1
|
Stalsberg R, Darvik MD. Social Representativeness and Intervention Adherence-A Systematic Review of Clinical Physical Activity Trials in Breast Cancer Patients. Int J Public Health 2024; 69:1607002. [PMID: 38784387 PMCID: PMC11111874 DOI: 10.3389/ijph.2024.1607002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 04/10/2024] [Indexed: 05/25/2024] Open
Abstract
Objectives Representativeness in physical activity randomised controlled trials (RCT) in breast cancer patients is essential to analyses of feasibility and validity considering privileged- social groups. A step-by-step exclusion of less privileged groups through the trial process could reinforce health inequality. This study aimed at examining representativeness in breast cancer (BC) physical activity trials, investigate associations between socio-economic status (SES) and intervention adherence, and explore associations between representativeness and the relationship between SES and intervention adherence. Methods Systematic, computerised searches were performed in PubMed, CINAHL, AMED, EMBASE and PsycINFO. Additional citation-based searches retrieved 37 articles. Distributions of education level, ethnicity, and marital status in study samples were compared to national populations data to estimate representativeness in less privileged groups. Results A preponderance of studies favoured educated, married and white patients. Only six studies reported SES-adherence associations, hampering conclusions on this relationship and possible associations between representativeness and an SES-adherence relationship. Conclusion Less educated, unmarried and non-white individuals may be underrepresented in BC physical activity RCTs, while SES-adherence associations in such trials are inconclusive. Unintentional social misrepresentations may indicate that disguised inequity warrants revived attention.
Collapse
Affiliation(s)
- Ragna Stalsberg
- Department of Circulation and Medical Imaging, Norwegian University of Technology and Science (NTNU), Trondheim, Norway
| | - Monica Dahle Darvik
- Department of Neuromedicine and Movement Science, Norwegian University of Technology and Science (NTNU), Trondheim, Norway
| |
Collapse
|
2
|
Hardefeldt PJ, Penninkilampi R, Edirimanne S, Eslick GD. Physical Activity and Weight Loss Reduce the Risk of Breast Cancer: A Meta-analysis of 139 Prospective and Retrospective Studies. Clin Breast Cancer 2018; 18:e601-e612. [DOI: 10.1016/j.clbc.2017.10.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 09/21/2017] [Accepted: 10/11/2017] [Indexed: 12/17/2022]
|
3
|
Abdalla DR, Gomes BBM, Murta EFC, Michelin MA. Bone marrow-derived dendritic cells under influence of experimental breast cancer and physical activity. Oncol Lett 2017; 13:1406-1410. [PMID: 28454269 DOI: 10.3892/ol.2017.5589] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/28/2016] [Indexed: 01/17/2023] Open
Abstract
Immune cells are required in the immune response against tumours, although sometimes without success. The present study aimed to investigate dendritic cell (DC) maturation in animals with induced immunosuppression that were subjected to physical activity (PA). Immunosuppression was induced using 7,12-dimethyl-benzanthracene (DMBA). A total of 56 Balb/c mice were divided into four groups, including the control group, non-DMBA administered/PA group (GII), DMBA administered/non-PA group (GIII) and the DMBA administered/PA group (GIV). Bone marrow was removed from the leg bones following sacrifice. Bone marrow-derived DCs were stimulated to differentiate by granulocyte-macrophage colony-stimulating factor, interleukin (IL)-4 and tumour necrosis factor-α, after which the phenotype was assessed by flow cytometry and the cytokine profile was assessed using ELISAs. PA significantly increased the percentage of DCs in GII (55.38±2.63%) and GIV (50.1±3.1%) mice, as compared with GI (34.61±1.28%) and GIII (36.25±1.85%) mice (P<0.05). In addition, GIV mice showed a significantly higher level of cluster of differentiation (CD) 80+/CD86+ DCs (76.38±6.31%), as compared with GI (54.03±6.52%) and GIII (52.07±5.74%) mice (P<0.05). Furthermore, GIV mice showed a significantly higher level of CD80+/major histocompatibility complex class II double labelling (P<0.05), as compared with GIV (95.35±1.22%) and GIII (76.15±5.53%) mice. The expression of interferon-γ was significantly increased in GIV mice [5.89 (5.2-7.12)], as compared with GIII mice [2.75 (1.33-4.4)] (P<0.05). Similarly, the expression of IL-12 was markedly increased in GIV mice [1.27 (0.26-2.57)] compared with GIII mice [0.73 (0.44-1.47)], although the difference was not significant (P=0.063). The results of the present study suggested that PA was able to promote the maturation of DCs and their secretion of anti-tumour cytokines. Therefore, PA may emerge as a tool in immunotherapy.
Collapse
Affiliation(s)
- Douglas R Abdalla
- Oncology Research Institute, Federal University of the Triângulo Mineiro, Uberaba, MG 38025-180, Brazil
| | - Bruno B M Gomes
- Oncology Research Institute, Federal University of the Triângulo Mineiro, Uberaba, MG 38025-180, Brazil
| | - Eddie F C Murta
- Discipline of Gynecology and Obstetrics, Oncology Research Institute, Federal University of the Triângulo Mineiro, Uberaba, MG 38025-180, Brazil
| | - Márcia A Michelin
- Discipline of Immunology, Oncology Research Institute, Federal University of the Triângulo Mineiro, Uberaba, MG 38025-180, Brazil
| |
Collapse
|
4
|
Moderate-vigorous recreational physical activity and breast cancer risk, stratified by menopause status: a systematic review and meta-analysis. Menopause 2017; 24:322-344. [DOI: 10.1097/gme.0000000000000745] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
5
|
Hughes DC, Darby N, Gonzalez K, Boggess T, Morris RM, Ramirez AG. Effect of a six-month yoga exercise intervention on fitness outcomes for breast cancer survivors. Physiother Theory Pract 2016; 31:451-60. [PMID: 26395825 DOI: 10.3109/09593985.2015.1037409] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Yoga-based exercise has proven to be beneficial for practitioners, including cancer survivors. This study reports on the improvements in physical fitness for 20 breast cancer survivors who participated in a six-month yoga-based exercise program (YE). Results are compared to a comprehensive exercise (CE) program group and a comparison (C) exercise group who chose their own exercises. "Pre" and "post" fitness assessments included measures of anthropometrics, cardiorespiratory capacity, strength and flexibility. Descriptive statistics, effect size (d), dependent sample 't' tests for all outcome measures were calculated for the YE group. Significant improvements included: decreased % body fat (-3.00%, d = -0.44, p < 0.001); increased sit to stand leg strength repetitions (2.05, d = 0.48, p = 0.003); forward reach (3.59 cm, d = 0.61, p = 0.01); and right arm sagittal range of motion (6.50°, d = 0.92, p = 0.05). To compare YE outcomes with the other two groups, a one-way analysis of variance (ANOVA) was used. YE participants significantly outperformed C participants on "forward reach" (3.59 cm gained versus -2.44 cm lost), (p = 0.009) and outperformed CE participants (3.59 cm gained versus 1.35 cm gained), but not statistically significant. Our results support yoga-based exercise modified for breast cancer survivors as safe and effective.
Collapse
Affiliation(s)
- Daniel C Hughes
- a Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Nydia Darby
- b Nydia's Yoga Therapy , San Antonio , TX , USA
| | - Krystle Gonzalez
- c Doctor of Physical Therapy Program, School of Health Professions, University of Texas Health Science Center at San Antonio , San Antonio , TX , USA , and
| | - Terri Boggess
- d Exercise and Sport Science Department, St. Mary's University , San Antonio , TX, USA
| | - Ruth M Morris
- a Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| | - Amelie G Ramirez
- a Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio , San Antonio , TX , USA
| |
Collapse
|
6
|
Long Parma D, Hughes DC, Ghosh S, Li R, Treviño-Whitaker RA, Ogden SM, Ramirez AG. Effects of six months of Yoga on inflammatory serum markers prognostic of recurrence risk in breast cancer survivors. SPRINGERPLUS 2015; 4:143. [PMID: 25853030 PMCID: PMC4383749 DOI: 10.1186/s40064-015-0912-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 03/03/2015] [Indexed: 02/01/2023]
Abstract
Yoga-based exercise has proven to be beneficial for practitioners, including cancer survivors. This study reports on the effect on inflammatory biological markers for 20 breast cancer survivors who participated in a six-month yoga-based (YE) exercise program. Results are compared to a comprehensive exercise (CE) program group and a comparison (C) exercise group who chose their own exercises. "Pre" and "post" assessments included measures of anthropometrics, cardiorespiratory capacity, and inflammatory markers interleukin 6 (IL-6), interleukin 8 (IL-8), tumor necrosis factor alpha (TNFα) and C-reactive protein (CRP). Descriptive statistics, effect size (d), and dependent sample 't' tests for all outcome measures were calculated for the YE group. Significant improvements were seen in decreased % body fat, (-3.00%, d = -0.44, p = <.001) but not in cardiorespiratory capacity or in inflammatory serum markers. To compare YE outcomes with the other two groups, a one-way analysis of co-variance (ANCOVA) was used, controlling for age, BMI, cardiorespiratory capacity and serum marker baseline values. We found no differences between groups. Moreover, we did not see significant changes in any inflammatory marker for any group. Our results support the effectiveness of yoga-based exercise modified for breast cancer survivors for improving body composition. Larger studies are needed to determine if there are significant changes in inflammatory serum markers as a result of specific exercise modalities.
