopausal women. We enrolled 285 patients with newly diagnosed BC at the National Taiwan University Hospital and 297 controls from the local community and hospital staff. Before receiving anticancer therapy, all patients with BC and control participants completed a 57-question semi-quantitative Food Frequency Questionnaire. For pre-menopausal women, plant-based factor scores rich in seeds and nuts, soy, fruits, and seaweeds correlated significantly with reduced BC risks, whereas menarche occurring at <12 years of age, reduced physical activity, and high-density lipoprotein <40 mg/dL were associated with increased BC risks. For post-menopausal women, plant-based dietary factor scores were also associated with reduced risks, whereas increased body mass index and energy intake levels correlated with increased BC risks. Diets rich in plant-based dietary patterns are protective against BC risk, regardless of menopausal status. Habitual physical activity is protective against BC risk among pre-menopausal Taiwanese women. Maintaining optimal weight and caloric intake is beneficial for reducing post-menopausal BC risk.

Geographical Variation in Social Determinants of Female Breast Cancer Mortality Across US Counties

Importance

Breast cancer mortality is complex and traditional approaches that seek to identify determinants of mortality assume that their effects on mortality are stationary across geographic space and scales.

Objective

To identify geographic variation in the associations of population demographics, environmental, lifestyle, and health care access with breast cancer mortality at the US county-level.

Design, Setting, and Participants

This geospatial cross-sectional study used data from the Surveillance, Epidemiology, and End Results (SEER) database on adult female patients with breast cancer. Statistical and spatial analysis was completed using adjusted mortality rates from 2015 to 2019 for 2176 counties in the US. Data were analyzed July 2022.

Exposures

County-level population demographics, environmental, lifestyle, and health care access variables were obtained from open data sources.

Main Outcomes and Measures

Model coefficients describing the association between 18 variables and age-adjusted breast cancer mortality rate. Compared with a multivariable linear regression (OLS), multiscale geographically weighted regression (MGWR) relaxed the assumption of spatial stationarity and allowed for the magnitude, direction, and significance of coefficients to change across geographic space.

Results

Both OLS and MGWR models agreed that county-level age-adjusted breast cancer mortality rates were significantly positively associated with obesity (OLS: β, 1.21; 95% CI, 0.88 to 1.54; mean [SD] MGWR: β, 0.72 [0.02]) and negatively associated with proportion of adults screened via mammograms (OLS: β, -1.27; 95% CI, -1.70 to -0.84; mean [SD] MGWR: β, -1.07 [0.16]). Furthermore, the MGWR model revealed that these 2 determinants were associated with a stationary effect on mortality across the US. However, the MGWR model provided important insights on other county-level factors differentially associated with breast cancer mortality across the US. Both models agreed that smoking (OLS: β, -0.65; 95% CI, -0.98 to -0.32; mean [SD] MGWR: β, -0.75 [0.92]), food environment index (OLS: β, -1.35; 95% CI, -1.72 to -0.98; mean [SD] MGWR: β, -1.69 [0.70]), exercise opportunities (OLS: β, -0.56; 95% CI, -0.91 to -0.21; mean [SD] MGWR: β, -0.59 [0.81]), racial segregation (OLS: β, -0.60; 95% CI, -0.89 to -0.31; mean [SD] MGWR: β, -0.47 [0.41]), mental health care physician ratio (OLS: β, -0.93; 95% CI, -1.44 to -0.42; mean [SD] MGWR: β, -0.48 [0.92]), and primary care physician ratio (OLS: β, -1.46; 95% CI, -2.13 to -0.79; mean [SD] MGWR: β, -1.06 [0.57]) were negatively associated with breast cancer mortality, and that light pollution was positively associated (OLS: β, 0.48; 95% CI, 0.24 to 0.72; mean [SD] MGWR: β, 0.27 [0.04]). But in the MGWR model, the magnitude of effect sizes and significance varied across geographical regions. Inversely, the OLS model found that disability was not a significant variable for breast cancer mortality, yet the MGWR model found that it was significantly positively associated in some geographical locations.

Conclusions and Relevance

This cross-sectional study found that not all social determinants associated with breast cancer mortality are spatially stationary and provides spatially explicit insights for public health practitioners to guide geographically targeted interventions.

Associations between changes of smartphone pedometer-assessed step counts and levels of obesity-related breast cancer biomarkers in non-cancer women: A population-based observational study

While a higher level of physical activity (PA) is inversely associated with a higher breast cancer (BC) risk, the health benefits of daily steps on obesity-related BC biomarkers remain unclear. We aimed to understand the associations of changes in step counts with levels of five obesity-related BC biomarkers during a two-year follow-up. In total, 144 non-cancer women (47.96 ± 5.72) were observed on both 2019 and 2021. A structured questionnaire, daily steps and fasting blood samples were collected before (t0, 2019) and after (t1, 2021). Levels of biomarkers (IGF-binding proteins 3, adiponectin, soluble leptin receptor, C-reactive protein, and resistin) were assayed by ELISA. Participants were divided into persistent low steps, decreasing steps, increasing steps, and persistent high steps. Associations of categories on proposed biomarkers were estimated using linear regression models, with persistent low steps as reference. Associations between time-varying step counts with biomarkers were quantified using mixed linear models. Compared with persistent low steps, increasing steps is associated with a reduction in C-reactive protein level (β=-0.74, 95%CI=-1.23--0.26, P-value = 2.98 × 10-3). An inverse association between time-varying step counts with C-reactive protein level was identified, consistent across different obesity types and baseline step level categories. No association with daily step counts was observed for other proteins.

Accelerometer-measured physical activity and postmenopausal breast cancer incidence in the Women's Health Accelerometry Collaboration

BACKGROUND

Few studies have examined accelerometer-measured physical activity and incident breast cancer (BC). Thus, this study examined associations between accelerometer-measured vector magnitude counts per 15 seconds (VM/15s) and average daily minutes of light physical activity (LPA), moderate-to-vigorous PA (MVPA), and total PA (TPA) and BC risk among women in the Women's Health Accelerometry Collaboration (WHAC).

