Table 2 Studies assessing the association of birth weight and the risk for breast cancer

Case-control studies

[42]

1988

PCC

153

461

USA

1,162–2,948

Referent

Matched analysis; P for trend = 0.41

2,949–3,340

0.65 (0.33–1.26)

3,341–4,451

0.76 (0.41–1.43)

[12]^a

1992

LCC

458

1,197

Sweden

<2,500

1.18 (0.60–2.33)

Adjusted for age and birth date

2,500–2,999

Referent

3,000–3,499

1.29 (0.90–1.91)

3,500–3,999

1.47 (1.00–2.18)

≥ 4,000

1.23 (0.80–2.00)

[13]

1996

NCC

550

1,478

USA

<2,500

0.56 (0.34–0.93)

Adjusted for age

2,500–2,999

0.68 (0.47–0.99)

3,000–3,499

0.71 (0.50–0.99)

3,500–3,999

0.85 (0.59–1.22)

≥ 4,000

Referent

[14]

1996

PCC

922

1,194

USA

Age 21–45 years:

Adjusted for age, menopausal status, and maternal smoking; P for trend = 0.06 among both groups. The OR (95% CI) for birth weight ≥ 4,000 g among patients with early-onset breast cancer (≤ 30 years old) was 3.3 (1.0–11.0)

   <2,500

1.3 (0.9–2.0)

   2,500–2,999

Referent

   3,000–3,499

1.3 (1.0–1.7)

   3,500–3,999

1.2 (0.8–1.6)

   ≥ 4,000

1.7 (1.1–2.5)

Age 50–64 years:

<2,500

0.9 (0.5–1.7)

2,500–2,999

Referent

3,000–3,499

1.1 (0.7–1.7)

3,500–3,999

0.8 (0.4–1.3)

≥ 4,000

0.6 (0.3–1.1)

[32]

1997

NCC

1068

2,027

Sweden

<2,500

0.80 (0.50–1.26)

Adjusted for maternal age, socioeconomic status, parity, and pre-eclampsia or eclampsia, neonatal jaundice, severe prematurity, and twinship

2,500–2,999

Referent

3,000–3,499

1.00 (0.79–1.28)

3,500–3,999

0.99 (0.77–1.26)

≥ 4,000

1.04 (0.77–1.41)

[33]

1998

PCC

510

436

USA

<2,500

1.2 (0.7–2.1)

Crude ORs

2,500–2,999

Referent

3,000–3,499

1.0 (0.7–1.5)

3,500–3,999

1.0 (0.7–1.5)

≥ 4,000

1.3 (0.7–2.3)

[15]

2000

LCC

484

2,870

USA

<1,500

1.59 (0.61–4.11)

Crude ORs

1,500–2,499

1.33 (0.94–1.90)

2,500–3,499

Referent

3,500–4,499

1.08 (0.87–1.34)

≥ 4,500

3.29 (1.37–7.92)

[34]

2001

LTCC

87

87

Sweden

<1,999

Referent

Matched analysis by conditional logistic regression

2,000–2,499

1.6 (0.6–4.0)

2,599–2,999

2.4 (0.9–6.2)

≥ 3,000

1.6 (0.4–5.6)

(P trend = 0.05)

[43]

2001

LCC

319

768

USA

<2,500

1.4 (0.55–3.4)

Crude ORs. Higher birth weight (≥ 3,500 g) carried a marginal significantly higher risk for breast cancer (OR 1.76 [95% CI 0.90–3.35]) relative to lower birth weight (<3,500 g)

2,500–3,750

Referent

≥ 3,750

0.9 (0.50–1.6)

[16]

2001

LTCC

90

90

Sweden

≤ 2,000

Referent

Crude ORs. Study subjects were women with opposite-sexed pair twins

2,001–2,500

3.2 (0.8–12.6)

2,501–3,000

3.5 (1–13)

3,001–3,500

5.8 (1.3–25.7)

≥ 3,501

12.1 (1.1–138.8)

[35]

2002

PCC

2,088

2,187

USA

<2,500

1.10 (0.90–1.35)

Adjusted for age and residential regions (states)

2,500–2,999

0.90 (0.70–1.10)

3,000–3,499

Referent

3,500–3,999

1.07 (0.90–1.30)

4,000–4,499

0.89 (0.70–1.14)

≥ 4,500

1.18 (0.90–1.51)

[44]

2002

PCC

288

350

China

<2,500

0.9 (0.4–2.0)

Adjusted for age income, family history of breast cancer in first-degree relative, history of fibroadenoma, age at menarche, parity, and age at first live birth.