Collapse
Affiliation(s)
- Dorothy Long Parma
- />Department of Epidemiology and Biostatistics, Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio, 7411 John Smith Drive Suite 1000, San Antonio, TX USA
| | - Daniel C Hughes
- />Department of Epidemiology and Biostatistics, Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio, 7411 John Smith Drive Suite 1000, San Antonio, TX USA
| | | | - Rong Li
- />Department of Molecular Medicine, Institute of Biotechnology, University of Texas Health Science Center at San Antonio, San Antonio, TX USA
| | - Rose A Treviño-Whitaker
- />Department of Epidemiology and Biostatistics, Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio, 7411 John Smith Drive Suite 1000, San Antonio, TX USA
| | - Susan M Ogden
- />Department of Epidemiology and Biostatistics, Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio, 7411 John Smith Drive Suite 1000, San Antonio, TX USA
| | - Amelie G Ramirez
- />Department of Epidemiology and Biostatistics, Institute for Health Promotion Research, University of Texas Health Science Center at San Antonio, 7411 John Smith Drive Suite 1000, San Antonio, TX USA
| |
Collapse
|
7
|
The influence of physical activity on the profile of immune response cells and cytokine synthesis in mice with experimental breast tumors induced by 7,12-dimethylbenzanthracene. Eur J Cancer Prev 2013; 22:251-8. [DOI: 10.1097/cej.0b013e3283592cbb] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
8
|
Loprinzi PD, Cardinal BJ, Smit E, Winters-Stone KM. Physical activity and breast cancer risk. J Exerc Sci Fit 2012. [DOI: 10.1016/j.jesf.2012.04.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
|
9
|
WINTHER JF, DREYER L, OVERVAD K, TJØNNELAND A, VERDIER MGERHARDSSON. Diet, obesity and low physical activity. APMIS 2011. [DOI: 10.1111/j.1600-0463.1997.tb05614.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
10
|
Lynch BM, Neilson HK, Friedenreich CM. Physical activity and breast cancer prevention. Recent Results Cancer Res 2011; 186:13-42. [PMID: 21113759 DOI: 10.1007/978-3-642-04231-7_2] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Breast cancer is the most commonly diagnosed invasive malignancy and the second leading cause of cancer death in women. This chapter considers epidemiologic evidence regarding the association between physical activity and breast cancer risk from 73 studies conducted around the world. Across these studies there was a 25% average risk reduction amongst physically active women as compared to the least active women. The associations were strongest for recreational activity, for activity sustained over the lifetime or done after menopause, and for activity that is of moderate to vigorous intensity and performed regularly. There is also some evidence for a stronger effect of physical activity amongst postmenopausal women, women who are normal weight, have no family history of breast cancer, and are parous. It is likely that physical activity is associated with decreased breast cancer risk via multiple interrelated biologic pathways that may involve adiposity, sex hormones, insulin resistance, adipokines, and chronic inflammation. Future research should include prospective observational epidemiologic studies relating proposed biomarkers to breast cancer risk and also randomized controlled trials to examine how physical activity influences the proposed biomarkers. Exercise trials will provide more clarity regarding the appropriate type, dose, and timing of activity that relate to breast cancer risk reduction.
Collapse
Affiliation(s)
- Brigid M Lynch
- Department of Population Health Research, Alberta Health Services-Cancer Care, 1331 29 St NW, Calgary, Alberta, Canada, T2N 4N2
| | | | | |
Collapse
|
11
|
An acute exercise session increases self-efficacy in sedentary endometrial cancer survivors and controls. J Phys Act Health 2010; 7:784-93. [PMID: 21088310 DOI: 10.1123/jpah.7.6.784] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Self-efficacy can be affected by mastery experiences and somatic sensations. A novel exercise experience and associated sensations may impact self-efficacy and subsequent behaviors. We investigated the effect of a single exercise session on self-efficacy for sedentary endometrial cancer survivors compared with sedentary women of a similar age, but with no cancer history. METHODS Twenty survivors and 19 controls completed an exercise session performed as a submaximal cycle ergometry test. Sensations and efficacy were measured before and after exercise. Repeated measures analysis of variance (ANOVA) was performed. Regression models were used to determine predictors of self-efficacy and subsequent exercise. RESULTS Self-efficacy increased for both survivors and controls, but survivors had a higher rate of increase, and the change predicted subsequent exercise. The association between exercise-related somatic sensations and self-efficacy differed between the 2 groups. CONCLUSIONS A novel exercise experience had a larger effect on self-efficacy and subsequent exercise activity for endometrial cancer survivors than controls. Somatic sensations experienced during exercise may differ for survivors, which may be related to the experience of having cancer. Understanding factors affecting confidence in novel exercise experiences for populations with specific cancer histories is of the utmost importance in the adoption of exercise behaviors.
Collapse
|
12
|
Warburton DE, Charlesworth S, Ivey A, Nettlefold L, Bredin SS. A systematic review of the evidence for Canada's Physical Activity Guidelines for Adults. Int J Behav Nutr Phys Act 2010; 7:39. [PMID: 20459783 PMCID: PMC3583166 DOI: 10.1186/1479-5868-7-39] [Citation(s) in RCA: 507] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Accepted: 05/11/2010] [Indexed: 12/16/2022] Open
Abstract
This systematic review examines critically the scientific basis for Canada's Physical Activity Guide for Healthy Active Living for adults. Particular reference is given to the dose-response relationship between physical activity and premature all-cause mortality and seven chronic diseases (cardiovascular disease, stroke, hypertension, colon cancer, breast cancer, type 2 diabetes (diabetes mellitus) and osteoporosis). The strength of the relationship between physical activity and specific health outcomes is evaluated critically. Literature was obtained through searching electronic databases (e.g., MEDLINE, EMBASE), cross-referencing, and through the authors' knowledge of the area. For inclusion in our systematic review articles must have at least 3 levels of physical activity and the concomitant risk for each chronic disease. The quality of included studies was appraised using a modified Downs and Black tool. Through this search we identified a total of 254 articles that met the eligibility criteria related to premature all-cause mortality (N = 70), cardiovascular disease (N = 49), stroke (N = 25), hypertension (N = 12), colon cancer (N = 33), breast cancer (N = 43), type 2 diabetes (N = 20), and osteoporosis (N = 2). Overall, the current literature supports clearly the dose-response relationship between physical activity and the seven chronic conditions identified. Moreover, higher levels of physical activity reduce the risk for premature all-cause mortality. The current Canadian guidelines appear to be appropriate to reduce the risk for the seven chronic conditions identified above and all-cause mortality.
Collapse
Affiliation(s)
- Darren Er Warburton
- Cardiovascular Physiology and Rehabilitation Laboratory, University of British Columbia, Vancouver, Canada.
| | | | | | | | | |
Collapse
|
13
|
West-Wright CN, Henderson KD, Sullivan-Halley J, Ursin G, Deapen D, Neuhausen S, Reynolds P, Chang E, Ma H, Bernstein L. Long-term and recent recreational physical activity and survival after breast cancer: the California Teachers Study. Cancer Epidemiol Biomarkers Prev 2009; 18:2851-9. [PMID: 19843680 DOI: 10.1158/1055-9965.epi-09-0538] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Long-term physical activity is associated with lower breast cancer risk. Little information exists on its association with subsequent survival. METHODS California Teachers Study cohort members provided information in 1995-1996 on long-term (high school through age 54 years) and recent (past 3 years) participation in moderate and strenuous recreational physical activities. The 3,539 women diagnosed with invasive breast cancer after cohort entry and through December 31, 2004, were followed through December 31, 2005. Of these, 460 women died, 221 from breast cancer. Moderate and strenuous physical activities were combined into low (<or=0.50 h/wk/y of any activity), intermediate (0.51-3.0 h/wk/y of moderate or strenuous activity but no activity >3.0 h/wk/y), or high activity (>3.0 h/wk/y of either activity type). Multivariable relative risks (RR) and 95% confidence intervals (95% CI) for mortality were estimated using Cox proportional hazards methods, adjusting for race/ethnicity, estrogen receptor status, disease stage, and baseline information on comorbidities, body mass index, and caloric intake. RESULTS Women with high or intermediate levels of long-term physical activity had lower risk of breast cancer death (RR, 0.53; 95% CI, 0.35-0.80; and RR, 0.65; 95% CI, 0.45-0.93, respectively) than women with low activity levels. These associations were consistent across estrogen receptor status and disease stage, but were confined to overweight women. Deaths due to causes other than breast cancer were related only to recent activity. CONCLUSIONS Consistent long-term participation in physical activity before breast cancer diagnosis may lower risk of breast cancer death, providing further justification for public health strategies to increase physical activity throughout the lifespan.
