Home > Understanding Breast Cancer > Breast Cancer Research > Table 1: Body weight and breast cancer risk

  


Table 1: Body weight and breast cancer risk

  

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.

Introduction: Body weight affects the risk of premenopausal and postmenopausal breast cancer differently. In premenopausal women, being overweight modestly decreases the risk of breast cancer. In postmenopausal women, however, being obese or overweight increases the risk of breast cancer.

Postmenopausal hormone use, body weight and breast cancer

Postmenopausal hormone use may mask the true effect weight has on breast cancer risk. Thus, the increase in risk from being obese or overweight seen in postmenopausal hormone users is lower than that seen in non-users. This does not mean postmenopausal hormones protect against breast cancer. Rather, the increased risk of breast cancer from postmenopausal hormones is likely masking the increase in risk from body weight. For this reason, many studies report findings by hormone use.

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 1,000 breast cancer cases, pooled analyses and meta-analyses. 

Table notes: In the studies below, researchers use a measure called body mass index (BMI) to estimate body fat. BMI takes into account height and weight. Calculate your BMI. 

Relative risk above 1 indicates increased risk. Relative risk below 1 indicates decreased risk. 
  

Study 

Study Population
(number of participants) 

Follow-up
(years) 

Levels of
Body Mass Index (BMI) Compared 

Relative Risk of Breast Cancer in Heavier Women Compared to Leaner Women, by Menopausal Status
RR (95% CI) 

Premenopausal 

Postmenopausal 

Prospective cohort studies 

Tretli et al. [1]

567,333
(8,427 cases)

18

Very small differences in BMI

0.84 (0.74-0.95)

1.16 (1.09-1.23)

Million Women Study (UK) [2]

1,222,630
(6,808 cases)

5.4

30 or more 
vs.
Less than 22.5

0.79 (0.68-0.92)

1.29 (1.22-1.36)

Korean Cancer Prevention Study [3]

443,273
(3,973 cases)

10.8

25-29.9
vs.
23-24.9

  

1.18 (1.04-1.34)*
     

30 or more
vs.
23-24.9

  

1.13 (0.84-1.53)*

Nurses Health Study [4]

95,256
(2,517 cases)

16

More than 31 vs.
20 or less

0.62 (0.45-0.86)

1.59 (1.09-2.32)† 

NIH-AARP Diet and Health Study [5]

  99,039
(2,111 cases)

3.9

30-39.9
vs.
18.5-22.4

  

1.89 (1.40-2.55)‡ 

PLCO Cancer Screening Trial [6]

70,575
(2,063 cases)

5

25-29
vs.
18.5-24.9

  

1.06 (0.95-1.17)
     

 30-34.9
vs.
18.5-24.9

  

1.10 (0.97-1.26)
     

35 or more 
vs.
18.5-24.9

  

1.21 (1.02-1.43)

EPIC Study [7]

176,886
(1,879 cases)

4.7

25-29.9
vs.
Less than 25

0.88 (0.70-1.10)

1.30 (1.12-1.51)§ 

 
 
 

30 or more 
vs.
Less than 25

0.89 (0.64-1.22)

1.31 (1.08-1.59)§ 

Cancer Prevention Study-II (CPS-II) [8]

65,756
(1,934 cases)

7-9

35 or more 
vs.
Less than 22

  

1.61 (1.22-2.12)† 

National Breast Screening Study-Canada [9]

40,318
(1,673 cases)

16.4

30 or more
vs.
Less than 25

1.01 (0.74-1.37)

1.26 (0.95-1.67)

Lundqvist et al. [10]

36,490
(1,637 cases)

26.3

30 or more 
vs.
18.5-25

0.8 (0.4-1.3)*

1.3 (1.0-1.7)

E3N Women’s Cohort Study—France [11]

94,805
(1,522 cases)

9.7

30 or more 
vs.
18.5-25

0.66 (0.40-1.10)

1.17 (0.89-1.57)† 

Tornberg et al. [12]

47,003
(1,466 cases)

25

28 or more 
vs.
Less than 22

0.41Sig 

1.13Sig 

Nurses' Health Study II [13]

113,130
(1,398 cases)

14

30 or more 
vs.
Less than 20

0.81 (0.68-0.96)
 

Swedish Mammography Screening Cohort [14]

51,823
(1,188 cases)

8.3

30 or more 
vs.
18.5-24.9

  

1.28 (1.07-1.52)|| 

Black Women's Health Study [15]

52,080
(1,062 cases)

10

35 or more 
vs.
Less than 25

 1.35 (0.53-3.47)

0.78 (0.58-1.05)

Vorarlberg Health Monitoring and Promotion Program-Austria [16]

78,484
(1,045 cases)

9.9

35 or more 
vs.
18.5-24.9

  

1.01 (0.72-1.42) 

Women’s Health Initiative [17]

85,917
(1,030 cases)

2.9

More than 31.1 
vs.
22.6 or less

  

2.52 (1.62-3.93)†  

Pooled and meta-analyses 

van den Brandt et al. [18]

337,819
(4,385 cases)
 

30 or more 
vs.
Less than 21

0.58 (0.34-1.00)

1.27 (1.03-1.55)

Suzuki et al. [19]

4 studies

  

Highest BMI vs.
Average BMI

  

For ER+/PR+ tumors:
1.74 (1.34-2.25)

For ER-/PR- tumors:
0.90 (0.53-1.52)

 Sig = Results were statistically significant.