2,500–2,999

Referent

3,000–3,499

1.1 (0.8–1.6)

3,500–3,999

0.8 (0.4–1.4)

≥ 4,000

0.7 (0.4–1.4)

[17]

2002

LCC

373

1,150

USA

<3,090

Referent

Adjusted for parity and age at first birth. P for trend = 0.02

3,090–3,410

1.1 (0.8–1.5)

3,420–3,720

1.2 (0.9–1.6)

≥ 3,630

1.4 (1.1–1.9)

[18]

2003

LCC

881

3,423

Denmark

<2,500

1.66 (1.00–2.51)

Adjusted for mother's marital status, maternal age, and birth order

2,500–2,999

0.83 (0.60–1.10)

3,000–3,499

Referent

3,500–3,999

0.98 (0.80–1.17)

≥ 4,000

1.25 (1.00–1.55)

[19]

2004

NCC

89

238

Sweden

100 g increase

1.06 (1.00–1.12)

Adjusted for gestational age, birth year, and maternal hypertension/proteinuria

[45]

2004

LCC

2471

9801

USA

<1,500

0.64 (0.40–1.11)

Adjusted for age and maternal age at first birth

1,500–1,999

1.05 (0.70–1.68)

2,000–2,499

1.02 (0.80–1.31)

2,500–3,499

Referent

3,500–3,999

0.97 (0.90–1.08)

4,000–4,499

0.93 (0.80–1.11)

≥ 4,500

0.69 (0.40–1.09)

[36]

2004

PCC

196

167

USA

All subjects:

Adjusted for age, race and sampling fractions, body mass index, household income, and maternal age. Tertiles are race specific with cutpoints derived from controls. White women: <3,062, 3,062–3,458, >3,458 g; black women: <3,146, 3,146–3,488, >3,488 g. Restricted data using birth weight measured in pounds and ounces and participant delivered in a medical facility by a physician

   Lower tertile

1.0 (0.6–1.7)

   Central tertile

Referent

   Upper tertile

0.7 (0.4–1.2)

White, restricted

data:

   Lower tertile

1.1 (0.5–2.4)

   Central tertile

Referent

   Upper tertile

1.4 (0.6–2.0)

[20]

2006

PCC

2,386

2,502

Poland

<2,500

Referent

Adjusted for: age, education, age at menarche, menopausal status and age at menopause, age at first full-term pregnancy, number of full-term pregnancies, family history of breast cancer among first-degree relatives, mammography screening, and current body mass index. Lower birth weight (<2,500 g) carries greater risk than birth weight of 2,500–4,000 g among women under 45 years old

2,500–4,000

1.22 (0.92–1.62)

>4,000

1.54 (1.08–2.19)

(p-trend = 0.01)

[37]

2006

PCC

1,166

2,105

USA

<2,495

1.19 (0.85–1.66)

Adjusted for age (years), education (years), race, body mass index, history of breast benign disease, family history of breast cancer, lactation (months), age at menarche (years), age at first full-term pregnancy (years), age at menopause (years), parity

2,495–3,130

Referent

3,131–3,855

0.97 (0.75–1.25)

>3,855

1.03 (0.74–1.44)

Cohort studies

[21]

1999

LCohort

57

152,590

Sweden

<2,500

Referent

Standardization for sex, age, and age-specific incidence rate

2,500–3,999

1.3 (0.6–2.4)

4,000–4,499

1.2 (0.0–6.7)

≥ 4,500

1.3 (0.7–2.3)

[22]

2000

Cohort

37

2,221

UK

All ages

Adjusted for age. P for trend = 0.03 among premenopausal women

   <3,000

Referent

   3,000–3,499

1.05 (0.41–2.71)

   3,500–3,999

1.76 (0.72–4.33)

   ≥ 4,000

2.02 (0.59–6.90)

Premenopausal ages

   <3,000

Referent

   3,000–3,499

1.99 (0.40–9.86)

   3,500–3,999

3.26 (0.69–15.36)

   ≥ 4,000

5.65 (0.95–33.84)

[38]