Collapse
Affiliation(s)
- Carmen Nicole West-Wright
- Department of Population Sciences, Division of Cancer Etiology, City of Hope National Medical Center, Duarte, California 91010, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Maruti SS, Willett WC, Feskanich D, Levine B, Rosner B, Colditz GA. Physical activity and premenopausal breast cancer: an examination of recall and selection bias. Cancer Causes Control 2008; 20:549-58. [PMID: 19011977 DOI: 10.1007/s10552-008-9263-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Accepted: 10/28/2008] [Indexed: 12/22/2022]
Abstract
BACKGROUND Compared with cohort studies, case-control investigations have tended to report clearer protective associations for the relationship between physical activity and premenopausal breast cancer risk. METHODS We conducted a case-control study within the Nurses' Health Study II cohort to examine whether recall or selection bias could explain the stronger protective associations. Self-reported total recreational physical activity during adulthood and over a woman's lifetime (ages 12 years to current) were assessed in 1997 before diagnosis and, again, from one to seven years after breast cancer diagnosis among the same women. RESULTS Eighty-seven percent of cases (417 of 479) and 82% of controls (390 of 474) responded. Selection bias was observed for activity during adulthood but not for activity over a woman's lifetime. Recall bias was not observed in the direction we expected: the odds ratios (ORs) for breast cancer comparing the highest versus lowest quintile of prospectively reported total activity were not significantly different than the corresponding estimates from retrospective reports (e.g., lifetime activity: prospective OR = 0.58, 95% CI: 0.37, 0.93 versus retrospective OR = 0.80; 95% CI: 0.50, 1.29). CONCLUSION Recall or selection bias may not have been accounted for protective associations among case-control investigations examining lifetime recreational physical activity and breast cancer. Selection bias related to recreational physical activity during adulthood and random error in the measurement of physical activity remain concerns.
Collapse
Affiliation(s)
- Sonia S Maruti
- Channing Laboratory, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | | | | | | | | | | |
Collapse
|
15
|
McEachan RRC, Lawton RJ, Jackson C, Conner M, Lunt J. Evidence, theory and context: using intervention mapping to develop a worksite physical activity intervention. BMC Public Health 2008; 8:326. [PMID: 18808709 PMCID: PMC2567979 DOI: 10.1186/1471-2458-8-326] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 09/22/2008] [Indexed: 11/23/2022] Open
Abstract
Background The workplace is an ideal setting for health promotion. Helping employees to be more physically active can not only improve their physical and mental health, but can also have economic benefits such as reduced sickness absence. The current paper describes the development of a three month theory-based intervention that aims to increase levels of moderate intensity physical activity amongst employees in sedentary occupations. Methods The intervention was developed using an intervention mapping protocol. The intervention was also informed by previous literature, qualitative focus groups, an expert steering group, and feedback from key contacts within a range of organisations. Results The intervention was designed to target awareness (e.g. provision of information), motivation (e.g. goal setting, social support) and environment (e.g. management support) and to address behavioural (e.g. increasing moderate physical activity in work) and interpersonal outcomes (e.g. encourage colleagues to be more physically active). The intervention can be implemented by local facilitators without the requirement for a large investment of resources. A facilitator manual was developed which listed step by step instructions on how to implement each component along with a suggested timetable. Conclusion Although time consuming, intervention mapping was found to be a useful tool for developing a theory based intervention. The length of this process has implications for the way in which funding bodies allow for the development of interventions as part of their funding policy. The intervention will be evaluated in a cluster randomised trial involving 1350 employees from 5 different organisations, results available September 2009.
Collapse
|
16
|
O'Neill SC, Kaufman E, DeMarco T, Peshkin BN, McKenna K, Shelby R, Valdimarsdottir H, Rispoli J, Schwartz MD. Changes in Diet and Physical Activity FollowingBRCA1/2Testing. J Psychosoc Oncol 2008; 26:63-80. [DOI: 10.1080/07347330802116051] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
17
|
EMAUS AINA, VEIERØD MARITB, FURBERG ANNESOFIE, ESPETVEDT SISSI, FRIEDENREICH CHRISTINE, ELLISON PETERT, JASIENSKA GRAZYNA, ANDERSEN LARSBO, THUNE INGER. Physical Activity, Heart Rate, Metabolic Profile, and Estradiol in Premenopausal Women. Med Sci Sports Exerc 2008; 40:1022-30. [DOI: 10.1249/mss.0b013e318167411f] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Monninkhof EM, Peeters PHM, Schuit AJ. Design of the sex hormones and physical exercise (SHAPE) study. BMC Public Health 2007; 7:232. [PMID: 17767724 PMCID: PMC2031900 DOI: 10.1186/1471-2458-7-232] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2007] [Accepted: 09/04/2007] [Indexed: 11/24/2022] Open
Abstract
Background Physical activity has been associated with a decreased risk for breast cancer. The biological mechanismn(s) underlying the association between physical activity and breast cancer is not clear. Most prominent hypothesis is that physical activity may protect against breast cancer through reduced lifetime exposure to endogenous hormones either direct, or indirect by preventing overweight and abdominal adiposity. In order to get more insight in the causal pathway between physical activity and breast cancer risk, we designed the Sex Hormones and Physical Exercise (SHAPE) study. Purpose of SHAPE study is to examine the effects of a 1-year moderate-to-vigorous intensity exercise programme on endogenous hormone levels associated with breast cancer among sedentary postmenopausal women and whether the amount of total body fat or abdominal fat mediates the effects. Methods/Design In the SHAPE study, 189 sedentary postmenopausal women, aged 50–69 years, are randomly allocated to an intervention or a control group. The intervention consists of an 1-year moderate-to-vigorous intensity aerobic and strenght training exercise programme. Partcipants allocated to the control group are requested to retain their habitual exercise pattern. Primary study parameters measured at baseline, at four months and at 12 months are: serum concentrations of endogenous estrogens, endogenous androgens, sex hormone binding globuline and insuline. Other study parameters include: amount of total and abdominal fat, weight, BMI, body fat distribution, physical fitness, blood pressure and lifestyle factors. Discussion This study will contribute to the body of evidence relating physical activity and breast cancer risk and will provide insight into possible mechanisms through which physical activity might be associated with reduced risk of breast cancer in postmenopausal women. Trial registration NCT00359060
Collapse
Affiliation(s)
- Evelyn M Monninkhof
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
- Division of Public Health and Health Care, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| | - Petra HM Peeters
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Albertine J Schuit
- Division of Public Health and Health Care, National Institute for Public Health and the Environment, Bilthoven, The Netherlands
| |
Collapse
|
19
|
Monninkhof EM, Elias SG, Vlems FA, van der Tweel I, Schuit AJ, Voskuil DW, van Leeuwen FE. Physical Activity and Breast Cancer. Epidemiology 2007; 18:137-57. [PMID: 17130685 DOI: 10.1097/01.ede.0000251167.75581.98] [Citation(s) in RCA: 315] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Many epidemiologic studies have found an association between physical activity and breast cancer risk, although this has not been a consistent finding. METHODS Studies were identified through a systematic review of literature available on PubMed through February 2006. We included all cohort and case-control studies that assessed total or leisure time activities in relation to occurrence or mortality of breast cancer. The fully adjusted risk estimates and 95% confidence intervals for the highest versus lowest level of activity were documented for each study as well as evidence for a dose-response relationship. Methodologic quality was also assessed. Due to statistical and methodologic heterogeneity among studies, we did not carry out statistical pooling. To draw conclusions, we performed a best-evidence synthesis taking study quality into account. RESULTS Nineteen cohort studies and 29 case-control studies were evaluated. There was strong evidence for an inverse association between physical activity and postmenopausal breast cancer with risk reductions ranging from 20% to 80%. For premenopausal breast cancer, however, the evidence was much weaker. For pre- and postmenopausal breast cancer combined, physical activity was associated with a modest (15-20%) decreased risk. Evidence for a dose-response relationship was observed in approximately half of the higher-quality studies that reported a decreased risk. A trend analysis indicated a 6% (95% confidence interval = 3% to 8%) decrease in breast cancer risk for each additional hour of physical activity per week assuming that the level of activity would be sustained. CONCLUSIONS There is evidence for an inverse association between physical activity and breast cancer risk. The evidence is stronger for postmenopausal breast cancer than for premenopausal breast cancer.
