Table 2: Selected characteristics of studies in postmenopausal women included in the paper.

First author, year, and countryStudy design PopulationCases/controls or P-yearsType of exposureRange of exposureRR (95% CI)Variables of adjustment or comment

Lahmann 2004
Germany [23]
BMI Study center, age, educational attainment,
smoking status, alcohol consumption,
parity, age at first pregnancy, age at
menarche, and current pill use
 non-HRT>30 versus <251.31 (1.08–1.59)
CohortCaucasian1,405/103,344 HRT>30 versus <250.66 (0.45–0.98)
 non-HRT>0.84 versus <0.730.94 (0.74–1.21)
 HRT>0.84 versus <0.730.85 (0.60–1.20)
Tehard 2006
France [28]
Cohort Caucasian860/41497BMI
≥30 versus <18.5
≥0.82 versus 0.74
1.44 (1.04–1.99)   
1.03 (0.83–1.28)
FHBC, age at menarche, age at first birth, parity, history of benign breast disease, alcohol consumption, number of years of education, marital status, and physical activity
Bardia 2008
United States [44]
CohortCaucasian2503/35941Weight at age 12Above versus average0.85 (0.74–0.98)Age, education status, age at menopause, age at menarche, parity, age at first birth, BMI at age 18 years, OC, HRT, smoking, alcohol, and physical activity level
Baer 2010
United States [45]
CohortCaucasian4974/188,860Body fatness
 Childhood 5–10 Y
 Adolescent 10–20 Y
0.1 unit increase
0.1 unit increase
0.93 (0.90–0.95)
0.91 (0.89–0.93)
Age, time period, parity/age at first birth, FHBC, personal history of benign BC, height, alcohol intake, OC use, birth weight, age at menopause, and HRT use
Kuriyama 2005
Japan [46]
Cohort Asian65/9,666 BMI≥30 versus <25 2.67 (1.03–6.92)Age, smoking, alcohol, consumption of meat, fish, fruits, green or yellow consumption of bean-paste soup, type of health, parity, age at menarche, and age at FFT pregnancy
Iwasaki 2007   
Japan [47]
CohortAsian441/55,537BMI>30 versus <19 2.28 (0.94–5.53)Age, area, number of births, age at first birth, and height
Kawai 2010   
Japan [22]
CohortAsian108/10,106BMI≥25 versus <202.54 (1.16–5.55)Age, education, smoking, alcohol, and time spent walking, Menstrual and reproductive factors, HRT, and FHBC
Palmer 2007
United States [35]
CohortAfrican-American455/59,000 BMI at age 18
Current BMI
≥25 versus <20
≥37 versus <25
≥0.87 versus <0.71
0.55 (0.37–0.82)   
0.78 (0.58–1.05)   
1.01 (0.74–1.40)
Age, age at menarche, parity, age at first birth, and family history of breast cancer
Canada [48]
Case-controlCaucasian771/762 BMI
≥31.3 versus <24.1
≥0.83 versus <0.75
0.99 (0.74–1.32)   
1.43 (1.07–1.93)
Age, total caloric intake, physical activity, educational level, HRT, diagnosed with benign BC, FHBC, alcohol, and current smoke
Huang 1999  
United States [38]
436/354WHR >0.8 versus ≤0.81.40 (1.10–1.70)Age at menarche, nulliparity, breastfeeding, Abortion or miscarriage, BMI, WHR, oral contraceptive, HRT, FHBC, smoking, alcohol, education, medical radiation to the chest
 Black30.1–59.2 versus 14.6–24.60.68 (0.33–1.42)
Hall 2000
United States [40]
382/419 White30.1–59.2 versus 14.6–24.61.08 (0.58–2.00)Age, age at menarche, parity/age at FFT pregnancy, lactation, and education
 Black0.86–1.34 versus 0.6–0.771.62 (0.70–3.79)
 White0.86–1.34 versus 0.6–0.771.64 (0.88–3.07)
BMI at 18 years ≥25 versus <20 0.72 (0.55–0.96)
Berstad 2010
United States [30]
1,900/2,006Recent BMIAge, race, education, study site, FHBC, parity, age at menopause, and HRT
 Caucasian≥35 versus <250.75 (0.53–1.06)
 African-American≥35 versus <251.26 (0.55–1.85)
Ogundiran 2010
Nigeria [34]
Case-controlAfrican498/266BMI≥28 versus <210.76 (0.48–1.21)Age, ethnicity, education, menarche, parity, age at FFTP, breastfeeding, menopausal status, age at menopause, FHBC, benign breast disease, contraceptive, alcohol
Adebamowo 2003
