The Role of Physical Activity in Breast Cancer Etiology

doi:10.1053/j.seminoncol.2010.05.008

Seminars in Oncology

Volume 37, Issue 3, June 2010, Pages 297-302

https://doi.org/10.1053/j.seminoncol.2010.05.008 Get rights and content

Considerable research interest has been given in the past 25 years to examining the role of physical activity in breast cancer prevention given the scarcity of modifiable risk factors for this major cause of cancer incidence and mortality in women. A review of the observational epidemiologic evidence and recent randomized exercise intervention trials on the association between physical activity and breast cancer risk is presented. As of March 2010, 73 separate studies out of 91 publications worldwide were identified as having sufficient data for this review. Across these 73 studies, the average reduction in breast cancer risk, when comparing the most to the least physically active women, was 25%. There also was evidence for a dose-response effect found in the majority of studies that examined this trend. The strongest associations were found for recreational and household activities and for activity that was of at least moderate intensity and sustained over a lifetime. Within population subgroups, a stronger effect was seen in women who are normal weight, in women without a family history of breast cancer, and in women who are parous. Women of all races benefitted from physical activity; however, a particularly strong effect on breast cancer risk was observed in non-Caucasian women. Future research should focus on elucidating the exact type, dose, and timing of physical activity required to reduce breast cancer risk. Prospective observational epidemiologic studies of lifetime physical activity patterns and breast cancer risk would help in this regard, as well as randomized controlled exercise intervention trials employing hypothesized biomarkers of breast cancer risk as outcome measures. Additional consideration to the role of sedentary behavior and light-intensity activity also is needed, as well as improved physical activity assessment methods. These additional data will be useful in improving public health recommendations regarding physical activity for breast cancer risk reduction.

Section snippets

Methods

Epidemiologic studies were eligible for inclusion in this review if they included a measure of some type of physical activity and reported its association with breast cancer incidence. A review of all published literature to March 2010 was undertaken and 91 epidemiologic studies were identified.² When duplicate publications from the same study were removed, 73 individual studies remained that included 33 prospective cohort studies and 40 case-control studies. The study design, sample size,

Overall Associations Between Physical Activity and Breast Cancer Risk

Breast cancer risk was found to be decreased among women who were the most physically active compared to the least active in 29 of the 73 studies (40%) included in this review and this risk reduction was statistically significant.² In addition, eight other studies (11%) observed risk reductions for breast cancer that were of borderline statistical significance and 14 (19%) studies had risk reductions that did not achieve statistical significance. No association between physical activity and

Discussion

There is now consistent and strong evidence for an effect of physical activity on breast cancer risk reduction found in these observational epidemiologic studies. Given the limitations of these studies outlined above, arguments have been made that, for an improved understanding of the effect of exercise on breast cancer risk, randomized controlled exercise intervention trials are needed that examine the effect of different types, doses and timing of activity on risk and biomarkers involved in

Conclusion

The 73 observational epidemiologic studies included in this review have provided strong and consistent evidence that physical activity reduces breast cancer risk by about 25%. Furthermore, there is clear evidence that a dose-response effect exists with increasing levels of physical activity and decreasing risks of breast cancer. The effect of physical activity is particularly strong for household and recreational activity, for activity done later in life or sustained over a lifetime and that is

Acknowledgment

Dr Christine Friedenreich is supported by Health Senior Scholar Award from the Alberta Heritage Foundation for Medical Research. The author acknowledges Heather Neilson for critical review of the manuscript.

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Cited by (67)