Collapse
Affiliation(s)
- Evelyn M Monninkhof
- University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
20
|
Sorensen G, Barbeau E, Stoddard AM, Hunt MK, Kaphingst K, Wallace L. Promoting behavior change among working-class, multiethnic workers: results of the healthy directions--small business study. Am J Public Health 2005; 95:1389-95. [PMID: 16006422 PMCID: PMC1449371 DOI: 10.2105/ajph.2004.038745] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES We examined the efficacy of a cancer prevention intervention designed to improve health behaviors among working-class, multiethnic populations employed in small manufacturing businesses. METHODS Worksites were randomly assigned to an intervention or minimal-intervention control condition. The intervention targeted fruit and vegetable consumption, red meat consumption, multivitamin use, and physical activity. RESULTS Employees in the intervention group showed greater improvements for every outcome compared with employees in the control group. Differences in improvement were statistically significant for multivitamin use and physical activity. Intervention effects were larger among workers than among managers for fruit and vegetable consumption and for physical activity. CONCLUSIONS The social-context model holds promise for reducing disparities in health behaviors. Further research is needed to improve the effectiveness of the intervention.
Collapse
Affiliation(s)
- Glorian Sorensen
- Dana-Farber Cancer Institute, Center for Community-Based Research, 44 Binney St, Boston MA 02115, USA.
| | | | | | | | | | | |
Collapse
|
21
|
Carmichael AR, Bates T. Obesity and breast cancer: a review of the literature. Breast 2004; 13:85-92. [PMID: 15019686 DOI: 10.1016/j.breast.2003.03.001] [Citation(s) in RCA: 232] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2002] [Revised: 03/10/2003] [Accepted: 03/20/2003] [Indexed: 12/31/2022] Open
Abstract
A woman's build, the risk of breast cancer and its subsequent prognosis seem to be related. In most but not all case-control and prospective cohort studies, an inverse relationship has been found between weight and breast cancer among premenopausal women. However, most large epidemiological studies have found that overweight or obese women are at increased risk of developing postmenopausal breast cancer. It is suggested that higher body mass index is associated with a more advanced stage of breast cancer at diagnosis in terms of tumour size but data on lymph node status is not so consistent. All treatment modalities for breast cancer such as surgery, radiotherapy, chemotherapy and hormonal treatment may be adversely affected by the presence of obesity. The overall and disease-free survival is worse in most but not all studies of prognosis of obese pre- and postmenopausal women with breast cancer.
Collapse
Affiliation(s)
- A R Carmichael
- The Princess Royal Hospital, Haywards Heath, Sussex, UK.
| | | |
Collapse
|
22
|
Abstract
The International Agency for Research on Cancer estimates that 25% of breast cancer cases worldwide are due to overweight/obesity and a sedentary lifestyle. The preponderance of epidemiologic studies indicates that women who engage in 3-4 hours per week of moderate to vigorous levels of exercise have a 30%-40% lower risk for breast cancer than sedentary women. Women who are overweight or obese have a 50%-250% greater risk for postmenopausal breast cancer. Alcohol use, even at moderate levels (two drinks per day) increases risk for both premenopausal and postmenopausal breast cancer. Certain dietary patterns, such as high fat, low vegetables/fruits, low fiber, and high simple carbohydrates, may increase risk, but definitive data are lacking. These lifestyle factors are likely associated with breast cancer etiology through hormonal mechanisms. The worldwide trends of increasing overweight and obesity and decreasing physical activity may lead to an increasing incidence of breast cancer unless other means of risk reduction counteract these effects. Thus, adoption of lifestyle changes by individuals and populations may have a large impact on the future incidence of this disease.
Collapse
Affiliation(s)
- Anne McTiernan
- Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109-1024, USA.
| |
Collapse
|
23
|
Sorensen G, Emmons K, Hunt MK, Barbeau E, Goldman R, Peterson K, Kuntz K, Stoddard A, Berkman L. Model for incorporating social context in health behavior interventions: applications for cancer prevention for working-class, multiethnic populations. Prev Med 2003; 37:188-97. [PMID: 12914824 DOI: 10.1016/s0091-7435(03)00111-7] [Citation(s) in RCA: 169] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND This article proposes a conceptual framework for addressing social contextual factors in cancer prevention interventions, and describes work that operationalizes this model in interventions for working class, multiethnic populations. METHODS The Harvard Cancer Prevention Program Project Includes Three Studies: (1) an intervention study in 25 small businesses; (2) an intervention study in 10 health centers; and (3) a computer simulation modeling project that translates risk factor modifications into gains in life expectancy and number of cancers averted. The conceptual framework guiding this work articulates pathways by which social context may influence health behaviors, and is used to frame the interventions and guide evaluation design. RESULTS Social contextual factors cut across multiple levels of influence, and include individual factors (e.g., material circumstances, psychosocial factors), interpersonal factors (e.g., social ties, roles/responsibilities, social norms), organizational factors (e.g., work organization, access to health care), and neighborhood/community factors (e.g., safety, access to grocery stores). Social context is shaped by sociodemographic characteristics (e.g., social class, race/ethnicity, gender, age, language) that impact day-to-day realities. CONCLUSIONS By illuminating the pathways by which social contextual factors influence health behaviors, it will be possible to enhance the effectiveness of interventions aimed at reducing social inequalities in risk behaviors.
Collapse
Affiliation(s)
- Glorian Sorensen
- Center for Community-Based Research, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Yang D, Bernstein L, Wu AH. Physical activity and breast cancer risk among Asian-American women in Los Angeles: a case-control study. Cancer 2003; 97:2565-75. [PMID: 12733156 DOI: 10.1002/cncr.11364] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND To the authors' knowledge, there have been few studies published to date regarding physical activity patterns and breast cancer risk in Asian and Asian-American women. METHODS The authors conducted a population-based case-control study of 501 Asian-American women with incident breast cancer and a control group of 594 Asian-American women in Los Angeles County to evaluate the role of lifetime physical activity on breast cancer risk. Information concerning lifetime recreational physical activity (i.e., type of activity, duration [years], and frequency [average hours per week]) and occupational physical activity was obtained using a structured questionnaire that was administered in person. RESULTS Increasing years and levels (average metabolic equivalent [MET] hours per week) of lifetime recreational activity were associated with a significantly reduced risk of breast cancer after adjusting for demographic factors, migration history, and menstrual and reproductive factors. Compared with women who had no lifetime recreational physical activity, <or= 3 MET hours per week, > 3-6 MET hours per week, > 6-12 MET hours per week, and > 12 MET hours per week of activity were associated with significantly reduced risk, with odds ratios (and 95% confidence intervals) of 0.91 (0.55-1.49), 0.65 (0.39-1.10), 0.53 (0.31-0.90), and 0.47 (0.28-0.80), respectively (P value for trend < 0.001). The risk of breast cancer was associated inversely with occupational physical activity, although the result was not statistically significant. CONCLUSIONS The findings of the current study provide further support for the finding that physical activity has a protective role in breast cancer.
Collapse
Affiliation(s)
- Dongyun Yang
- Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California 90089, USA
| | | | | |
Collapse
|
25
|
Friedenreich CM, Orenstein MR. Physical activity and cancer prevention: etiologic evidence and biological mechanisms. J Nutr 2002; 132:3456S-3464S. [PMID: 12421870 DOI: 10.1093/jn/132.11.3456s] [Citation(s) in RCA: 451] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Scientific evidence is accumulating on physical activity as a means for the primary prevention of cancer. Nearly 170 observational epidemiologic studies of physical activity and cancer risk at a number of specific cancer sites have been conducted. The evidence for decreased risk with increased physical activity is classified as convincing for breast and colon cancers, probable for prostate cancer, possible for lung and endometrial cancers and insufficient for cancers at all other sites. Despite the large number of studies conducted on physical activity and cancer, most have been hampered by incomplete assessment of physical activity and a lack of full examination of effect modification and confounding. Several plausible hypothesized biological mechanisms exist for the association between physical activity and cancer, including changes in endogenous sexual and metabolic hormone levels and growth factors, decreased obesity and central adiposity and possibly changes in immune function. Weight control may play a particularly important role because links between excess weight and increased cancer risk have been established for several sites, and central adiposity has been particularly implicated in promoting metabolic conditions amenable to carcinogenesis. Based on existing evidence, some public health organizations have issued physical activity guidelines for cancer prevention, generally recommending at least 30 min of moderate-to-vigorous intensity physical activity on > or =5 d/wk. Although most research has focused on the efficacy of physical activity in cancer prevention, evidence is increasing that exercise also influences other aspects of the cancer experience, including cancer detection, coping, rehabilitation and survival after diagnosis.
