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Home > Understanding Breast Cancer > Breast Cancer Research > Table 1: Body Weight and Breast Cancer Risk

  


Table 1: Body Weight and Breast Cancer Risk

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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: The effect that weight has on the risk of breast cancer depends on whether women are premenopausal or postmenopausal. In premenopausal women, being overweight offers modest protection against breast cancer. In postmenopausal women, however, being obese or overweight increases the risk of breast cancer.

Because the use of postmenopausal hormones may mask the true effect that weight has on breast cancer risk, many studies report findings by use of hormones. Overall, 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 that postmenopausal hormones protect against breast cancer. Rather, it is thought that the increased risk of breast cancer from postmenopausal hormones masks the true impact of body weight on breast cancer risk.

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 300 breast cancer cases and pooled analyses.

Table notes: In the studies below, researchers use a measure called body mass index (BMI) to estimate body fat. BMI takes into account a person’s 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 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 vs. <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

25.0-29.9 vs. 23.0-22.9

  

1.18 (1.04-1.34)*
     

>=30 vs. 23.0-22.9

 

1.13 (0.84-1.53)*
Nurses Health Study [4]

95,256

(2,517 cases)

 16  

>31 vs. <=20

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

30.0 to 39.9 vs. 18.5 to 22.4

 		  

1.89 (1.40-2.55)‡

 

EPIC study [6]

176,886

(1,879 cases)

4.7

25.0-29.9 vs. <25.0

0.88 (0.70-1.10)

1.30 (1.12-1.51)§



>=30.0 vs. <25.0

0.89 (0.64-1.22)

1.31 (1.08-1.59)§
CPS-II [7]

65,756

(1,934 cases)

 7-9

>=35 vs. <22.0

  

1.61 (1.22-2.12)†

National Breast Screening Study-Canada [8]

40,318

(1,673 cases)

 16.4

>=30 vs. <25

1.01 (0.74-1.37)

  

1.26 (0.95-1.67)

Lundqvist et al. [9]

36,490

(1,637 cases)

 26.3

>=30.0 vs. 18.5-25

0.8 (0.4-1.3)*

1.3 (1.0-1.7)

E3N Women’s Cohort Study—France [10]

94,805

(1,522 cases)

 9.7

>=30.0 vs. 18.5-25

 

0.66 (0.40-1.10)

 		 1.17 (0.89-1.57)†

Tornberg et al. [11]

47,003

(1,466 cases)

 25

>=28 vs. <22

 0.41Sig 1.13Sig

Nurses' Health Study II [12]

113,130

(1,398 cases)

14

>=30.0 vs. <20.0

0.81 (0.68-0.96)

Swedish Mammography Screening Cohort [13]

51,823

(1,188 cases)

 8.3

>=30 vs. 18.5-24.9

  

1.28 (1.07-1.52)||

Black Women's Health Study [14]

52,080

(1,062 cases)

 10

>=35 vs. <25

  1.35 (0.53-3.47) 0.78 (0.58-1.05)

Vorarlberg Health Monitoring and Promotion Program-Austria [15]

78,484

(1,045 cases)

 9.9

>=35 vs. 18.5-24.9

   1.01 (0.72-1.42)

Women’s Health Initiative [16]

85,917

(1,030 cases)

 2.9

>31.1 vs. <=22.6

   2.52 (1.62-3.93)†

PLCO Cancer Screening Trial [17]

27,541

(764 cases)

 9.3**  

27.5-29.9 vs. <=22.4

  

1.42 (1.11-1.83)

 
       

>=30.0 vs. <=22.4

    

1.35 (1.06-1.70)

Norway and Sweden cohort [18]

99,717

(733 cases)

7-8

>=30.0 vs. <20

0.62 (0.40-0.97)

Danish Diet, Cancer, and Health Study [19]

23,788

(633 cases)

 6.7  

>=30 vs. 18.5 to <25

   1.17 (0.79-1.73)††  
Song et al. [20]

170,481(612 cases)

 8.8

>=30 vs. 21.0 to 22.9

  

1.86 (1.25-2.76)

Northern Sweden Health and Disease Cohort [21]

35,362

(514 cases)

 8.2

>26.0 vs. 18.5-21.5

0.58 (0.29-1.11) 

  

Japan Public Health Center-based Prospective Study [22]

55,537

(441 cases)

9.9

>=30 vs. <19

1.35 (0.53-3.47)

2.28 (0.94-5.53)‡‡

Iowa Women's Health Study [23]

36,658

(428 cases)

16

>29.5 vs. <23.5

Age 55-64 years:
1.34 (1.03-1.75)

Age 65-74 years:
1.48 (1.26-1.73)

Age 75-84 years:
1.44 (1.12-1.84)

Krebs et al. [24]

7,523

(350 cases)

11.3

>=30.0 vs. <25.0

1.55 (1.13-2.13)

Pooled analyses

Van den Brandt et al. [25]

337,819

(4,385 cases)

>=30 vs. <21

0.58 (0.34-1.00)

1.27 (1.03-1.55)

Sig=Results were statistically significant.

* Includes pre- and postmenopausal women.

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

‡ Results are for women who never used hormone replacement therapy. 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 hormone replacement therapy. 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 women who never used hormone replacement therapy, 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).

** Median follow-up 4.9 years. 

†† Results are for women who never used hormone replacement therapy. Among postmenopausal hormone users, there was also no increase in risk, 0.94 (0.67-1.31).

‡‡Results showed that increasing BMI increased risk of estrogen receptor-positive breast cancer among postmenopausal women with a hazard ratio of 1.08 (1.01-1.15).

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. 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. 
  7. 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. 
  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. 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. 
  10. 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. 
  11. 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. 
  12. 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.
  13. 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. 
  14. 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. 
  15. 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. 
  16. 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. 
  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. Weiderpass E, Braaten T, Magnusson C, et al. A prospective study of body size in different periods of life and risk of premenopausal breast cancer. Cancer Epidemiol Biomarkers Prev. 13(7):1121-7, 2004. 
  19. Mellemkjaer L, Bigaard J, Tjønneland A, et al. Body composition and breast cancer in postmenopausal women: a Danish prospective cohort study. Obesity (Silver Spring). 14(10):1854-62, 2006. 
  20. Song YM, Sung J, Ha M. Obesity and risk of cancer in postmenopausal Korean women. J Clin Oncol. 26(20):3395-402, 2008. 
  21. Lukanova A, Bjor O, Kaaks R, et al. Body mass index and cancer: results from the Northern Sweden Health and Disease Cohort. Int J Cancer. 118(2):458-66, 2006. 
  22. Iwasaki M, Otani T, Inoue M, Sasazuki S, Tsugane S for the Japan Public Health Center-based Prospective Study Group. Body size and risk for breast cancer in relation to estrogen and progesterone receptor status in Japan. Ann Epidemiol. 17(4):304-12, 2007. 
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  25. 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.

Updated 08/27/09