This summary table contains detailed information about research studies. Summary tables offer an informative look at the science behind many breast cancer guidelines and recommendations. However, they should be viewed with some caution. In order to read and interpret research tables successfully, it is important to understand some key concepts. Learn how to read a research table.
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Introduction: Physical activity may lower the risk of breast cancer. Most case-control studies have found a decreased risk of breast cancer in women who are the most active (studies not shown). However, findings from cohort studies have been mixed (see table below).
When the evidence is looked at as a whole, regular physical activity seems to moderately protect against breast cancer. This is seen most clearly in postmenopausal women [1].
Learn about the strengths and weaknesses of different types of studies.
See how this risk factor compares with other risk factors for breast cancer.
Study selection criteria: Prospective cohort studies with at least 500 breast cancer cases.
Table notes: Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk.
MET (metabolic equivalent) hours are often used as a unit of measure for physical activity. One MET hour is equal to the energy used to sit quietly for one hour. Different types of activity have different MET scores. For example, walking is 3 MET hours and swimming is 7 MET hours. Moderate activities, like mowing the lawn or slow dancing, range from 3-6 MET hours and vigorous activities, like playing tennis or jogging, score higher than 6 MET hours.
Study
|
Study Population
(number of participants)
|
Follow-up
(years)
|
Levels of Activity Compared
|
Relative Risk of Breast Cancer in Physically Active Women Compared with Inactive Women, RR (95% CI)
|
Pre-menopausal
|
Post-menopausal
|
Pre- and post-menopausal combined
|
Prospective cohort studies
|
NIH-AARP Diet and Health Study [2,3]
|
182,862
(6,609 cases)
|
7
|
At least 20 min activity at least 5 times/wk
vs.
inactive
|
|
0.92
(0.85-1.00)*
|
|
Nurses' Health Study [4]
|
95,396
(4,782 cases)
|
20
|
27 or more
vs.
less than 3 MET hr/wk
|
|
0.88
(0.79-0.98)
|
|
French E3N cohort [5]
|
90,509
(3,424 cases)
|
11.4
|
22.3-33.8 MET hrs/wk recreational activity
vs.
inactive
|
|
|
0.88
(0.79-0.98)
|
| |
|
|
33.8 or more MET hrs/wk recreational activity
vs.
inactive
|
|
|
0.81
(0.72-0.92)
|
EPIC [6]
|
218,169
(3,423 cases)
|
6.4
|
At least 42
vs.
less than 14 MET hrs/wk of recreational activity
|
0.94
(0.76-1.15)
|
0.96
(0.85-1.08)
|
|
California Teachers Study [7]
|
110,599
(2,649 cases)
|
6.6
|
5 or more hrs/wk moderate physical activity
vs.
inactive
|
|
|
1.03
(0.88-1.19)†
|
Iowa Women’s Health Study [8]
|
36,363
(2,548 cases)
|
15.3
|
High level of activity
vs.
low level
|
|
0.91
(0.82-1.01)
|
|
National Breast Cancer Screening Study-Canada [9]
|
40,318
(2,545 cases)
|
16.4
|
At least 1 hr/day vigorous physical activity
vs.
inactive
|
0.87
(0.68-1.09)
|
1.00
(0.78-1.29)
|
0.93
(0.78-1.10)
|
Cancer Prevention Study II (CPS II) [10]
|
72,608
(1,520 cases)
|
5
|
At least 42
vs.
less than 7 MET hrs/wk
|
|
0.71
(0.49-1.02)
|
|
Norwegian-Swedish Women’s Lifestyle and Health Cohort Study [11]
|
99,504
(1,166 cases)
|
9.1
|
Vigorous activity
vs.
no activity
|
1.24
(0.85-1.82)‡
|
|
|
Women’s Health Initiative [12]
|
74,171
(1,780 cases)
|
4.7
|
Equivalent of walking 1.25-2.5 hrs/wk
vs.
inactive
|
|
0.82
(0.68-0.97)
|
|
Breast Cancer Detection Demonstration Project Follow-up Study [13]
|
32,269
(1,506 cases)
|
8.4
|
Higher
vs.
lower level of activity |
|
0.87
(0.74-1.02)
|
|
Netherlands Cohort Study [14]
|
62,537
(1,208 cases)
|
7.3
|
More than 90 minutes/day of activity
vs.
less than 30 minutes/day
|
|
0.76
(0.58-0.99)
|
|
U.S. Radiologic Technologies cohort [15]
|
45,631
(864 cases)
|
8.9
|
At least 97
vs.
less than 9.5 MET hrs/wk
|
|
|
0.91
(0.74-1.13)
|
| |
|
|
Walking/hiking at least 10 hrs/wk
vs.
never walking/hiking
|
|
|
0.57
(0.34-0.95)
|
Nurses’ Health Study II [16,17]
|
110,468
(849 cases)
|
10
|
27 or more
vs.
less than 3 MET hrs/wk
|
1.04
(0.82-1.33)§
|
|
|
PLCO Cancer Screening Trial [18]
|
27,541
(764 cases)
|
4.9
|
3 hrs/wk recreational activity
vs.
inactive
|
|
1.02
(0.79-1.30)
|
|
| |
|
|
4 or more hrs/wk recreational activity
vs.
inactive
|
|
0.78
(0.61-0.99)
|
|
Japan Public Health Center-based Prospective Study [19]
|
53,578
(652 cases)
|
14.5
|
Leisure-time activity at least 3 days/wk
vs.
