From: Intrauterine environments and breast cancer risk: meta-analysis and systematic review
Type of study | Ref. | Year | Design | Cases | Controls (or cohort) | Country/place of study | Birthweight (g) | OR (95% CI) | Comments |
---|---|---|---|---|---|---|---|---|---|
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 |  |