Collapse
Affiliation(s)
- Christine M Friedenreich
- Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, Calgary, Alberta, Canada, T2N 1N3.
| | | |
Collapse
|
26
|
Connaughton AV, Weiler RM, Connaughton DP. Graduating medical students' exercise prescription competence as perceived by deans and directors of medical education in the United States: implications for Healthy People 2010. Public Health Rep 2002. [PMID: 12034912 DOI: 10.1016/s0033-3549(04)50038-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES This study examined perceptions of deans and directors of medical education at 128 allopathic schools of medicine in the US about the importance of physical activity and exercise topics, and their perceptions about the competence of graduating medical students to perform six fundamental skills related to exercise prescription. Healthy People 2010 recommends that clinicians counsel all patients about regular physical activity. However, in previous studies physicians identified lack of training as a barrier to physical activity counseling, and they questioned their own ability to advise patients properly. METHODS Using the 17-item Exercise and Physical Activity Competence Questionnaire, data were collected from 72 of 128 medical schools, for a response rate of 56%. RESULTS While 58% of respondents indicated their typical graduate was competent in conducting a patient evaluation for the purpose of approving that patient to begin an exercise program, only 10% said their students could design an exercise prescription. Only 6% of respondents reported that their school provided a core course addressing the American College of Sports Medicine Guidelines for Exercise Testing and Prescription. CONCLUSIONS Findings suggest a need for more undergraduate medical training in physical activity and exercise prescription.
Collapse
Affiliation(s)
- A V Connaughton
- Department of Internal Medicine, College of Medicine, University of Florida, FL 32611, USA.
| | | | | |
Collapse
|
27
|
Moradi T, Adami HO, Ekbom A, Wedrén S, Terry P, Floderus B, Lichtenstein P. Physical activity and risk for breast cancer a prospective cohort study among Swedish twins. Int J Cancer 2002; 100:76-81. [PMID: 12115590 DOI: 10.1002/ijc.10447] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The epidemiologic association between physical activity and breast cancer has been corroborated in many studies. Some inconsistencies remain, possibly due to variation in life periods for exposure assessment, confounding and undetected effect modification. In our cohort study, we address some of these questions by taking into account physical activity in different periods of life and by investigating effect modification by birth cohort and body mass index (BMI). Altogether 9,539 same-sex twin women aged 42-70 years who answered a questionnaire about their work and leisure-time physical exercise from ages 25 to 50 during 1967 and 1970 were included in our cohort. During follow-up, 506 breast cancer cases occurred through 1997. We used multivariate Cox models to estimate relative risk (RR) with 95% confidence interval (CI). We found no associations between physical activity and breast cancer overall. Women born between 1901 and 1917 (aged 51-70 at baseline) who reported regular leisure-time activity had a borderline significant 40% lower risk compared with those who reported no activity (RR 0.6; 95% CI 0.4-1.0; test for trend, p = 0.07). This association appeared to be confined to women with a low BMI after the age of 50 and to women with a high BMI during the premenopausal period. We found no evidence that work activity reduces risk for breast cancer. The importance of physical activity for breast cancer risk seems to depend on birth cohort. The association may be limited to normal-weight postmenopausal women and overweight premenopausal women.
Collapse
Affiliation(s)
- Tahereh Moradi
- Department of Medical Epidemiology, Karolinska Institutet, Stockholm, Sweden.
| | | | | | | | | | | | | |
Collapse
|
28
|
Friedenreich CM, Courneya KS, Bryant HE. Influence of physical activity in different age and life periods on the risk of breast cancer. Epidemiology 2001; 12:604-12. [PMID: 11679785 DOI: 10.1097/00001648-200111000-00005] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We conducted a population-based case-control study of 1,237 incident breast cancer cases and 1,241 controls in Alberta between 1995 and 1997 to examine the effect of physical activity performed at different ages and life periods on breast cancer risk. In this study, we measured all types of physical activity done throughout life with a questionnaire developed and tested specifically for this study. We found that breast cancer risk was most associated with a risk reduction for activity done later in life, particularly between menopause and the reference year, for which we observed an odds ratio of 0.70 (95% confidence interval = 0.52-0.95). We also stratified the study participants into four categories according to their patterns of physical activity performed before and after menopause. For the women who sustained physical activity throughout life vs those who were never active, we found an odds ratio of 0.58 (95% confidence interval = 0.41-0.83). This study suggests that sustained activity throughout life and particularly activity done later in life may have the most benefit in reducing breast cancer risk.
Collapse
Affiliation(s)
- C M Friedenreich
- Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, Edmonton, Alberta, Canada
| | | | | |
Collapse
|
29
|
Luoto R, Latikka P, Pukkala E, Hakulinen T, Vihko V. The effect of physical activity on breast cancer risk: a cohort study of 30,548 women. Eur J Epidemiol 2001; 16:973-80. [PMID: 11338130 DOI: 10.1023/a:1010847311422] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND In epidemiological studies abundant physical activity has been related to decreased breast cancer risk, though the results have been inconsistent. The purpose of this paper was to study the association of physical activity at leisure and commuting to work and incidence of breast cancer. METHODS The study cohort consisted of 30,548 female participants of the Finnish adult health behaviour survey, based on annual random samples of Finns aged 15-64, collected in 1978-1993. By the end of 1995, 332 breast cancer cases had been diagnosed in the cohort. Relative risks of breast cancer were adjusted for age at survey, body mass index (BMI), education, length of follow-up, parity and age at first birth using Poisson regression models. RESULTS Compared to women exercising less than once a week, the adjusted relative risk of breast cancer for women exercising once a week was 0.80 (95% confidence interval (CI): 0.58-1.10), for women exercising 2-3 times per week 0.92 (95% CI: 0.78-1.22) and for women exercising daily 1.01 (95% CI: 0.72-1.42). Women who reported commuting, walking or bicycling to work 30 min or more daily had slightly lower adjusted risk of breast cancer (RR: 0.87, 95% CI: 0.62-1.24) than women working at home, being unemployed or driving a car to working place. CONCLUSION Although a small protective effect of regular physical activity for breast cancer incidence was found in physical activity when commuting to work, the role of the physical activity in breast cancer prevention is still an open question.
Collapse
Affiliation(s)
- R Luoto
- National Public Health Institute, Department of Epidemiology and Health Promotion, Helsinki and Tampere School of Public Health, University of Tampere, Finland.
| | | | | | | | | |
Collapse
|
30
|
Dirx MJ, Voorrips LE, Goldbohm RA, van den Brandt PA. Baseline recreational physical activity, history of sports participation, and postmenopausal breast carcinoma risk in the Netherlands Cohort Study. Cancer 2001; 92:1638-49. [PMID: 11745243 DOI: 10.1002/1097-0142(20010915)92:6<1638::aid-cncr1490>3.0.co;2-q] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The aim of the current study was to evaluate the relation between physical activity and breast carcinoma risk with specific emphasis on interaction with other aspects of energy balance. METHODS The Netherlands Cohort Study on diet and cancer was conducted among 62,537 women ages 55-69 years at baseline. Information regarding baseline recreational physical activity, history of sports participation, and occupational physical activity was collected with a questionnaire in 1986. After 7.3 years of follow-up, 1208 incident breast carcinoma cases were available for case-cohort analyses. RESULTS A summed total of baseline recreational physical activity (including walking, cycling, gardening) showed an inverse association with breast carcinoma risk. Women who were active in the above-mentioned activities for > 90 minutes a day had a rate ratio (RR) of 0.76 (95% confidence interval [95% CI], 0.58-0.99) compared with women who were active < 30 minutes a day. Women who ever participated into sports before baseline had a RR of 1.13 (95% CI, 0.94-1.37) compared with women who never participated in sports. The relation between sports participation and breast carcinoma risk did not appear to be dependent on the time window of participation (before/after menarche, before/after birth of the first child, before/after age 20 years). No interaction was found between baseline recreational physical activity, body mass index (BMI) (kg/m(2)), energy intake, and weight gain/loss during adult life in relation to breast carcinoma, although in the subgroup of women with a high BMI we found a stronger inverse relation between recreational physical activity and breast carcinoma risk independent of energy intake. Occupational physical activity was not found to be related to breast carcinoma risk. CONCLUSIONS The current study findings support the hypothesis that recreational physical activity is associated inversely with breast carcinoma risk.