METHODS

The WHAC comprised 21,089 postmenopausal women (15,375 from the Women's Health Study [WHS]; 5714 from the Women's Health Initiative Objective Physical Activity and Cardiovascular Health Study [OPACH]). Women wore an ActiGraph GT3X+ on the hip for ≥4 days and were followed for 7.4 average years to identify physician-adjudicated in situ (n = 94) or invasive (n = 546) BCs. Multivariable stratified Cox regression estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for tertiles of physical activity measures in association with incident BC overall and by cohort. Effect measure modification was examined by age, race/ethnicity, and body mass index (BMI).

RESULTS

In covariate-adjusted models, the highest (vs. lowest) tertiles of VM/15s, TPA, LPA, and MVPA were associated with BC HRs of 0.80 (95% CI, 0.64-0.99), 0.84 (95% CI, 0.69-1.02), 0.89 (95% CI, 0.73-1.08), and 0.81 (95% CI, 0.64-1.01), respectively. Further adjustment for BMI or physical function attenuated these associations. Associations were more pronounced among OPACH than WHS women for VM/15s, MVPA, and TPA; younger than older women for MVPA; and women with BMI ≥30 than <30 kg/m2 for LPA.

CONCLUSION

Greater levels of accelerometer-assessed PA were associated with lower BC risk. Associations varied by age and obesity and were not independent of BMI or physical function.

Associations of Physical Activity With Breast Cancer Risk: Findings From the UK Biobank Prospective Cohort Study

PURPOSE

Although physical activity (PA) has been consistently associated with breast cancer, existing evidence is limited to self-reported physical activity, which is prone to dilution bias. Therefore, this aims to examine the associations of device-measured PA domains with breast cancer risk and whether it differs by menopausal status.

METHODS

Prospective cohort study. Data from 48,286 women from the UK Biobank cohort were analyzed. A wrist triaxial accelerometer was used to collect physical activity data for light, moderate, vigorous, moderate to vigorous, and total PA. Cox proportional models were performed to examine the association between PA domains, menopausal status, and breast cancer risk.

RESULTS

Eight hundred thirty-six breast cancer cases were diagnosed during a median of 5.4 years (interquartile range: 4.7-5.9). For total PA, those in the most active quartile had a 26% lower risk of breast cancer (Hazard ratio [HR]: 0.74; 95% confidence interval [CI], 0.61-0.91) compared with those least active. Similar results were observed for light PA (HR: 0.79; 95% CI, 0.64-0.96), and moderate to vigorous PA (HR: 0.78; 95% CI, 0.64-0.96). However, moderate PA (HR: 0.73; 95% CI, 0.44-1.19) and vigorous PA (HR: 0.77; 95% CI, 0.56-1.05) was nonsignificant. No evidence of interaction between PA domains and menopause status was found (P > .10).

CONCLUSION

High levels of PA are associated with a lower risk of breast cancer with similar magnitude of associations observed across different intensity domains.

What Is Known about Breast Cancer in Young Women?

Breast cancer (BC) is the second leading cause of cancer-related death in women under the age of 40 years worldwide. In addition, the incidence of breast cancer in young women (BCYW) has been rising. Young women are not the focus of screening programs and BC in younger women tends to be diagnosed in more advanced stages. Such patients have worse clinical outcomes and treatment complications compared to older patients. BCYW has been associated with distinct tumour biology that confers a worse prognosis, including poor tumour differentiation, increased Ki-67 expression, and more hormone-receptor negative tumours compared to women >50 years of age. Pathogenic variants in cancer predisposition genes such as BRCA1/2 are more common in early-onset BC compared to late-onset BC. Despite all these differences, BCYW remains poorly understood with a gap in research regarding the risk factors, diagnosis, prognosis, and treatment. Age-specific clinical characteristics or outcomes data for young women are lacking, and most of the standard treatments used in this subpopulation currently are derived from older patients. More age-specific clinical data and treatment options are required. In this review, we discuss the epidemiology, clinicopathologic characteristics, outcomes, treatments, and special considerations of breast cancer in young women. We also underline future directions and highlight areas that require more attention in future studies.

Trajectory of physical activity frequency and cancer risk: Findings from a population-based cohort study

BACKGROUND

Physical activity (PA) changes throughout an individual's life, but the association between such changes and cancer risk seems to be overlooked in the literature. Thus, this study aimed to examine the association between the trajectories of PA frequency and cancer incidence among middle-aged Korean adults.

METHODS

A total of 1,476,335 eligible participants (992,151 men and 484,184 women) aged ≥40 years from the National Health Insurance Service cohort (2002-2018) were included. Assessment of PA frequency was a self-reported measure, based on the question: "How many times per week do you perform exercise that makes you sweat?". PA frequency trajectories (i.e., trajectory classes of change in PA frequency) from 2002 to 2008 were identified using group-based trajectory modeling. Cox proportional hazards regression was used to assess the associations between the PA trajectories and cancer incidence.

RESULTS

Five PA frequency trajectories over 7 years were identified: persistently low (men:73.5%; women:74.7%), persistently moderate (men:16.2%; women:14.6%), high-to-low (men:3.9%; women:3.7%), low-to-high (men:3.5%; women:3.8%), and persistently high (men:2.9%; women:3.3%). Compared with persistently low frequency, maintaining a high PA frequency was associated with a lower risk of all cancers (Hazard ratio (HR) = 0.92, 95%CI = 0.87-0.98) and breast cancer (HR = 0.82, 95%CI = 0.70-0.96) among women. There was a lower risk for thyroid cancer among men in the high-to-low (HR = 0.83, 95%CI = 0.71-0.98), low-to-high (HR = 0.80, 95%CI = 0.67-0.96), and high PA trajectories (HR = 0.82, 95%CI = 0.68-0.99). There was a significant association between moderate trajectory and lung cancer in men (HR = 0.88, 95%CI = 0.80-0.95), in both smoking and non-smoking men.