2001

LCohort

177

3,447

Sweden

≤ 2,000

Referent

Crude hazard ratios

2,001–2,500

1.4 (0.6–3.4)

2,501–3,000

1.9 (0.8–4.3)

3,001–3,500

1.5 (0.6–3.5)

≥ 3,501

1.9 (0.7–5.0)

[39]

2001

Cohort

62

1260

Sweden

≤ 3,000

Referent

Singleton only; adjusted for gestational age and cohort membership

3,010–3,349

1.16 (0.47–2.87)

3,350–3,590

1.65 (0.71–3.86)

3,600–3,960

1.58 (0.67–3.72)

≥ 4,000

1.57 (0.67–3.64)

[23]

2003

LCohort

63

5,352

Sweden

<3,000

Referent

Crude ORs;P for trend = 0.01

3,000–3,499

1.46 (0.60–3.43)

3,500–3,999

2.09 (0.90–4.85)

≥ 4,000

2.78 (1.10–7.15)

[24]

2003

LCohort

2,334

106,504

Denmark

1,000 g increase

9 (0.02–17)%

Adjusted for age and calendar period. Additional adjustment for parity and age at first birth did not indicate confounding

[25]

2003

LCohort

39

1483

Sweden

500–1,999

1.14 (0.70–1.85)

Standardized incidence ratio (expected/observed)

2,000–2,999

0.71 (0.40–1.15)

≥ 3,000

2.55 (1.03–5.25)

[26]^a

2004

LCohort

2,074

91,601

Denmark

Median of each quintile

Adjusted for age and calendar period. No change in estimates when additionally adjusted for parity and age at first birth

   2.5

Referent

   3.0

0.98 (0.85–1.13)

   3.4

1.06 (0.93–1.20)

   3.6

1.05 (0.87–1.27)

   4.0

1.17 (1.02–1.33)

[27]

2004

Cohort

59

2,176

UK

<3,000

Referent

Adjusted for age; P for trend = 0.03

3,000–3,499

1.37 (0.34–5.47)

3,500–3,999

2.18 (0.58–8.21)

≥ 4,000

5.03 (1.13–22.47)

[28]

2005

LCohort

311

16,011

USA

<3,040

Referent

Adjusted for year of birth

3,040–3,310

1.4 (1.0–2.1)

3,320–3,550

1.0 (0.6–1.5)

3,560–3,830

1.3 (0.9–1.9)

≥ 3,840

1.5 (1.0–2.2)

[29]^a

2005

LCohort

367

5,346

Sweden

<50 years

   <3,000

Referent

   3,000–3,499

1.81 (0.77–4.26)

   3,500–3,999

2.66 (1.09–6.46)

   ≥ 4,000

4.00 (1.49–10.72)

≥ 50 years

   <3,000

Referent

   3,000–3,499

0.86 (0.62–1.19)

   3,500–3,999

1.06 (1.20–3.34)

   ≥ 4,000

0.91 (0.57–1.46)

[40]

2006

Cohort

97

5,847

USA

<3,000

0.98 (0.61–1.60)

Adjusted for age

3,000–3,499

Referent

≥ 3,500

1.09 (0.66–1.80)

[30]

2006

Cohort

3,140

91,601

USA

Premenopause

Adjusted for age: P for trend = 0.019

   <2,495

0.69 (0.50–0.94)

   2,495–3,130

0.79 (0.64–0.97)

   3,131–3,810

0.76 (0.63–0.93)

   >3,810

Referent

Postmenopause:

Adjusted for age: P for trend = 0.99

   <2,495

1.04 (0.88–1.23)

   2,495–3,130

1.00 (0.87–1.14)

   3,131–3,855

1.05 (0.93–1.20)

   >3,855

Referent

[31]

2006

Cohort

209

1,024

USA

<2,500

0.9 (0.5–1.6)

Hazard ratio; adjusted for age at diagnosis, diagnosis year, stage at diagnosis, and birth order, with exception of birth order, which is adjusted for maternal age

2,500–3,999

Referent

≥ 4,000

1.8 (1.0–3.1)

(P trend = 0.1)

[41]

2007

Cohort

657

38,566

Sweden

<2,500

0.65 (0.43–0.99)

Adjusted for adult body mass index

2,500–3,000

1.04 (0.86–1.25)

>3,000

Referent