Collapse
Affiliation(s)
- M J Dirx
- Department of Epidemiology, Maastricht University, Maastricht, The Netherlands.
| | | | | | | |
Collapse
|
31
|
Friedenreich CM, Courneya KS, Bryant HE. Relation between intensity of physical activity and breast cancer risk reduction. Med Sci Sports Exerc 2001; 33:1538-45. [PMID: 11528344 DOI: 10.1097/00005768-200109000-00018] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
PURPOSE To examine the influence of frequency, duration, and intensity of physical activity on risk of breast cancer and to compare breast cancer risks associated with self-reported versus assigned intensity levels of activity. METHODS A population-based case-control study of 1233 incident breast cancer cases and 1241 controls was conducted in Alberta between 1995 and 1997. The frequency, duration and intensity of occupational, household, and recreational activities were measured throughout lifetime using the Lifetime Total Physical Activity Questionnaire and cognitive interviewing methods. Unconditional logistic regression analyses were used to estimate odds ratios and a full assessment of confounding and effect modification was undertaken. Odds ratios for self-reported and compendium-based assigned levels of activity were compared for lifetime total activity and by type of activity. RESULTS Breast cancer risk reductions were comparable when self-reported and assigned intensity values were used, although the results and trends were more evident with the assigned intensity data. Moderate-intensity occupational and household activities decreased breast cancer risk, whereas recreational activity, at any intensity level, did not contribute to a breast cancer risk reduction. CONCLUSION This study found that moderate-intensity activities were the major contributors to the decrease in breast cancer risk found in this study and that risk reductions were more evident when the frequency and duration of activity alone were modeled. Of the three types of activity considered, the greatest risk reductions observed were for occupational and household activities.
Collapse
Affiliation(s)
- C M Friedenreich
- Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, Calgary, Alberta, Canada.
| | | | | |
Collapse
|
32
|
Thune I, Furberg AS. Physical activity and cancer risk: dose-response and cancer, all sites and site-specific. Med Sci Sports Exerc 2001; 33:S530-50; discussion S609-10. [PMID: 11427781 DOI: 10.1097/00005768-200106001-00025] [Citation(s) in RCA: 290] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE The association between physical activity and overall and site-specific cancer risk is elaborated in relation to whether any observed dose-response association between physical activity and cancer can be interpreted in terms of how much physical activity (type, intensity, duration, frequency) is needed to influence site- and gender-specific cancer risk. METHODS Observational studies were reviewed that have examined the independent effect of the volume of occupational physical activity (OPA) and/or leisure time physical activity (LPA) on overall and site-specific cancer risk. RESULTS The evidence of cohort and case-control studies suggests that both leisure time and occupational physical activity protect against overall cancer risk, with a graded dose-response association suggested in both sexes. Confounding effects such as diet, body weight, and parity are often included as a covariate in the analyses, with little influence on the observed associations. A crude graded inverse dose-response association was observed between physical activity and colon cancer in 48 studies including 40,674 colon/colorectal cancer cases for both sexes. A dose-response effect of physical activity on colon cancer risk was especially observed, when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed as MET-hours per week. An observed inverse association with a dose-response relationship between physical activity and breast cancer was also identified in the majority of the 41 studies including 108,031 breast cancer cases. The dose-response relationship was in particular observed in case-control studies and supported by observations in cohort studies when participation in activities of at least moderate activity (>4.5 MET) and demonstrated by activities expressed by MET-hours per week. This association between physical activity and breast cancer risk is possibly dependent on age at exposure, age at diagnosis, menopausal status and other effect modifiers, e.g., body mass index. Furthermore, data concerning carcinoma of other cancers (prostate, lung, endometrium, ovary, and testicular cancers) are required. CONCLUSION A protective effect of physical activity on site-specific cancer risk with a dose-response association between physical activity and colon and pre- and postmenopausal breast cancer supported by identified biological mechanisms has been observed. The optimal permutation of type, intensity, duration, and frequency of physical activity across the lifespan is unclear, but it is gender, age, and site specific and supports moderate activity (>4.5 MET) more than light activities (<4.5 MET). The complicated nature of the physical activity variable, combined with lack of knowledge regarding possible biological mechanisms operating between physical activity and cancer, warrants further studies including controlled clinical randomized trials.
Collapse
Affiliation(s)
- I Thune
- Institute of Community Medicine, Faculty of Medicine, University of Tromsø, N-9037 Tromsø, Norway.
| | | |
Collapse
|
33
|
|
34
|
Pedersen BK, Hoffman-Goetz L. Exercise and the immune system: regulation, integration, and adaptation. Physiol Rev 2000; 80:1055-81. [PMID: 10893431 DOI: 10.1152/physrev.2000.80.3.1055] [Citation(s) in RCA: 946] [Impact Index Per Article: 39.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Stress-induced immunological reactions to exercise have stimulated much research into stress immunology and neuroimmunology. It is suggested that exercise can be employed as a model of temporary immunosuppression that occurs after severe physical stress. The exercise-stress model can be easily manipulated experimentally and allows for the study of interactions between the nervous, the endocrine, and the immune systems. This review focuses on mechanisms underlying exercise-induced immune changes such as neuroendocrinological factors including catecholamines, growth hormone, cortisol, beta-endorphin, and sex steroids. The contribution of a metabolic link between skeletal muscles and the lymphoid system is also reviewed. The mechanisms of exercise-associated muscle damage and the initiation of the inflammatory cytokine cascade are discussed. Given that exercise modulates the immune system in healthy individuals, considerations of the clinical ramifications of exercise in the prevention of diseases for which the immune system has a role is of importance. Accordingly, drawing on the experimental, clinical, and epidemiological literature, we address the interactions between exercise and infectious diseases as well as exercise and neoplasia within the context of both aging and nutrition.
Collapse
Affiliation(s)
- B K Pedersen
- Department of Infectious Diseases and Copenhagen Muscle Research Centre, University of Copenhagen, Copenhagen, Denmark.
| | | |
Collapse
|
35
|
Moore DB, Folsom AR, Mink PJ, Hong CP, Anderson KE, Kushi LH. Physical activity and incidence of postmenopausal breast cancer. Epidemiology 2000; 11:292-6. [PMID: 10784246 DOI: 10.1097/00001648-200005000-00011] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Whether physical activity reduces the risk of postmenopausal breast cancer is uncertain; few studies have addressed this issue. We examined the association of leisure physical activity with breast cancer incidence among 37,105 postmenopausal participants in the Iowa Women's Health Study. Women reporting the highest level of physical activity at baseline compared with women with the lowest level of activity had an age-adjusted relative risk of breast cancer of 0.92 (95% confidence interval = 0.80-1.05). Women reporting any regular leisure-time physical activity had a relative risk of 0.97 (95% confidence interval = 0.87-1.08) compared with those reporting no such regular physical activity. Adjustment for potential confounders did not appreciably alter the findings. There is little evidence from this study that physical activity later in life is associated to any appreciable extent with breast cancer incidence.
Collapse
Affiliation(s)
- D B Moore
- Division of Epidemiology, University of Minnesota School of Public Health, Minneapolis 55454-1015, USA
| | | | | | | | | | | |
Collapse
|
36
|
Verloop J, Rookus MA, van der Kooy K, van Leeuwen FE. Physical activity and breast cancer risk in women aged 20-54 years. J Natl Cancer Inst 2000; 92:128-35. [PMID: 10639514 DOI: 10.1093/jnci/92.2.128] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND/METHODS Although several studies have suggested that physical activity is associated with a decreased risk of breast cancer, such a decrease has not been found consistently, perhaps because physical activity was assessed in different ways and for restricted periods. Few studies have assessed the risk of breast cancer in relation to lifetime physical activity. We used data from a population-based, case-control study, including 918 case subjects (aged 20-54 years) and 918 age-matched population control subjects, to examine associations between breast cancer risk and physical activity at ages 10-12 years and 13-15 years, lifetime recreational activity, and title of longest held job. RESULTS Women who were more active than their peers at ages 10-12 years had a lower risk of breast cancer (odds ratio [OR] = 0.68; 95% confidence interval [CI] = 0.49-0.94). Women who had ever engaged in recreational physical activity had a reduced risk of breast cancer compared with inactive women (OR = 0.70; 95% CI = 0.56-0.88). Neither very early recreational activity (before age 20 years) nor recent activity (last 5 years) was associated with a greater reduction in risk than recreational activity in the intermediate period. Furthermore, women who started recreational activities after age 20 years and women who started earlier and continued their activities throughout adult life experienced a similar reduction in risk. Lean women, i.e., women with a body mass index (weight in kg/[height in m](2)) less than 21. 8 kg/m(2), appeared to have a lower risk associated with recreational physical activity than women with a body mass index greater than 24.5 kg/m(2) (OR = 0.57 [95% CI = 0.40-0.82] and OR = 0. 92 [95% CI = 0.65-1.29], respectively). CONCLUSIONS Our findings support the hypothesis that recreational physical activity is associated with a decreased risk of breast cancer. Physical activity in early or recent life does not appear to be associated with additional beneficial effects.