Nigeria [49]
Case-controlAfrican234/273 BMI≥30 versus <201.82 (0.78–4.31)Age, age at menarche, age at FFT pregnancy, height
Wenten 2002
United States [50]
687/820BMI Age; FHBC; total MET-hours; parity; OC; breastfeeding; age at first live birth; months of HRT use
 Caucasian≥30 versus <222.77 (0.86–8.89)
 Hispanic≥30 versus <221.32 (0.47–3.72)
BMI non-HRT userAge, center, physical activity level, energy intake, alcohol intake, age at menopause, parity, and Height
 Caucasian>30 versus <251.61 (1.05–2.45)
Slattery 2007
United States [36]
2,325/2,525 Hispanic >30 versus <250.80 (0.44–1.45)
WHR non-HRT user
 Caucasian>0.9 versus <0.81.51 (0.93–2.46)
 Hispanic>0.9 versus <0.80.77 (0.39–1.50)
Ng 1997
Singapore [33]
Case-control Asian130/585WHR>0.86 versus <0.758.19 (3.40–19.50)Age, menopausal status, age at menarche, parity, number of birth, age at FFT birth, HRT, OC, breast feeding, smoking, height, weight, and BMI
Chow 2005
China [20]
Case-controlAsian198/353BMI23–27 versus <19
<31 versus <19
1.73 (1.04–2.86)   
3.82 (1.03–14.27)
Age, number of pregnancies, family history of breast cancer, income, smoking, alcohol, use of OC, and education
Wu 2007   
Japan [39]
>24.60 versus ≤20.43
>0.84 versus ≤0.76
1.35 (0.95–1.93)   
1.48 (1.02–2.15)
Age, Asian ethnicity, duration of residence in the US, education, menarche, parity, menopausal status, age at menopause, intake of tea and soy, and physical activity
Mathew 2008
India [24]
Case-controlAsian968/691BMI25–29.9 versus <25
>30 versus <25
1.29 (1.00–1.66)   
1.00 (0.64–1.54)
Age, center, religion, marital status, education socioeconomic status, residence status, parity, age at 1st childbirth, duration of breast feeding, and physical activity
Connolly 2002
Canada [37]
Meta-analysisAll19 studiesWHR0.1 unit increase1.50 (1.10–2.04) A meta-analysis was done to summarize the literature on WHR and breast cancer risk published from January 1966 to August 2002
Harvie 2003
United kingdom [32]
Meta-analysisAll8 studies:
5 cohort and
3 case-control
WHR Lifestyles and reproductive factors (confounders that were found to be significant in proportional hazard regression analysis) 
 Cohort studies0.75 versus 0.801.32 (1.16–1.49)
 Case-control  studies0.75 versus 0.801.82 (0.85–3.85)
Suzuki 2009 Sweden [27]Meta-analysis All31 studies:
9 cohort and
22 case-control
BMI ER+PR+0.5 unit increase1.33 (120–1.48)Meta-analysis of cohort and case-control studies (from 1970 to 2007) was performed to clarify the association between body weight and the incidence of BC defined by ER/PR status of the tumors
Van Den Brandt 2000
United States [29]
Meta-analysisCaucasian4,385/337,819BMI21 versus 311.26 (1.09–1.46)HRT, OC, history of benign breast disease, FHBC, smoking status, education, fat intake, fiber intake, energy intake, and alcohol intake
Renehan 2008
United States
31 studiesBMI all
 North American
 European and Australian
5 units increase
5 units increase
5 units increase
5 units increase
1.12 (1.08–1.16)   
1.15 (1.08–1.23)   
1.09 (1.04–1.48)   
1.31 (1.15–1.48)
Cohort and case-control studies published from 1966 to November 2007 were included in the analysis. The dose response meta-analysis was adjusted by geographic region and cancer site
Sarkissyan 2011
United States [51]
237/234BMI Age, ethnicity, comorbidity, and menopausal status
 African-American≥30 versus <254.8 (1.8–12.7)
 Hispanic≥30 versus <251.4 (0.5–4.1)

BMI: measurement of body mass index (in kg/m2); WHR: waist-hip ratio; ER: estrogen receptor; PR: progesterone receptor; BC: breast cancer; HRT: hormonal replacement therapy; OC: oral contraceptives; FFT: age at first full-term pregnancy; FHBC: family history of breast cancer; Y: years.
Bold: statistically significant.