Trends in physical activity research for breast cancer - A bibliometric analysis of the past ten years
2023, Heliyon
Cancer, particularly breast cancer, is a significant cause of death worldwide, and physical activity has been shown to reduce the risk of developing cancer and improve the prognosis of patients diagnosed with cancer. However, there is a lack of detailed analysis of publications related to physical activity in breast cancer patients, hindering the provision of strong evidence in this area.
The Core Collection database of Web of Science (WoS) was used as the source of the bibliography, with a search conducted on October 16, 2023. The search strategy used the terms "Physical Activity" and "Breast Cancer" or "Lymphedema," identifying articles published between 2012 and 2022. The bibliometric analysis focused on three dimensions, including scientific production and delivery, scientific collaboration, and bibliometric evaluation at the individual level. We performed the data analysis with Bibiometrix, an open-source tool integrated with R that allows a complete analysis of the behavior of the scientific literature.
A total of 979 publications related to physical activity o exercise in breast cancer (974 article, 1 data paper, 2 article early access y 2 proceedings paper), with an increasing trend in the number of articles published over the years. The most common research topics included “quality of life”, “woman”, “survivors”, and the impact of physical activity on the risk of cancer recurrence. The United States was the most productive country in this area, and the Journal "Supportive Care in Cancer” was the most common journal to publish on this topic.
This bibliometric analysis provides insight into publication trends and common research topics in the area of physical activity and breast cancer. The results can be beneficial in guiding future physical rehabilitation research inquiries and providing information to funding agencies on areas of greatest research opportunities.
Fatty acid profiles in erythrocyte membranes following the Mediterranean diet – data from a multicenter lifestyle intervention study in women with hereditary breast cancer (LIBRE)
2020, Clinical Nutrition
Citation Excerpt :
The evidence-based concepts to prevent breast cancer in this high-risk population are limited. Apart from mastectomy, lifestyle interventions comprising exercise [4] and the Mediterranean diet (MedD) have been proposed [5,6]. The MedD describes the traditional dietary pattern in southern Italy, Crete and Greece [7].
Evidence-based concepts to prevent breast cancer in women with BRCA1/2 mutations are limited. Adherence to a Mediterranean diet (MedD) has been associated with a lower risk for breast cancer, possibly due to a favorable fatty acid (FA) intake. Here, we studied in an at-risk population the effect of a lifestyle intervention that included the MedD on FA composition in red blood cell membranes (RBCM).
Data derived from the German multicenter trial LIBRE, from which 68 women were randomized into an intervention group (IG) trained for MedD and increased physical activity for 12 months, and a usual care control group (CG). Adherence to the diet was assessed after 3 and 12 months using the validated Mediterranean Diet Adherence Screener (MEDAS) and a food frequency questionnaire. RBCM FA were analyzed by gas chromatography with mass spectrometry.
The MEDAS was increased in both groups after 3 months (IG: P < 0.001; CG: P = 0.004), and remained increased only in the IG after 12 months (P < 0.001). The food frequency questionnaire revealed an increased intake of omega-3 (n-3) FA at month 3 and month 12 in the IG (both P < 0.01), but not in the CG, in which intake of energy, protein and saturated FA decreased. In both groups n-6 FA in the RBCM decreased (P < 0.001), while n-9 FA increased (P < 0.001) and n-3 FA were unchanged. Women with higher consumption of fish had higher amounts of n-3 fatty acids in the RBCM. The MEDAS was inversely correlated with n-6 fatty acids.
The RBCM FA composition was associated with dietetic parameters related to the MedD. Adherence to the MedD resulted in an altered, likely favorable FA composition. Our data suggest selected FA as biomarkers to monitor compliance to a dietetic intervention such as the MedD.
The trial is registered at ClinicalTrials.gov (reference: NCT02087592)
Exercise While Living With Breast and Gynecological Cancers
2020, Breast Cancer and Gynecologic Cancer Rehabilitation
The benefits of physical activity and exercise for the general population are well known: improved cardiopulmonary, metabolic, and psychological function just to name a few. However, it is only more recently that the role of physical activity and exercise has been explored for patients with cancer. Numerous benefits have come to light for all stages of cancer, making physical activity vital to cancer prevention, treatment, and aftercare. Exercise has a dose-dependent effect on breast cancer prevention, the proposed mechanisms being reduced adiposity, improved metabolic and hormonal balance, and reduced active and chronic inflammation. Patients who exercise better tolerate medical and surgical treatments, with less complications of treatment, higher chemotherapy completion rates, and improved outcomes. Therefore cancer patients are encouraged to strive to meet the same physical activity guidelines for healthy adults, with modifications as needed. Touted as the “new smoking,” there is mounting evidence that prolonged periods of inactivity are detrimental to our health and may increase the risk of certain