Collapse
Affiliation(s)
- J Verloop
- Department of Epidemiology, The Netherlands Cancer Institute, Amsterdam
| | | | | | | |
Collapse
|
37
|
Rissanen A, Fogelholm M. Physical activity in the prevention and treatment of other morbid conditions and impairments associated with obesity: current evidence and research issues. Med Sci Sports Exerc 1999; 31:S635-45. [PMID: 10593540 DOI: 10.1097/00005768-199911001-00024] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the current status of knowledge concerning the effects of physical activity in the treatment and prevention of obesity- related problems, including cancers of the colon, breast, uterus, and prostate; gallstones; osteoarthritis; back pain; sleep apnea; reproductive abnormalities; and impaired health-related quality of life. DESIGN A Medline literature search on the effects of physical activity in the above conditions was conducted. Only studies with some measure of weight and a description of the type of physical activity were included. RESULTS No controlled randomized trials of exercise in the treatment of any of the studied conditions in obese patients were identified. Most of the epidemiologic studies reviewed were beset with severe methodological weaknesses. Most of the 18 studies on physical activity and colon cancer risk showed a protective effect that in some studies appeared to be greater than expected by weight loss alone. Some but not all studies of hormone-dependent cancers and gallstones showed a protective effect for physical activity. There were insufficient data on the role of exercise for the other morbid conditions studied. CONCLUSION The scarce data available on the role of physical activity in the prevention of obesity-related chronic conditions listed above suggest a protective role that needs to be examined further in studies with improved methodologies. Well-designed intervention trials are needed to assess the role of physical activity in the treatment and long-term outcome of obese patients with these co-morbid conditions.
Collapse
Affiliation(s)
- A Rissanen
- Helsinki University Central Hospital, Finland.
| | | |
Collapse
|
38
|
Emmons KM, Linnan LA, Shadel WG, Marcus B, Abrams DB. The Working Healthy Project: a worksite health-promotion trial targeting physical activity, diet, and smoking. J Occup Environ Med 1999; 41:545-55. [PMID: 10412096 DOI: 10.1097/00043764-199907000-00003] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Worksites are a key channel for delivery of interventions designed to reduce chronic disease among adult populations. Although some evaluations of worksite physical-activity interventions have been conducted, to date very few randomized trials of worksite health promotion have included the goal of increasing physical-activity levels as part of a comprehensive multiple risk factor approach to worksite health promotion. This article presents the results regarding behavior change found among the cohort of 2055 individuals who completed three health-behavior assessments as part of their worksites' participation in The Working Healthy Project (WHP), a multiple risk factor intervention implemented in 26 manufacturing worksites. In this study, a randomized matched-pair design was used. Fifty-one percent (n = 2,761) of the employees who completed the baseline assessment also completed the interim survey. Eighty-three percent of those who completed the interim assessment also completed the final survey. The WHP intervention targeted smoking, nutrition, and physical activity. At baseline, 38% of the sample reported engaging in regular exercise, and subjects reported consuming an average of 2.7 servings of fruits and vegetables per day, 7.9 grams of fiber per 1000 kilocalories, and 35.4% calories from fat per day; 28% of the sample were smokers. By the time of both the interim (intervention midpoint) and final (end of intervention) assessments, participants in the intervention condition had significantly increased their exercise behavior, compared with the control condition. There was also increased consumption of fruits and vegetables and fiber in the intervention condition by the time of the final assessment, compared with the control condition. No differences by condition were found with regard to percentage of calories from fat consumed or smoking cessation. These results suggest that among a cohort of participants in a worksite health promotion study, there were significant health behavior changes across two risk factors over time. These data suggest that further investigation of multiple risk factor worksite health promotion is warranted, particularly with a focus on ways to increase participation in these programs and to diffuse intervention effects throughout the entire workforce.
Collapse
Affiliation(s)
- K M Emmons
- Miriam Hospital/Brown University Medical School, Providence, RI, USA
| | | | | | | | | |
Collapse
|
39
|
Zahm SH, Hoffman-Goetz L, Dosemeci M, Cantor KP, Blair A. Occupational physical activity and non-Hodgkin's lymphoma. Med Sci Sports Exerc 1999; 31:566-71. [PMID: 10211853 DOI: 10.1097/00005768-199904000-00012] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE The purpose of this study was to evaluate the role of physical activity in the development of non-Hodgkin's lymphoma (NHL). METHODS Incident NHL cases and population-based controls were identified from three case-control studies conducted in four midwestern states: Iowa, Kansas, Minnesota, and Nebraska. A total of 1177 cases (993 men, 184 women) and 3625 controls (2918 men, 707 women) were interviewed. Usual occupation (all states) and lifetime occupational histories (Iowa and Minnesota only), obtained from interviews, were classified for energy expenditure (EE) and sitting time. Odds ratios (OR) and 95% confidence intervals were calculated comparing moderate and high activity levels with sedentary levels. RESULTS There was no evidence of an association between NHL and occupational physical activity measured either by EE or sitting time. Among men, the OR associated with usual occupation moderate and high EE were 1.1 and 1.0, respectively. For sitting time, the OR were also 1.1 and 1.0 for moderate and high activity, respectively. Among women, slight nonsignificant elevations in risk of NHL were observed among the high energy level and high activity sitting categories. The trends were not significant. There was no evidence of confounding or effect modification by vital status, hair dye use, or solvent exposure. Among subjects with lifetime occupational histories, there were no significant increases or trends for cumulative or average EE or sitting time. There was no association between occupational physical activity and NHL. CONCLUSION Research on nonoccupational physical activity, which in the U.S. is likely the more important component of daily activity than occupational activity, may still be warranted given the laboratory evidence linking physical activity and immune function, an important factor in the etiology of NHL.
Collapse
Affiliation(s)
- S H Zahm
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA
| | | | | | | | | |
Collapse
|
40
|
Winett RA, Anderson ES, Whiteley JA, Wojcik JR, Rovniak LS, Graves KD, Galper DI, Winett SG. Church-based health behavior programs: Using social cognitive theory to formulate interventions for at-risk populations. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0962-1849(99)80004-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
41
|
Latikka P, Pukkala E, Vihko V. Relationship between the risk of breast cancer and physical activity. An epidemiological perspective. Sports Med 1998; 26:133-43. [PMID: 9802171 DOI: 10.2165/00007256-199826030-00001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The possible protective effect of physical exercise on the risk of breast cancer has gained attention during the last few years. According to the current concepts of biological mechanisms underlying the possible protection, physical activity may alter menstrual function by reducing the number of ovulatory menstrual cycles via a hormone-related pathway and, thus, reducing the cumulative exposure to progesterone and estrogen. Experimental studies on the effects of exercise suggest changes in menstrual characteristics and in ovarian hormone serum levels. The majority of epidemiological studies, in spite of limitations in estimating physical activity and partly incomplete control of confounding factors, suggest a protective effect of physical activity. Whether physical activity offers a means of primary prevention of breast cancer is still an open issue.
Collapse
Affiliation(s)
- P Latikka
- LIKES-Research Center, Jyväskylä, Finland.
| | | | | |
Collapse
|
42
|
Thorand B, Kohlmeier L, Simonsen N, Croghan C, Thamm M. Intake of fruits, vegetables, folic acid and related nutrients and risk of breast cancer in postmenopausal women. Public Health Nutr 1998; 1:147-56. [PMID: 10933412 DOI: 10.1079/phn19980024] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE To determine the role of fruit and vegetable consumption and dietary intake of folic acid and related nutrients such as methionine, cysteine and alcohol in the aetiology of breast cancer. DESIGN Population based case-control study. SETTING Part of the European Community Multicentre Study on Antioxidants, Myocardial Infarction, and Cancer of the Breast (EURAMIC) in Berlin, Germany. SUBJECTS As part of the EURAMIC study, dietary intake data were collected in 43 postmenopausal women diagnosed with breast cancer between 1991 and 1992 in Berlin, Germany, and compared to 106 population-based controls. RESULTS Odds ratios (ORs) adjusted for major risk factors of breast cancer but not for total energy intake showed a non-significant inverse association between a high intake of vegetables (OR=0.76, 95% CI=0.48-1.20) and fruits (OR=0.74, 95% CI=0.48-1.15) and breast cancer. Once results were adjusted for total energy intake the associations became much weaker (vegetables: R=0.86, 95% CI=0.51-1.46; fruits: OR=0.82, 95% CI=0.51-1.32). For all nutrients, the effect of energy adjustment was more profound and the inverse associations disappeared when results were adjusted for energy intake (total folate-not energy adjusted: OR = 0.79, 95% CI=0.51-1.21; energy adjusted: OR=1.14, 95% CI=0.73-1.79; folate equivalents-not energy adjusted: OR=0.81, 95% CI=0.53-1.23; energy adjusted: OR=1.16, 95% CI=0.78-1.74; methionine-not energy adjusted: OR=0.60, 95% CI=0.35-1.03; energy adjusted: OR=1.29, 95% CI=0.76-2.19; cysteine-not energy adjusted: OR=0.52, 95% CI=0.29-0.94; energy adjusted: OR=1.22, 95% CI=0.75-1.97). Alcohol intake was inversely associated with breast cancer in a non-significant way, possibly due to the relatively low alcohol intake of the study population. CONCLUSIONS The results of this study do not provide firm evidence that a high intake of fruits and vegetables, folic acid, methionine or cysteine reduces the risk of getting breast cancer.