CONCLUSION

Long-term persistent high frequency of PA as part of the daily routine should be widely promoted and encouraged to reduce the risk for all cancer development in women.

The role of exercise in obesity-related cancers: Current evidence and biological mechanisms

Cancer ranks among the five leading causes of death in almost all countries and has important repercussions for individual and public health, the healthcare system, and society in general. Obesity increases the incidence of many types of cancer, but growing evidence suggests that physical activity may decrease risk for developing a variety of obesity-related cancer types, and, in some cases, may improve cancer prognosis and mortality rates. This review summarizes recent evidence on the effect of physical activity on obesity-related cancer prevention and survival. For some cancers, including breast, colorectal, and endometrial cancer, there is strong evidence for a preventative effect of exercise, but for many others, including gallbladder and kidney cancer, and multiple myeloma, evidence is inconsistent or largely lacking. Though many potential mechanisms have been proposed to explain the onco-protective effect of exercise, including improved insulin sensitivity, alterations in sex hormone availability, improved immune function and inflammation, myokine secretion, and modulation of intracellular signaling at the level of AMP kinase, the exact mechanism(s) of action within each cancer subtype remains poorly defined. Overall, a deeper understanding of how exercise can help against cancer and of the exercise parameters that can be altered to optimize exercise prescription is necessary and should be the subject of future investigation.

Comparison of Quality of Life in Breast Cancer Survivors with and without Persistent Depressive Symptoms: A 12-Month Follow-Up Study

Although breast cancer treatments reduce mortality, their adverse effects can increase depression which impacts one's quality of life (QoL). Physical activity (PA) seems to improve the QoL of breast cancer survivors (BCS). However, an unanswered question is the influence of PA on the QoL in BCS with depressive symptoms. Thus, we analyzed the influence of PA on the QoL in BCS with persistent depressive symptoms during 12 months of follow-up. The sample included 70 female BCS. Depression and QoL domains (i.e., functional capacity, physical limitations, body pain, general health status, vitality, social and emotional aspects, and mental health) were assessed at baseline and follow-up periods by the Hospital Anxiety and Depression Scale and SF-36, respectively. Habitual PA was assessed by Baecke's questionnaire. Our results indicate a prevalence of 17.1% of depressive symptoms. Non-depressives BCS improved their physical limitations and general health status domains over time, but there were no observed differences in depressive BCS. BCS with persistent depressive symptoms (baseline and follow-up) showed worse QoL scores than non-depressives in all domains, regardless of confounding factors. When adjusted for PA, the difference between BCS depressives and non-depressives lost its significance in the functional capacity domain. In conclusion, habitual PA practice positively influenced the functional capacity domain of the QoL in BCS.

Dietary Patterns, Dietary Interventions, and Mammographic Breast Density: A Systematic Literature Review

BACKGROUND

Breast cancer (BC) is the most common and deadliest malignancy among women. High mammographic breast density (MBD) is an established modifiable risk marker for BC, and it is of interest, for prevention purposes, to consider lifestyle factors that may modulate both MBD and BC risk. Here, we conducted a systematic review of the most up-to-date evidence on the association between diet as a whole and MBD.

METHODS

We considered as eligible for inclusion in our review (PROSPERO registration code CRD42022335289) the studies published until 31 December 2021, that reported on the association between a priori or a posteriori dietary patterns (in observational studies) or dietary interventions (in randomized controlled trials) and MBD.

RESULTS

In total, twelve studies were included. MBD tended to be inversely associated with adherence to dietary patterns characterized by high consumption of plant-based foods and low in meat, animal fats, and alcohol, defined both a priori (e.g., Mediterranean diet and WCRF/AICR guidelines) or a posteriori (e.g., "fruit-vegetable-cereal" and "salad-sauce-pasta/grains" patterns). Findings from intervention studies were in fair agreement with those from observational studies.

CONCLUSIONS

While further studies are needed, we found suggestive evidence that the adoption of a healthy diet is associated with lower MBD.

The association of health behaviors prior to cancer diagnosis and functional aging trajectories after diagnosis: Longitudinal cohort study of middle-aged and older US cancer survivors

We aimed to determine the influence of modifiable health behaviors prior to a cancer diagnosis on functional aging trajectories after diagnosis among middle-aged and older cancer survivors in the United States. Data were from biennial interviews with 2,717 survivors of a first incident cancer diagnosis after age 50 in the population-based US Health and Retirement Study from 1998 to 2016. Smoking status, alcohol use, and vigorous physical activity frequency were assessed at the interview prior to cancer diagnosis. Confounder-adjusted multinomial logistic regression was used to determine the associations between each pre-diagnosis health behavior and post-diagnosis trajectories of memory function and limitations to activities of daily living (ADLs), which were identified using group-based trajectory modeling. Overall, 20.7 % of cancer survivors were current smokers, 30.6 % drank alcohol, and 27.1 % engaged in vigorous physical activity >=once a week prior to their diagnosis. In the years following diagnosis, those who had engaged in vigorous physical activity > once a week were less likely to have a medium-high (OR: 0.5; 95 % CI: 0.2-0.9) or medium-low memory loss trajectories (OR: 0.6; 95 % CI: 0.3-1.0) versus very low memory loss trajectory, and were less likely to have a high, increasing ADL limitation trajectory (OR: 0.3; 95 % CI: 0.2, 0.6) versus no ADL limitation trajectory. Vigorous physical activity, but not smoking or alcohol use, was associated with better post-diagnosis functional aging trajectories after a first incident cancer diagnosis in mid-to-later life in this population-based study. Identification of modifiable risk factors can inform targeted interventions to promote healthy aging among cancer survivors.

