| This summary table contains detailed information about research studies. While viewing summary tables offers an informative glimpse at the science behind many breast cancer guidelines and recommendations, they should be viewed with some caution. There are a number of concepts you must understand to be able to successfully read and interpret research tables. To get some background information about understanding research tables, please see How to Read a Research Table. |
Introduction: Many studies have looked at the relationship between physical activity and 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, cohort studies have had more inconsistent results (see table below). When the evidence is looked at as a whole, it appears that regular physical activity moderately protects against breast cancer. This is seen most clearly in postmenopausal women [1].
Find more information on 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 200 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]
|
182,862
(6,609 cases)
|
7 |
At least 20 min activity at least 5 times/wk vs. inactive
|
|
0.92
(0.85-1.00)
|
|
French E3N cohort [3]
|
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 MET hrs/wk recreational activity
vs.
inactive |
|
|
0.81
(0.72-0.92)
|
| EPIC [4] |
218,169
(3,423 cases) |
6.4 |
>42 MET hrs/wk
vs.
<14 MET hrs/wk of recreational activity |
0.94
(0.76-1.15)
|
0.96
(0.85-1.08)
|
|
Nurses’ Health Study [5]
|
121,701
(3,137 cases) |
16 |
At least 7 hrs/day moderate to vigorous activity
vs.
<1 hr/wk |
Significantly lower (similar to pre/post combined)
|
Significantly lower (similar to pre/post combined)
|
0.82
(0.70-0.97)
|
California Teachers Study [6]
|
110,599
(2,649 cases) |
6.6 |
>5 hrs/wk moderate physical activity
vs.
inactive |
|
|
1.03
(0.88-1.19)* |
Iowa Women’s Health Study [7]
|
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 [8]
|
40,318
(2,545 cases) |
16.4 |
> 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)
|
CPS II [9]
|
72,608
(1,520 cases)
|
5
|
>42 MET hrs/wk
vs.
>0 to 7.0 MET hrs/wk |
|
0.71
(0.49-1.02)
|
|
Norwegian-Swedish Women’s Lifestyle and Health Cohort Study [10]
|
99,504
(1,166 cases)
|
9.1 |
Vigorous activity vs. no activity
|
1.24
(0.85-1.82)‡
|
|
|
Women’s Health Initiative [11]
|
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 [12]
|
32,269
(1,506 cases)
|
8.4 |
395-721 MET hrs/wk vs. 105-244 MET hrs/wk
|
|
0.87
(0.74-1.02)
|
|
Netherlands Cohort Study [13]
|
62,537
(1,208 cases)
|
7.3 |
More than 90 minutes/day of activity
vs.
<30 minutes/day |
|
0.76
(0.58-0.99)
|
|
U.S. Radiologic Technologies cohort [14]
|
45,631
(864 cases)
|
8.9 |
At least 97 MET hrs/wk vs. <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 [15,16]
|
110,468
(849 cases)
|
10 |
>=27 MET hrs/wk
vs.
<3 MET hrs/wk |
1.04
(0.82-1.33)†
|
|
|
PLCO Cancer Screening Trial [17]
|
27,541
(764 cases)
|
4.9 |
3 hrs/wk recreational activity
vs.
inactive |
|
1.02
(0.79-1.30)
|
|
| |
|
|
>=4 hrs/wk recreational activity
vs.
inactive |
|
0.78
(0.61-0.99)
|
|
| Swedish Twins Cohort [18] |
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)
|
Rintala et al.-Finland [19]
|
10,049
(465 cases)
|
20.9 |
Physical education teachers
vs.
language teachers |
0.79
(0.46-1.36)
|
0.86
(0.62-1.18)
|
|
National Health Screening Survey (NHSS) Norway [20]
|
25,624
(351 cases)
|
14 |
Regularly active
vs.
sedentary
|
0.53
(0.25-1.14)
|
0.67
(0.41-1.10)
|
|
| Mertens et al. [21] |
7,994
(342 cases)
|
13.1 |
Most active leisure activity
vs.
least active |
|
|
1.00
(0.64-1.54)
|
| |
|
|
Most active sports activity vs.
least active |
|
|
1.31
(0.87-1.96)
|
| Luoto et al. [22] |
30,548
(332 cases)
|
15 |
Daily activity
vs.
less than once per week |
1.25
(0.7-1.22) |
0.97
(0.65-1.44)
|
1.01
(0.72-1.42)
|
Adventist Health Study, United States [23]
|
20,341
(218 cases)
|
6 |
Frequent activity
vs.
infrequent activity |
|
|
1.5
(1.1-1.9)
|
Japan Collaborative Cohort Study [24]
|
30,157
(207 cases)
|
12.4 |
Most active vs. other women in study
|
0.13
(0.02-0.91)
|
0.53
(0.29-0.96)
|
|
| |
|
|
Walking at least 1 hr/day vs. <30 min/day
|
|
|
0.73
(0.53-1.01)
|
* The study found a decrease in risk of estrogen receptor-negative breast cancers among women with the highest levels of physical activity (>5 hrs/wk vs. inactive 0.53 (0.33-0.85)). There was no association between physical activity and risk of estrogen receptor-positive breast cancers.
† Among 64,777 premenopausal women in this study, average lifetime physical activity was found to decrease risk of breast cancer. Women with at least 39 MET hours of activity a week on average during their lifetime had lower risk of breast cancer compared to inactive women, RR of 0.77 (0.64-0.93).
‡ This study also found no association 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 1.05 (0.72-1.54)).
References
1. International Agency for Research on Cancer (WHO): IARC Handbooks of Cancer Prevention, Volume 6: Weight Control and Physical Activity. IARC Press, Lyon, France, 2002.
2. 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.
3. 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.
4. 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.
5. Rockhill B, Willett WC, Hunter DJ, et al. A prospective study of recreational physical activity and breast cancer risk. Arch Intern Med. 159(19):2290-2296, 1999.
6. 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.
7. 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
8. 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.
9. 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.
10. 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.
11. 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.
12. 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.
13. 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.
14. 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.
15. 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.
16. 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.
17. 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.
18. 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.
19. Rintala P, Pukkala E, Laara E, Vihko V. Physical activity and breast cancer risk among female physical education and language teachers: a 34-year follow-up. Int J Cancer. 107(2):268-70, 2003.
20. Thune I, Brenn T, Lund E, Gaard M. Physical activity and the risk of breast cancer. N Engl J Med. 336(18):1269-1275, 1997.
21. Mertens AJ, Sweeney C, Shahar E, et al. Physical activity and breast cancer incidence in middle-aged women: a prospective cohort study. Breast Cancer Res Treat. 97(2):209-14, 2006.
22. Luoto R, Latikka P, Pukkala E, et al. The effect of physical activity on breast cancer risk: a cohort study of 30,548 women. Eur J Epidemiol. 16(10):973-980. 2000.
23. Fraser GE and Shavlik D. Risk factors, lifetime risk, and age at onset of breast cancer. Annals of Epidemiology. 7(6):375-382, 1997.
24. Suzuki S, Kojima M, Tokudome S, et al. for the Japan Collaborative Cohort Study Group. Effect of physical activity on breast cancer risk: findings of the Japan collaborative cohort study. Cancer Epidemiol Biomarkers Prev. 17(12):3396-401, 2008.
Updated 09/04/09