* Includes pre- and postmenopausal women.

† Relative risk is for postmenopausal women who never used postmenopausal hormones. Relative risk among postmenopausal hormone users was also statistically non-significant.

‡ Results are for postmenopausal women who never used postmenopausal hormones. Among postmenopausal hormone users, there was no increase in risk, 1.13 (0.80-1.61).

§ Relative risks are for postmenopausal women who never used postmenopausal hormones. For postmenopausal hormone users, relative risks were 0.94 (0.76-1.15) for women with BMI 25.0-29.9 vs. <25.0 and 0.66 (0.45-0.98) for those with BMI >=30.0 vs. <25.0.

|| Results showed that among postmenopausal women who never used postmenopausal hormones, risk of breast cancer was 1.38 (1.07-1.77) and among postmenopausal hormone users, risk of breast cancer was 1.04 (0.75-1.45).

¶ Combined premenopausal and postmenopausal breast cancer risk. For women aged 65 and older, BMI 30-34.9 vs. 18.5-24.9 showed a positive association with breast cancer risk 1.48 (1.12-1.95).

References  

  1. Tretli S. Height and weight in relation to breast cancer morbidity and mortality. A prospective study of 570,000 women in Norway. Int J Cancer. 44:23-30, 1989.
  2. Reeves GK, Pirie K, Beral V, Green J, Spencer E, Bull D. Cancer incidence and mortality in relation to body mass index in the Million Women Study: cohort study. BMJ. 335(7630):1134, 2007.
  3. Jee SH, Yun JE, Park EJ, et al. Body mass index and cancer risk in Korean men and women. Int J Cancer. 123(8):1892-6, 2008.
  4. Huang Z, Hankinson SE, Colditz GA, et al. Dual effects of weight and weight gain on breast cancer risk. JAMA. 278(17):1407-1411, 1997.
  5. Ahn J, Schatzkin A, Lacey JV Jr, et al. Adiposity, adult weight change, and postmenopausal breast cancer risk. Arch Intern Med. 167(19):2091-102, 2007.
  6. Lacey JV Jr, Kreimer AR, Buys SS, et al. for the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial Project Team. Breast cancer epidemiology according to recognized breast cancer risk factors in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial Cohort. BMC Cancer. 9:84, 2009.
  7. Lahmann PH, Lissner L, Gullberg B, Olsson H, Berglund G. A prospective study of adiposity and postmenopausal breast cancer risk: the Malmo Diet and Cancer Study. Int J Cancer. 103(2):246-52, 2003.
  8. Feigelson HS, Jonas CR, Teras LR, Thun MJ, Calle EE. Weight gain, body mass index, hormone replacement therapy, and postmenopausal breast cancer in a large prospective study. Cancer Epidemiol Biomarkers Prev. 13(2):220-4, 2004.
  9. 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.
  10. Lundqvist E, Kaprio J, Verkasalo PK, et al. Co-twin control and cohort analyses of body mass index and height in relation to breast, prostate, ovarian, corpus uteri, colon and rectal cancer among Swedish and Finnish twins. Int J Cancer. 121(4):810-8, 2007.
  11. Tehard B, Lahmann PH, Riboli E, Clavel-Chapelon F. Anthropometry, breast cancer and menopausal status: Use of repeated measurements over 10 years of follow-up-results of the French E3N women's cohort study. Int J Cancer. 111(2):264-9, 2004.
  12. Tornberg SA and Carstensen JM. Relationship between Quetelet’s Index and cancer of breast and female genital tract in 47,000 women followed for 25 years. Br J Cancer. 69:358-361, 1994.
  13. Michels K, Terry KL, Willett WC. Longitudinal study on the role of body size in premenopausal breast cancer. Arch Intern Med.166(21):2395-402, 2006.
  14. Suzuki R, Rylander-Rudqvist T, Ye W, et al. Body weight and postmenopausal breast cancer risk defined by estrogen and progesterone receptor status among Swedish women: A prospective cohort study. Int J Cancer. 119(7):1683-9, 2006.
  15. Palmer JR, Adams-Campbell LL, Boggs DA, Wise LA, Rosenberg L. A prospective study of body size and breast cancer in black women. Cancer Epidemiol Biomarkers Prev. 16(9):1795-802, 2007.
  16. Rapp K, Schroeder J, Klenk J, et al. Obesity and incidence of cancer: a large cohort study of over 145,000 adults in Austria. Br J Cancer. 93(9):1062-7, 2005.
  17. Morimoto LM, White E, Chen Z, Chlebowski RT, Hays J, Kuller L, Lopez AM, Manson J, Margolis KL, Muti PC, Stefanick ML, McTiernan A. Obesity, body size, and risk of postmenopausal breast cancer: the Women's Health Initiative (United States). Cancer Causes Control. 13(8):741-51, 2002.
  18. van den Brandt PA, Spiegelman D, Yaun S, et al. Pooled analysis of prospective cohort on height, weight, and breast cancer risk. Am J Epidemiol. 152(6):514-527, 2000.
  19. Suzuki R, Orsini N, Saji S, Key TJ, Wolk A. Body weight and incidence of breast cancer defined by estrogen and progesterone receptor status--a meta-analysis. Int J Cancer. 124(3):698-712, 2009. 

 Updated 07/06/11