Promote Community Engagement in Participatory Research for Improving Breast Cancer Prevention: The P.I.N.K. Study Framework

Breast cancer (BC) has overtaken lung cancer as the most common cancer in the world and the projected incidence rates show a further increase. Early detection through population screening remains the cornerstone of BC control, but a progressive change from early diagnosis only-based to a personalized preventive and risk-reducing approach is widely debated. Risk-stratification models, which also include personal lifestyle risk factors, are under evaluation, although the documentation burden to gather population-based data is relevant and traditional data collection methods show some limitations. This paper provides the preliminary results from the analysis of clinical data provided by radiologists and lifestyle data collected using self-administered questionnaires from 5601 post-menopausal women. The weight of the combinations of women's personal features and lifestyle habits on the BC risk were estimated by combining a model-driven and a data-driven approach to analysis. The weight of each factor on cancer occurrence was assessed using a logistic model. Additionally, communities of women sharing common features were identified and combined in risk profiles using social network analysis techniques. Our results suggest that preventive programs focused on increasing physical activity should be widely promoted, in particular among the oldest women. Additionally, current findings suggest that pregnancy, breast-feeding, salt limitation, and oral contraception use could have different effects on cancer risk, based on the overall woman's risk profile. To overcome the limitations of our data, this work also introduces a mobile health tool, the Dress-PINK, designed to collect real patients' data in an innovative way for improving women's response rate, data accuracy, and completeness as well as the timeliness of data availability. Finally, the tool provides tailored prevention messages to promote critical consciousness, critical thinking, and increased health literacy among the general population.

Physical activity from menarche-to-first pregnancy and risk of breast cancer: the California teachers study

PURPOSE

A longer menarche-to-first pregnancy window of susceptibility (WOS) is associated with increased breast cancer risk. Whether physical activity, an established preventive risk factor, during the menarche-to-first pregnancy WOS offsets breast cancer risk overall or for specific molecular subtypes is unclear.

METHODS

We examined the prospective association between physical activity during the menarche-to-first pregnancy WOS and breast cancer risk in the California Teachers Study (N = 78,940). Recreational physical activity at multiple timepoints were recalled at cohort entry, and converted to metabolic equivalent of task hours per week (MET-hrs/wk). We used multivariable Cox proportional hazards models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

We observed 5,157 invasive breast cancer cases over 21.6 years of follow-up. Longer menarche-to-first pregnancy WOS (≥ 20 vs. < 15 years) was associated with higher breast cancer risk (HR = 1.23, 95% CI = 1.13-1.34). Women with higher physical activity level during menarche-to-first pregnancy had lower risk of invasive breast cancer (≥ 40 vs. < 9 MET-hrs/wk: HR = 0.89, 95% CI = 0.83-0.97) and triple-negative subtype (≥ 40 vs. < 9 MET-hrs/wk: HR = 0.53, 95% CI = 0.32-0.87). No association was observed for luminal A-like and luminal B-like subtypes. Higher physical activity level was associated with lower breast cancer risk among women with moderate (15-19 years) menarche-to-first pregnancy intervals (≥ 40 vs. < 9 MET-hrs/wk: HR = 0.80, 95% CI = 0.69-0.92), but not with short (< 15 years) or long (≥ 20 years) intervals.

CONCLUSION

Physical activity during a WOS was associated with lower breast cancer risk in our cohort. Understanding timing of physical activity throughout the life course in relationship with breast cancer risk maybe important for cancer prevention strategies.

Association of risk factors and breast cancer among women treated at Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia: a case-control study

OBJECTIVES

Many factors known to increase the risk of breast cancer, such as age, family history, early menarche and late menopause are not modifiable. Modifiable factors include obesity, use of menopausal hormones and breast feeding. This study aimed to assess risk factors associated with breast cancer among women at Tikur Anbessa Specialized Hospital.

DESIGN

Facility based case-control study.

METHODS

Case-control study was conducted from May 2018 to June 2019. A total of 230 cases and 230 controls participated in the study. Data were analysed using SPSS software. Multivariable logistic model based analysis was conducted to control the effect of potential confounding factors. ORs and 95% CI for the likelihood of developing breast cancer were calculated.

RESULTS

The odds of breast cancer was higher among women between 40 and 49 years (adjusted OR (AOR): 3.29, 95% CI 1.39 to 7.77), and being unemployed (AOR: 4.28, 95% CI 2.00 to 9.16). Regarding life style risk factors, women consuming solid oil and using wood or animal dung as source of fuel had significantly higher odds of breast cancer. In addition, the odds of breast cancer was significantly higher among postmenopausal women, women who had previous benign surgery and women with early menarche (<12 years). On the other hand, the odd of breast cancer was significantly lower among women who had moderate physical activities.

CONCLUSION

This study showed that occupational status, consumption of solid oil, and using wood or animal dung as source of fuel, early menarche, menopausal status and previous benign breast surgery were associated with breast cancer. On the other hand, physical activity was protective factor. Therefore, there is a need to design appropriate intervention to educate women about life style change or behaviour modification to decrease their breast cancer risk.

Krebsrisiko bei Prädiabetes und Typ-2-Diabetes mellitus

Krebs ist nun die führende Todesursache bei Typ-2-Diabetes mellitus (T2D). Prädiabetes und T2D erhöhen das Risiko für bestimmte Tumoren. Zu den Prädiabetes- bzw. T2D-assoziierten Malignomen zählen gastrointestinale, gynäkologische, urologische und endokrine Karzinome aber auch Leukämien. Prädiabetes und T2D bedingen eine 1,2- bis 2,7-fach erhöhte Krebssterblichkeit. Zugrundeliegende Mechanismen der Assoziation zwischen T2D und Krebs beinhalten die chronische Hyperglykämie, einen chronischen systemischen Entzündungszustand, oxidativen Stress, Dyslipidämie, die Insulinresistenz sowie chronisch erhöhte Spiegel von insulin-like growth factor 1 (IGF-1) und von Insulin. Eine dauerhafte Gewichtsreduktion kann das Krebsrisiko adipöser T2D-Patienten signifikant senken. Ein gesunder Lebensstil und die regelmäßige Teilnahme an Vorsorgeuntersuchungen sind wichtig und können die Krebsmortalität von Diabetespatienten erheblich verringern.