3 or fewer days/month
|
0.66
(0.40-1.09)
|
0.78
(0.52-1.17)
|
0.73
(0.54-1.00)
|
Swedish Twins Cohort [20]
|
9,539
(506 cases)
|
20
|
Regular activity
vs.
very little activity
|
1.3
(0.7-2.5)
|
0.6
(0.4-1.0)
|
0.8
(0.6-1.2)
|
* Additional analyses of 97,039 postmenopausal women (2,866 cases) found that women whose daily routines included activities such as walking or heavy lifting/carrying had a lower risk of breast cancer compared to women who sat all day.
† This study found a decrease in risk of estrogen receptor-negative breast cancers among women with the highest levels of physical activity (more than 5 hours per week vs. inactive, RR was 0.53 (0.33-0.85)). There was no link between physical activity and risk of estrogen receptor-positive breast cancers.
‡ This study also found no link between physical activity at age 30 and breast cancer risk (vigorous activity vs. no activity 1.20 (0.77-1.95)), nor between physical activity at age 14 and breast cancer risk (vigorous activity vs. no activity, RR was 1.05 (0.72-1.54)).
§Among 64,777 premenopausal women in this study, average lifetime physical activity was found to decrease risk of breast cancer. Women who averaged at least 39 MET hours of activity a week during their lifetime had lower risk of breast cancer compared to inactive women, RR was 0.77 (0.64-0.93).
References
- International Agency for Research on Cancer (WHO): IARC Handbooks of Cancer Prevention, Volume 6: Weight Control and Physical Activity. IARC Press, Lyon, France, 2002.
- Peters TM, Schatzkin A, Gierach GL, et al. Physical activity and postmenopausal breast cancer risk in the NIH-AARP diet and health study. Cancer Epidemiol Biomarkers Prev. 18(1):289-96, 2009.
- George SM, Irwin ML, Matthews CE, et al. Beyond recreational physical activity: examining occupational and household activity, transportation activity, and sedentary behavior in relation to postmenopausal breast cancer risk. Am J Public Health. 100(11):2288-95, 2010.
- Eliassen AH, Hankinson SE, Rosner B, Holmes MD, Willett WC. Physical activity and risk of breast cancer among postmenopausal women. Arch Intern Med. 170(19):1758-64, 2010.
- Tehard B, Friedenreich CM, Oppert JM, Clavel-Chapelon. Effect of physical activity on women at increased risk of breast cancer: results from the E3N cohort study. Cancer Epidemiol Biomarkers Prev. 15(1):57-64, 2006.
- Lahmann PH, Friedenreich C, Schuit AJ, et al. Physical activity and breast cancer risk: the European Prospective Investigation into Cancer and Nutrition. Cancer Epidemiol Biomarkers Prev. 16(1):36-42, 2007.
- Dallal CM, Sullivan-Halley J, Ross RK, et al. Long-term recreational physical activity and risk of invasive and in situ breast cancer: the California teachers study. Arch Intern Med. 167(4):408-15, 2007.
- Bardia A, Hartmann LC, Vachon CM, et al. Recreational physical activity and risk of postmenopausal breast cancer based on hormone receptor status. Arch Intern Med. 166(22):2478-83, 2006
- Silvera SAN, Jain M, Howe GR, et al. Energy balance and breast cancer risk: a prospective cohort study. Breast Cancer Res Treat. 97(1):97-106, 2006.
- Patel AV, Calle EE, Bernstein L, Wu AH, Thun MJ. Recreational physical activity and risk of postmenopausal breast cancer in a large cohort of US women. Cancer Causes and Control. 14(6):519-29, 2003.
- Margolis KL, Mucci L, Braaten T, et al. Physical activity in different periods of life and the risk of breast cancer: the Norwegian-Swedish Women's Lifestyle and Health cohort study. Cancer Epidemiol Biomarkers Prev. 14(1):27-32, 2005.
- McTiernan A, Kooperberg C, White E, et al. Recreational physical activity and the risk of breast cancer in postmenopausal women: the Women's Health Initiative Cohort Study. JAMA. 290: 1331-6, 2003.
- Leitzmann MF, Moore SC, Peters TM, et al. Prospective study of physical activity and risk of postmenopausal breast cancer. Breast Cancer Res. 10(5):R92, 2008.
- Dirx MJ, Voorrips LE, Goldbohm RA, et al. Baseline recreational physical activity, history of sports participation, and postmenopausal breast carcinoma risk in the Netherlands Cohort Study. Cancer. 92(6):1638-1649, 2001.
- Howard RA, Leitzmann MF, Linet MS, Freedman DM. Physical activity and breast cancer risk among pre- and postmenopausal women in the U.S. Radiologic Technologists cohort. Cancer Causes Control. 20(3):323-33, 2009.
- Colditz GA, Feskanich D, Chen WY, Hunter DJ, Willett WC. Physical activity and risk of breast cancer in premenopausal women. Br J Cancer. 89(5):847-51, 2003.
- Maruti SS, Willett WC, Feskanich D, Rosner B, Colditz GA. A prospective study of age-specific physical activity and premenopausal breast cancer. J Natl Cancer Inst. 100(10):728-37, 2008.
- Chang SC, Ziegler RG, Dunn B, et al. Association of energy intake and energy balance with postmenopausal breast cancer in the prostate, lung, colorectal, and ovarian cancer screening trial. Cancer Epidemiol Biomarkers Prev. 15(2):334-41, 2006.
- Suzuki R, Iwasaki M, Kasuga Y, et al. Leisure-time physical activity and breast cancer risk by hormone receptor status: effective life periods and exercise intensity. Cancer Causes Control. 21(11):1787-98, 2010.
- Moradi T, Adami HO, Ekbom A, et al. Physical activity and risk for breast cancer a prospective cohort study among Swedish twins. Int J Cancer. 100:76-81, 2002.
Updated 07/06/11