cancers. Patients are thus advised to minimize sedentary behavior as well. Incorporating a combination of aerobic, resistance, balance training, bone strengthening, and flexibility training is beneficial to help maintain physical fitness and manage complications of cancer and cancer treatment. Overall, exercise has been shown to be safe for cancer patients. That said, breast and gynecological cancer patients may have preexisting conditions, or conditions related to their cancer, that warrant adherence to specific safety precautions. Medical and surgical complications of cancer treatment represent significant barriers to exercise for many patients, so not surprisingly they tend to be more sedentary than the general population. However, exercise has been shown to have beneficial effects on complications such as cancer-related fatigue, obesity and/or cachexia, osteopenia/osteoporosis, cardiotoxicity, chemo-related neurotoxicity, lymphedema, anxiety, depression, and sleep disturbances. Given the numerous positive effects of exercise on both general health and cancer-related conditions, every effort should be made to make exercise as safe and accessible as possible. Nonmedical barriers to exercise should also be addressed, including, but not limited to, reduced motivation, lack of transportation or childcare, and financial strain.
Breast cancer epidemiology
2019, Presse Medicale
Le cancer du sein est dans le monde la localisation la plus fréquente chez la femme. Cependant les incidences varient de 27/100000* en Asie Centrale-Est et en Afrique à 85–94/100000* (Australie, Amérique du Nord et Europe de l’Ouest). La France se situe parmi les fréquences les plus élevés d’Europe. Pour la plupart des pays, l’incidence augmente depuis plus de 40 ans, mais dans quelques pays (USA, Canada, Australie, France…), elle décroît depuis les années 2000–2005. Cette baisse pourrait être due à l’importante réduction des traitements hormonaux de la ménopause et pourrait être transitoire. C’est aussi la première cause de mortalité par cancer chez les femmes dans presque tous les pays, sauf dans les plus économiquement développés où elle est passée au 2ème rang, voire au 1er, après les cancers du poumon. La mortalité par cancer du sein décroît depuis, une trentaine d’années dans les pays les plus industrialisés comme en France. Diagnostic précoce et amélioration des traitements se partagent cette réussite. En France, la survie à 5 ans est de l’ordre de 88 % et de 78 % à 10 ans, elle est parmi les taux les plus élevés d’Europe de l’Ouest. L’excès de mortalité du aux cancers du sein est donc faible (< 5 %) mais variable selon l’âge, maximum les deux premières années du suivi. Plusieurs milliers d’études épidémiologiques ont été réalisées dans le monde sur les facteurs de risque des cancers du sein et il est difficile d’en tirer un bilan exhaustif. En effet les facteurs identifiés interagissent entre eux et varient selon que les cancers surviennent avant ou après la ménopause, selon leur type histologique, biologique (récepteurs) ou moléculaire. De plus leur prévalence varie d’une région à une autre et dans le temps. Le niveau de risque de la majorité de ces facteurs est ≤ 2, seuls les facteurs génétiques, la présence d’une mastopathie proliférante, un premier enfant après 35 ans et les irradiations thoraciques présentent des risques relatifs entre 2 et 5 (par comparaison les niveaux de risque liés au tabac atteignent des valeurs de 10 à 20 voir plus). Cependant, l’exposition à ces facteurs à risque ≤ 2 peut être relativement fréquente et favoriser ainsi un nombre assez conséquent de cancers du sein. L’estimation de la part attribuable (basée sur la valeur du risque et les fréquences d’exposition) permet de décider des actions de prévention primaire les plus efficientes. Dans l’ensemble des facteurs identifiés pour les cancers post-ménopausiques, seulement 35 % [23 à 45 %] de part attribuable pourrait être réduite par la prévention. Pour obtenir ce niveau de réduction on peut faire les recommandations suivantes : pour les femmes elles-mêmes : avoir un premier enfant avant l’âge de 30 ans, l’allaiter plusieurs mois, pratiquer une activité physique assez intense et régulière, éviter ou réduire le surpoids après la trentaine, ne pas s’exposer au tabagisme actif ou passif, limiter au maximum sa consommation d’alcool; pour les médecins ne pas prescrire des irradiations thoraciques inutiles (excès de mammographies en particulier), et des traitements hormonaux non justifiés.
The breast is the leading cancer site in women throughout the world. That said, breast cancer incidence varies widely, ranging from 27/100,000² (Central-East Asia and Africa) to 85–94/100,000² (Australia, North America and Western Europe). Its frequency in France is among the highest in Europe. While in most countries, its incidence has been increasing for more than 40 years, in a few other countries (USA, Canada, Australia, France…), it has been decreasing since 2000–2005. Possibly due to a substantial reduction of hormone-based treatments at menopause, the decrease may be transient. It is also the leading cause of female cancer deaths in almost all countries, with the exception of the most economically developed, in which it is currently second to lung cancer. That much said, for thirty years in highly industrialized countries such as France, breast cancer mortality has been declining. Taken together, early diagnosis and improved treatment explain this success. In France, 5-year survival and 10-year survival approximate 88 % and 78 % respectively; these rates are among the most elevated in