Association between Physical Activity and Telomere Length in Women with Breast Cancer: A Systematic Review

The association between physical activity and telomere length (TL) has been continuously reported. However, the interplay of physical activity and TL among women with breast cancer has not been elucidated. Thus, the purpose of this systematic review was to synthesize the evidence for the association of physical activity with TL in women with breast cancer. Systematic searches were conducted to identify quantified studies using MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, and Clinical Trials.gov. Five studies were included in this systematic review. Three of the five studies reported that physical activity has a significant relationship in delaying TL shortening, but others observed no association between physical activity and TL in breast cancer survivors. Although the heterogeneous studies acted as limitations in drawing clear conclusions, physical activity strategies show encouraging impacts in delaying TL shortening. To understand the effects of physical activity on TL shortening in breast cancer survivors, further studies are needed considering the tissue site, treatments for breast cancer, DNA extraction methods, and tools for measuring physical activity.

Lifestyle and Socioeconomic Transition and Health Consequences of Breast Cancer in the East Asia Region, From 1990 to 2019

Background

Due to its higher prevalence and heterogeneity, female breast cancer (BC) is the widest disease throughout the world. We sought to assess the epidemiological and sociodemographic transitions of BC and to identify the potential risk factors attributed to burden of BC in East Asia.

Methods

At the regional level of East Asia and at a national level of East Asian countries, we investigated the burden of the incidence of female BC, mortality, and disability-adjusted life years (DALYs) in 2019 and assessed the epidemiological, socioeconomic, and health-linked disparities in incidence of BC and mortality over a 30-year period. The changes in BC’s mortality and DALYs between 1990 and 2019, attributable to varying risk factors, were evaluated in different age groups.

Results

In 2019, the incidence of and mortality from and DALYs of BC were estimated to be 382,321 (95% UI: 303,308–477,173) incidence cases [age-standardized rate (ASR) of 35.69 per 100,000; 28.32–44.54], 98,162 (79,216–120,112) deaths (ASR of 9.12; 7.36–11.13), and 3,024,987 (2,477, 984–3,659,370) DALYs with an ASR of 282.15 (230.81–341.19) in 2019. It was also observed that out of four most representative locations of East Asia, two (China and Japan) showed more than 60% increase in age-standardized incidence rate between 1990 and 2019. While only Japan females showed a significant rise of 15.3% (95% UI: 2.3–28) in ASR of death and 12.6% (95% UI: 0.5–26.9) in ASR of DALYs between 1990 and 2019. Inclusively, 88 and 81% variations were explained in the incidence of BC and death due to change in sociodemographic index (SDI) in 2019, in East Asia. The highest positive percent changes in death and DALYs between 1990 and 2019 were attributable to high body mass index (BMI), high fasting plasma glucose (FPG), and alcohol consumption in East Asia.

Conclusion

The burden of death and disability from female BC is the result of multiple risk factors, mainly due to behavioral and metabolic risk factors. The increase of the incidence is related to the westernized lifestyle and diet habits and the improvement of screening and diagnosis techniques in the recent years, whereas the increase in DALYs is mainly attributed to high BMI, high FPG, alcohol use, and high diet in red meat.

Multivariate analysis of independent roles of socioeconomic status, occupational physical activity, reproductive factors, and postmenopausal hormonal therapy in risk of breast cancer

PURPOSE

This case-control study assesses the independent roles of reproductive history, postmenopausal hormonal therapy (HT), socioeconomic status (SES), and occupational physical activity on the risk of breast cancer (BC).

METHODS

Odds ratios (OR) were estimated from conditional logistic multivariate regression model in a data set of 19,253 Finnish women diagnosed with BC between 1994 and 2013 and 96,265 age-matched population controls.

RESULTS

Both pre- and postmenopausal white-collar workers had significantly increased risk of ductal and lobular BC as compared to manual workers. Moderate occupational physical activity reduced risk of lobular BC by 14%. There was a transient increase in the risk of BC observed after each birth followed by a protective effect starting some years after the delivery. As the number of children increased, the short-term excess risk was lower and protective effect was observed earlier. Continuous estrogen-progestin therapy (EPT) significantly increased the risk of both ductal and lobular BC and the magnitude of risk was directly proportional to duration of use (OR for 5+ years of use 2.26, 95% confidence interval 2.12-2.42). Monthly EPT for 5+ years increased the risk (OR 1.32, 95% CI 1.20-1.45). Users of estradiol plus levonorgestrel intrauterine system devices showed ORs of 1.56 (95% CI 1.45-1.69) and 2.18 (95% CI 1.81-2.64) for ductal and lobular BC, respectively.

CONCLUSION

This study concludes that pregnancy has a dual effect on BC risk, with a transient increase in risk followed by a long-term protective effect. The SES and HT have a large effect on BC risk while occupational physical activity has only a small independent effect.

Physical activity and risk of benign proliferative epithelial disorders of the breast, in the Women's Health Initiative

BACKGROUND

Recreational physical activity (PA) has been shown to be inversely associated with breast cancer risk. However, the association of recreational PA with benign proliferative epithelial disorders (BPED) of the breast, conditions associated with increased risk of breast cancer, has not been adequately studied.

METHODS

We used data from an ancillary study of benign breast disease conducted among the 68 132 postmenopausal women (aged 50-79 at recruitment) participating in the Women's Health Initiative randomized clinical trials. All clinical trial participants underwent annual or biennial mammogram screening. During the follow-up, for women who reported breast biopsies but were cancer free, the associated histological sections were obtained and subjected to standardized central pathology review. Self-reported recreational PA at baseline (n = 61 684) and at 3 years of the follow-up (n = 55 923) were quantified as metabolic equivalents [MET]-h/week. There were 1624 confirmed BPED cases during an average follow-up time of 7.7 years. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Higher average PA over 4 years was associated with lower risk of non-atypical BPED (P-trend = 0.02). There was a 6% lower risk of non-atypical BPED for every 5 MET-h/week increase between baseline and year 3 (HR = 0.94, 95% CI 0.89-0.99). Compared with women who remained inactive (PAbaseline and PAyear3 <9 MET-h/week), those who became active (PAbaseline<9 MET-h/week to PAyear3 ≥9 MET-h/weekee), remained active (PAbaseline and PAyear3 ≥9 MET-h/week), or decreased activity (PAbaseline ≥9 MET-h/week to PAyear3 <9 MET-h/week) had lower BPED risk.