Collapse
Affiliation(s)
- B Thorand
- Department of Epidemiology, School of Public Health, University of North Carolina at Chapel Hill, 27599-7400, USA
| | | | | | | | | |
Collapse
|
43
|
Rockhill B, Willett WC, Hunter DJ, Manson JE, Hankinson SE, Spiegelman D, Colditz GA. Physical Activity and Breast Cancer Risk in a Cohort of Young Women. J Natl Cancer Inst 1998. [DOI: 10.1093/jnci/90.15.1555] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
|
44
|
Friedenreich CM, Thune I, Brinton LA, Albanes D. Epidemiologic issues related to the association between physical activity and breast cancer. Cancer 1998. [DOI: 10.1002/(sici)1097-0142(19980801)83:3+<600::aid-cncr2>3.0.co;2-b] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
45
|
|
46
|
Abstract
Evidence has been accumulating that suggests that physical activity may help reduce the risk of cancer. Physically active people have been shown to have a decreased rate of all-cancer mortality. The incidence of colon, breast, and perhaps prostate cancer are decreased in more active people when compared with their sedentary peers. Chronic physical activity may decrease tumor risk by its effect on natural immunity, antioxidant defenses, improved energy balance, hormonal changes, or by other unknown mechanisms.
Collapse
Affiliation(s)
- R B Kiningham
- Department of Family Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109-0707, USA
| |
Collapse
|
47
|
Gammon MD, John EM, Britton JA. Recreational and occupational physical activities and risk of breast cancer. J Natl Cancer Inst 1998; 90:100-17. [PMID: 9450570 DOI: 10.1093/jnci/90.2.100] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Physical activity has been hypothesized to reduce breast cancer risk, but an inverse association has not been consistently reported. In this review, we critically evaluate for coherence, validity, and bias the epidemiologic studies on recreational or occupational physical activity, discuss the biologic plausibility of the association, and identify areas for future research. Results from seven of nine studies suggest that higher levels of occupational physical activity may be associated with a reduction in risk, at least among a subgroup of women. Eleven of 16 investigations on recreational exercise reported a 12%-60% decrease in risk among premenopausal and postmenopausal women, although a dose-response trend was not evident in most of the studies. The reduction in risk associated with exercise was more likely to be observed in case-control studies than in cohort studies. Most investigations incompletely assessed physical activity, which contributed to conflicting findings on the optimal time period, duration, frequency, or intensity of activity to minimize risk. Physical activity may exert its effects through changes in menstrual characteristics, reduced body size, or alterations in immune function. In summary, most epidemiologic studies of physical activity reported a reduction in the risk of breast cancer among physically active women. Future research studies should focus on using a cohort design to rule out recall bias as a possible explanation for the decrease in risk associated with exercise, on improving assessment of lifetime physical activity from all sources to clarify whether there is a dose-response relation or an optimal time period, duration, frequency, or intensity of activity, and on elucidating the underlying mechanisms for the inverse association.
Collapse
Affiliation(s)
- M D Gammon
- Columbia University School of Public Health, Division of Epidemiology, New York, NY 10032, USA
| | | | | |
Collapse
|
48
|
Weisburger JH. Dietary fat and risk of chronic disease: mechanistic insights from experimental studies. JOURNAL OF THE AMERICAN DIETETIC ASSOCIATION 1997; 97:S16-23. [PMID: 9216563 DOI: 10.1016/s0002-8223(97)00725-6] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The primary nutritionally linked diseases are coronary heart disease, stroke and cancers of the stomach, colon, pancreas, prostate, breast, ovary, and endometrium. Dietary fats operate through a promoting mechanism. An S-shaped dose-response curve with a threshold has been demonstrated in models of breast and colon cancer in which the standard Western fat intake of 40% of energy yields a high level of promotion, and reduction of fat to 10% to 20% of energy (the traditional Japanese fat intake) has a low promoting action. In models of breast and colon cancer, saturated fats such as beef fat or lard, and monounsaturated oils, such as olive oil, display only a weak promoting effect, with the incidence of induced tumors being similar at intake levels of 40% and 10% of energy. On the other hand, the n-6-polyunsaturated oils display a strong promoting effect. Such findings may have a parallel in the low but definitely increasing slope of postmenopausal breast cancer incidence in the past 30 years as the American public decreased saturated fat intake to avoid heart disease and increased use of the n-6-polyunsaturated oils. Mechanisms underlying the cancer-promoting effect in the colon stem from increased hepatic production of bile acids, which are transferred to the intestinal tract via the bile. Ingestion of 40% fat calories yields higher concentrations of bile acids in the colon than lower levels of dietary fat ingestion. Cancer in the mammary gland is promoted through higher concentrations of fats and phospholipids in the gland as well as increased levels of estrogen secondary to production by the ovary and other endocrine tissues that, in turn, affect the generation of pituitary hormones such as prolactin and growth hormone. The n-3-fats, as found in fish and fish oils, have a pronounced inhibitory effect in models of colon and breast cancer, presumably through their shifting of prostaglandin metabolism to the generation of prostaglandins, which lower cell proliferation potential and, thus, decrease promotional effects. The role of dietary fat as a promoter can be modified by other nutritional components. Finally, one of the best pieces of evidence for an enhancing effect of many dietary fats in the nutritionally linked cancers is the current increase in the incidence of these diseases in Japan as the nutritional habits of people in that country become more Westernized.
Collapse
|
49
|
Abstract
BACKGROUND Because physical activity may affect hormonal concentrations and energy balance, we decided to investigate whether everyday exercise is related to the risk of breast cancer. METHODS During 1974 to 1978 and 1977 to 1983, a total of 25,624 women, 20 to 54 years of age at entry, enrolled in health surveys and answered questionnaires about leisure-time and work activity. RESULTS During a median follow-up of 13.7 years, we identified 351 cases of invasive breast cancer among the 25,624 women in the cohort. Greater leisure-time activity was associated with a reduced risk of breast cancer, after adjustments for age, body-mass index (the weight in kilograms divided by the square of the height in meters), height, parity, and county of residence (relative risk, 0.63; 95 percent confidence interval, 0.42 to 0.95), among women who exercised regularly, as compared with sedentary women (P for trend=0.04). In regularly exercising women, the reduction in risk was greater in premenopausal women than in postmenopausal women, and greater in younger women (<45 years at study entry) than in older women (> or =45 years) (relative risk, 0.38; 95 percent confidence interval, 0.19 to 0.79). In stratified analyses the risk of breast cancer was lowest in lean women (body-mass index, <22.8) who exercised at least four hours per week (relative risk, 0.28; 95 percent confidence interval, 0.11 to 0.70). The risk was also reduced with higher levels of activity at work, and again there was a more pronounced effect among premenopausal than postmenopausal women. CONCLUSIONS Physical activity during leisure time and at work is associated with a reduced risk of breast cancer.
Collapse
Affiliation(s)
- I Thune
- The Institute of Community Medicine, University of Tromsø, Norway
| | | | | | | |
Collapse
|
50
|
Abstract
The identification of genetic mutations thought to be directly responsible for the development of breast cancer represents a major advance in our understanding of this disease. Mutations in BRCA1 and BRCA2 are thought to be responsible for the majority of inherited breast cancer. Although these mutations account for approximately 5% of breast cancer cases, the identification of these genes will have a profound impact on the way patients and their physicians view breast cancer risk. Genetic testing for BRCA1 and BRCA2 mutations is already available. Interpreting results of genetic tests for these mutations is problematic and the clinical management of women carrying these gene mutations is far from straightforward. The purpose of this paper is to review recent developments in the genetic aspects of breast cancer, including genetic testing, to critically review risk factor modification, and to discuss screening and potential prophylactic measures.
Collapse
Affiliation(s)
- M A Warmuth
- Division of Hematology and Medical Oncology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | | |
Collapse
|