Western Europe. Excess mortality due to breast cancer is consequently low (< 5 %) but variable according to age, and maximal during the first two years of follow-up. Several thousand epidemiological studies on risk factors for breast cancer have been carried out worldwide; it is difficult to draw up an overall assessment, especially insofar as the identified factors interact and vary according to whether the cancers occur before or after menopause and depending on their histological, biological (receptors) or molecular characteristics. Moreover, their prevalence varies in time and from one region to another. For the majority of these factors, the level of relative risk is ≤ 2. Genetic particularities: presence of proliferative mastopathy, a first child after 35 years of age and thoracic irradiation are the sole factors entailing relative risk from 2 to 5 (comparatively speaking, the risk levels associated with tobacco consumption reach values from 10 to 20, and in some cases even higher). However, exposure to risk factors ≤ 2 may be relatively frequent and consequently favorable to development of a substantial number of breast cancers. Estimation (based on degree of risk and frequency of exposure) of the proportion of risk attributable to a given factor facilitates decision-making aimed at determining the most effective primary prevention actions. Taking into consideration the identified factors pertaining to post-menopausal cancers, only 35 % [23 to 45 %] of the attributable proportions could be reduced by primary prevention. In view of achieving this level of reduction, it is possible to put forward the following recommendations: for the women themselves: have a first child before the age of 30, breastfeed for several months, engage in sufficiently intense and regular physical activity, avoid or reduce excess weight after turning thirty, avoid exposure to active or passive smoking, limit alcohol consumption; for their physicians: do not prescribe pointless thoracic irradiations (unnecessary mammography in particular) or unjustified hormonal treatments.
*persons/years.
The short-term stress response – Mother nature's mechanism for enhancing protection and performance under conditions of threat, challenge, and opportunity
2018, Frontiers in Neuroendocrinology
Citation Excerpt :
In keeping with this idea, recently conducted mouse studies have shown that exposure to short-term stress (three times per week) in a manner that mimics exercise-induced activation of short-term stress physiology, significantly enhanced anti-tumor immunity and decreased tumor burden (Dhabhar et al., 2010). These findings suggest that regular activation of the short-term stress response, in a frequency that does not induce chronic stress, may be one mechanism mediating findings from human studies showing that moderate and regular physical activity reduces the risk of cancer occurrence (Friedenreich, 2010; Friedenreich et al., 2010), progression, and mortality (Clague and Bernstein, 2012). ( 2) Intense prolonged exercise (Gleeson, 2007) or exercising under extreme environmental conditions (Walsh and Whitham, 2006), may lead to chronic exposure to stress hormones that make the individual susceptible to the deleterious health effects of chronic stress.
Our group has proposed that in contrast to chronic stress that can have harmful effects, the short-term (fight-or-flight) stress response (lasting for minutes to hours) is nature’s fundamental survival mechanism that enhances protection and performance under conditions involving threat/challenge/opportunity. Short-term stress enhances innate/primary, adaptive/secondary, vaccine-induced, and anti-tumor immune responses, and post-surgical recovery. Mechanisms and mediators include stress hormones, dendritic cell, neutrophil, macrophage, and lymphocyte trafficking/function and local/systemic chemokine and cytokine production. Short-term stress may also enhance mental/cognitive and physical performance through effects on brain, musculo-skeletal, and cardiovascular function, reappraisal of threat/anxiety, and training-induced stress-optimization. Therefore, short-term stress psychology/physiology could be harnessed to enhance immuno-protection, as well as mental and physical performance. This review aims to provide a conceptual framework and targets for further investigation of mechanisms and conditions under which the protective/adaptive aspects of short-term stress/exercise can be optimized/harnessed, and for developing pharmacological/biobehavioral interventions to enhance health/healing, and mental/cognitive/physical performance.
Predicting Quality of Life in Women with Breast Cancer Who Engage in Physical Exercise: The Role of Psychological Variables
2023, Healthcare (Switzerland)

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Cancer prevention IThe Role of Physical Activity in Breast Cancer Etiology

Section snippets

Methods

Overall Associations Between Physical Activity and Breast Cancer Risk

Discussion

Conclusion

Acknowledgment

Lower prevalence of breast cancer and cancers of the reproductive system among former college athletes compared to non-athletes

Br J Cancer

Physical activitiy and breast cancer prevention

Physical activity and cancer prevention: from observational to intervention research

Cancer Epidemiol Biomarkers Prev

American Cancer Society Guidelines on Nutrition and Physical Activity for cancer prevention: reducing the risk of cancer with healthy food choices and physical activity

CA Cancer J Clin

Cancer prevention I
The Role of Physical Activity in Breast Cancer Etiology