CONCLUSIONS

Recreational physical activity after menopause was associated with lower BPED risk among postmenopausal women.

Socio-demographic Determinants of Low Physical Activity in Peruvian Adults: Results of a Population-based Survey Performed in 2017-2018

Objectives

The objective of this study was to determine the prevalence of low physical activity (PA) in Peruvian adults and to identify associated factors.

Methods

An analytical study was performed using data from the 2017-2018 Nutritional Food Surveillance by Life Stages survey. The outcome variable was low PA (yes or no), assessed using the International Physical Activity Questionnaire-short form. Prevalence ratios were estimated as a measure of association.

Results

Among the 1045 persons included in the analysis, the age-standardized prevalence of low PA was 61.9%. The adjusted model showed that being female and migrating from a rural to an urban area in the last 5 years were associated with a higher probability of having low PA than males and individuals who had not migrated, while residing in rural highlands and jungle areas was associated with a reduced probability of having low PA compared to people residing in other geographic domains.

Conclusions

Being a female and migration from a rural to an urban area in the last 5 years were associated with a higher likelihood of having low PA. Therefore, promotion and prevention strategies related to PA are required, especially in the female and migrant populations.

Regulation of the Effect of Physical Activity Through MicroRNAs in Breast Cancer

Physical activity and exercise can induce beneficial molecular and biological regulations that have been associated with an incidence of various diseases, including breast cancer. Recent studies demonstrated that the potential links between physical activity-induced circulating microRNAs (miRNAs) and cancer risk and progression. Here, we investigated whether altered miRNAs by exercise could influence breast cancer progression. After primary searching in PubMed and reviewing the full-text papers, candidate miRNAs altered by exercise in breast cancer were identified. Analysis of expression profiles and clinical outcomes of altered miRNAs using The Cancer Genome Atlas datasets showed altered miRNAs expressions were significantly associated with the patient's prognosis, whereas prognostic values of each miRNA varied in different stages and subtypes. In addition, altered miRNAs profiles regulated various target genes and key signaling pathways in tumorigenesis, including pathways in cancer and the PI3K-Akt signaling pathway; however, miRNAs regulated the expression of target genes differently according to tumor stages and subtypes. These results indicate that circulating miRNAs are promising noninvasive stable biomarkers for early detection, diagnosis, prognosis, and monitoring the response to clinical therapies of breast cancer. Moreover, stages and subtype-stratified approaches for breast cancer progression would be needed to evaluate the prognostic value of miRNAs for biomarkers and therapeutic targets.

Estrogen-Receptor-Positive Breast Cancer in Postmenopausal Women: The Role of Body Composition and Physical Exercise

Breast cancer (BC) is the most commonly diagnosed cancer among women worldwide and the most common cause of cancer-related death. To date, it is still a challenge to estimate the magnitude of the clinical impact of physical activity (PA) on those parameters producing significative changes in future BC risk and disease progression. However, studies conducted in recent years highlight the role of PA not only as a protective factor for the development of ER+ breast cancer but, more generally, as a useful tool in the management of BC treatment as an adjuvant to traditional therapies. In this review, we focused our attention on data obtained from human studies analyzing, at each level of disease prevention (i.e., primary, secondary, tertiary and quaternary), the positive impact of PA/exercise in ER+ BC, a subtype representing approximately 70% of all BC diagnoses. Moreover, given the importance of estrogen receptors and body composition (i.e., adipose tissue) in this subtype of BC, an overview of their role will also be made throughout this review.

[Type-2-diabetes and cancer risk]

Type-2-diabetes (T2D) increases the risk for several cancers and cancer has become the major cause of death of T2D-patients. T2D is causally associated with colorectal, pancreatic, gallbladder, biliary, hepatocellular, gastric, esophageal, oral, breast, endometrial, ovary, kidney and thyroid cancers as well as leukemias. When T2D goes along with tobacco smoking, alcohol use, physical inactivity, excess body weight, poor diet, familial risk or certain chronic infections, the cumulative cancer risk rises, and T2D-patients often suffer from cancer disease at younger age. T2D-patients should be encouraged to join cancer screening programmes even at younger age than the average non-diabetic population.

Breast Cancer-Epidemiology, Risk Factors, Classification, Prognostic Markers, and Current Treatment Strategies-An Updated Review

Simple Summary

Breast cancer is the most common cancer among women. It is estimated that 2.3 million new cases of BC are diagnosed globally each year. Based on mRNA gene expression levels, BC can be divided into molecular subtypes that provide insights into new treatment strategies and patient stratifications that impact the management of BC patients. This review addresses the overview on the BC epidemiology, risk factors, classification with an emphasis on molecular types, prognostic biomarkers, as well as possible treatment modalities.

Abstract

Breast cancer (BC) is the most frequently diagnosed cancer in women worldwide with more than 2 million new cases in 2020. Its incidence and death rates have increased over the last three decades due to the change in risk factor profiles, better cancer registration, and cancer detection. The number of risk factors of BC is significant and includes both the modifiable factors and non-modifiable factors. Currently, about 80% of patients with BC are individuals aged >50. Survival depends on both stage and molecular subtype. Invasive BCs comprise wide spectrum tumors that show a variation concerning their clinical presentation, behavior, and morphology. Based on mRNA gene expression levels, BC can be divided into molecular subtypes (Luminal A, Luminal B, HER2-enriched, and basal-like). The molecular subtypes provide insights into new treatment strategies and patient stratifications that impact the management of BC patients. The eighth edition of TNM classification outlines a new staging system for BC that, in addition to anatomical features, acknowledges biological factors. Treatment of breast cancer is complex and involves a combination of different modalities including surgery, radiotherapy, chemotherapy, hormonal therapy, or biological therapies delivered in diverse sequences.

Physical activity domains are differently related with quality of life in breast cancer survivors: a cross-sectional study

OBJECTIVES

Treatments for breast cancer (BC) can lead to physical and mental impairments which may affect quality of life (QoL). Physical activity (PA) is highly recommended for this population due to its protective effect against BC relapse and its ability to reduce the health impact of treatment. However, it is not clear whether the different domains of PA are associated with better QoL of BC survivors. The current study aimed to verify the relationship between different PA domains with QoL of BC survivors.

METHODS

The sample consisted of 128 women BC survivors, with a mean age of 58.2 ± 9.7 years. QoL was assessed using the Short-Form Health Survey questionnaire (SF-36) and PA was verified through the Baecke questionnaire, in domains of occupation, sports practice, and leisure time/commuting. The relationship between QoL and different PA domains was verified by linear regression, adjusted by age, marital status, and socioeconomic condition.

RESULTS

Occupational PA was negatively related to physical limitations [β= -15.36 (-29.04 to -1.68] and body pain [β=-6.61 (-14.53 to 1.31) marginal association]. Sports practice was positively related to functional capacity [β= 4.24 (0.60 to 7.88)]. Leisure time/commuting PA was positively related to functional capacity [β = 7.17 (3.09 to 11.26)], vitality [β = 4.30 (0.39 to 8.22)], social aspects [β= 5.47 (0.80 to 10.15)], and mental health [β = 4.08 (0.40 to 7.75)].

CONCLUSIONS

Sports practice and leisure time/commuting PA were positively related to QoL in BC survivors, while occupational PA was negatively related to QoL, independently of age, marital status, and socioeconomic condition.

Factors for the Primary Prevention of Breast Cancer: A Meta-Analysis of Prospective Cohort Studies

Background: This report provided the effect of 15 preventable factors on the risk of breast cancer incidence.

Study design: A systematic review and meta-analysis.

Methods: A detailed research was conducted on PubMed, Web of Science, and Scopus databases in January 2020. Reference lists were also screened. Prospective cohort studies addressing the associations between breast cancer and 15 factors were analyzed. Between-study heterogeneity was investigated using the χ², τ², and I² statistics. The probability of publication bias was explored using the Begg and Egger tests and trim-and-fill analysis. Effect sizes were expressed as risk ratios (RRs) with 95% confidence intervals (CIs) using a random-effects model.

Results: Based on the results, out of 147,083 identified studies, 197 were eligible, including 19,413,702 participants. The RRs (95% CI) of factors associated with breast cancer were as follows: cigarette smoking 1.07 (1.05, 1.09); alcohol drinking 1.10 (1.07, 1.12); sufficient physical activity 0.90 (0.86, 0.95); overweight/obesity in premenopausal 0.92 (0.82, 1.03) and postmenopausal 1.18 (1.13, 1.24); nulliparity 1.16 (1.03, 1.31); late pregnancy 1.37 (1.25, 1.50); breastfeeding 0.87 (0.81, 0.93); ever using oral contraceptive 1.00 (0.96, 1.05); ever using estrogen 1.13 (1.04, 1.23); ever using progesterone 1.02 (0.84, 1.24); ever using estrogen/progesterone 1.60 (1.42, 1.80); ever taking hormone replacement therapy 1.26 (1.20, 1.32); red meat consumption 1.05 (1.00, 1.11); fruit/vegetable consumption 0.87 (0.83, 0.90); and history of radiation therapy, based on single study 1.31 (0.87, 1.98).

Conclusions: This meta-analysis provided a clear picture of several factors associated with the development of breast cancer. Moreover, the useful information in this study may be utilized for ranking and prioritizing preventable risk factors to implement effective prevention programs.

Dose-response effects of aerobic exercise on adiposity markers in postmenopausal women: pooled analyses from two randomized controlled trials

BACKGROUND/OBJECTIVE

Exercise may reduce the risk of breast cancer through adiposity changes, but the dose-response effects of exercise volume on adiposity markers are unknown in postmenopausal women. We aimed to compare the dose-response effects of prescribed aerobic exercise volume on adiposity outcomes.

PARTICIPANTS/METHODS

Data from the Alberta Physical Activity and Breast Cancer Prevention (ALPHA) and Breast Cancer and Exercise Trial in Alberta (BETA) were pooled for this analysis (N = 720). These were 12-month randomized controlled trials, where participants were randomized to 225 min/week (mid-volume) of aerobic exercise versus usual inactive lifestyle (ALPHA), or 150 min/week (low-volume) versus 300 min/week (high-volume) (BETA). Fat mass and fat-free mass were measured using DXA and intra-abdominal and subcutaneous fat area were assessed with computed tomography.

RESULTS

After 12 months of aerobic exercise, increasing exercise volumes from no exercise/control to 300 min/week resulted in statistically significant reductions in BMI, weight, fat mass, fat percentage, intra-abdominal and subcutaneous fat area (P < 0.001). Compared with controls, fat mass loss was -1.13, -1.98 and -2.09 kg in the low-, mid- and high-volume groups, respectively. Similarly, weight loss was -1.47, -1.83, -2.21 kg in the low-, mid- and high-volume groups, respectively, compared to controls, and intra-abdominal fat area loss was -7.44, -15.56 and -8.76 cm² in the low-, mid- and high-volume groups, respectively, compared to controls. No evidence for a dose-response effect on fat-free mass was noted.

CONCLUSION

A dose-response effect of exercise volume on adiposity markers was noted, however, the differences in adiposity markers were smaller when comparing 225 min/week to 300 min/week of exercise. Given the strong positive associations between obesity and postmenopausal breast cancer risk, this study provides evidence on the importance of exercise volume as part of the exercise prescription to reduce adiposity and, ultimately, postmenopausal breast cancer risk.

A Review of Modifiable Risk Factors in Young Women for the Prevention of Breast Cancer

Breast cancer is the most common cancer diagnosis in women aged less than 40 years and the second most common cause of cancer death in this age group. Global rates of young onset breast cancer have risen steadily over the last twenty years. Although young women with breast cancer have a higher frequency of underlying pathogenic mutations in high penetrance breast cancer susceptibility genes (CSG) than older women, the vast majority of young breast cancer patients are not found to have a germline CSG mutation. There is therefore a need to inform young women regarding non-genetic breast cancer risk factors which have the potential to be influenced by changes in individual behaviour. A Pubmed search was performed using the search terms “young” or “early onset”, and “breast cancer” and “modifiable risk”. Titles and abstracts from peer-reviewed publications were screened for relevance. This review presents evidence for potentially modifiable risk factors of breast cancer risk in young women, including lifestyle factors (physical activity, body habitus, alcohol use, smoking, shift work and socioeconomic factors), reproductive and hormonal factors and iatrogenic risks. The extent to which these factors are truly modifiable is discussed and interactions between genetic and non-genetic risk factors are also addressed. Health care professionals have an opportunity to inform young women about breast health and risk when presenting at a “teachable moment”, including the benefits of physical activity and alcohol habits as risk factor. More focussed discussions regarding individual personal risk and benefit should accompany conversations regarding reproductive health and take into consideration both non-modifiable and iatrogenic BC risk factors.

How does occupational physical activity influence health? An umbrella review of 23 health outcomes across 158 observational studies

OBJECTIVE

Physical activity (PA) has substantial benefits across a range of health outcomes. There is uncertainty about the PA-specific health effects, and in particular, the occupational domain. In this umbrella review, we synthesised available evidence on the associations between occupational PA (OPA) and health-related outcomes (including cancer, all-cause mortality and cardiovascular disease). This work informed the development of WHO's guidelines on PA and sedentary behaviour (2020).

DESIGN

Umbrella review of systematic reviews.

DATA SOURCE

We performed a literature search in PubMed, Web of Science, Embase, CINAHL and Sportdiscuss from database inception to 2 December 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

We included systematic reviews if they contained a quantitative assessment of OPA and its relationship with at least one health-related outcome.

RESULTS

We summarised the evidence of 17 reviews covering 23 unique health-related outcomes. We graded most evidence as low or very low, or moderate quality. We found health benefits for those engaging in high versus low OPA for multiple cancer outcomes (including colon and prostate), ischaemic stroke, coronary heart disease and mental health (ie, mental well-being and life satisfaction). High OPA was associated with unfavourable health outcomes for all-cause mortality in men, mental ill health (ie, depression and anxiety), osteoarthritis, and sleep quality and duration.

CONCLUSIONS

We found favourable associations for most health-related outcomes with high OPA levels, but we also found some evidence for unfavourable associations due to high OPA levels. At this point, there is a need for better quality evidence to provide a unequivocal statement on the health effects of OPA.

Physical Activity as an Imperative Support in Breast Cancer Management

Breast cancer (BC) is the most common malignancy and the second cause of cancer-related death among women. It is estimated that 9 in 10 cases of BC are due to non-genetic factors, and approximately 25% to 30% of total breast cancer cases should be preventable only by lifestyle interventions. In this context, physical activity represents an excellent and accessible approach not only for the prevention, but also for being a potential support in the management of breast cancer. The present review will collect the current knowledge of physical activity in the background of breast cancer, exploring its systemic and molecular effects, considering important variables in the training of these women and the evidence regarding the benefits of exercise on breast cancer survival and prognosis. We will also summarize the various effects of physical activity as a co-adjuvant therapy in women receiving different treatments to deal with its adverse effects. Finally, we will reveal the impact of physical activity in the enhancement of quality of life of these patients, to conclude the central role that exercise must occupy in breast cancer management, in an adequate context of a healthy lifestyle.

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.

Dissecting the molecular pathways involved in the effects of physical activity on breast cancers cells: A narrative review

Epidemiologic evidence suggests that obesity and sedentary are modifiable factors strongly associated with breast cancer risk worldwide. Since breast cancer represents the most frequent malignant neoplasm and the second cause of cancer-related deaths in women worldwide, an insight into the molecular mechanisms clarifying the effects of physical activity in breast cancer cells could have important implication for changing this cancer burden. In this narrative Review article, we summarize the current knowledge, regarding the effects of adapted physical activity program, focusing on the cellular signaling pathways activated and on the molecular markers involved in breast cancer. Regular exercise training in breast cancer patients has been shown to positively affect tumor-growth and survival rate. Indeed, emerging work demonstrates that regular exercise is able to affect multiple cancer hallmarks influencing the development and progression of cancer. In conclusion, changes in the circulating insulin, adipokines and estrogen levels, inflammation and oxidative stress could represent some of the possible biological mechanisms through which exercise may influence breast cancer development and recurrence.

The effect of exercise-based interventions on health-related quality of life and physical function in older patients with cancer receiving medical antineoplastic treatments: a systematic review

Older patients with cancer are underrepresented in trials investigating the effect of exercise therapy. The aim of this systematic review was to investigate the effect of exercise therapy during medical antineoplastic treatment in older patients (≥ 65 years) with cancer. A systematic review following the Cochrane guidelines was performed. Randomized controlled trials were identified through a systematic literature search in MEDLINE, EMBASE, CENTRAL, and CINAHL up to December 2019. Study selection was performed independently by two reviewers. Four randomized controlled trials published between 2014 and 2019 were included comprising a total of 412 participants. Most participants were diagnosed with breast, prostate or colorectal cancer. The studies were characterized by large differences in design, interventions and outcomes, which prevented meta-analyses. The interventions ranged from 4 weeks to 12 months and involved both supervised and unsupervised exercise programs. Some evidence of beneficial effects from the interventions were documented on physical function, muscle strength, physical activity and cognitive function. No evidence of effects was found for health-related quality of life, aerobic capacity, body composition, cancer-related symptoms and side effects, or for any clinical outcomes. No adverse events were reported. Exercise therapy seems to be safe and feasible in older patients with cancer. However, due to a limited number of studies, small sample sizes and heterogeneity across study design, the effects of exercise in older patients with cancer receiving medical antineoplastic treatment are inconclusive.