Environment and Breast Cancer: Science Review

Evidence From Humans
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Birth characteristics and adult cancer incidence: Swedish cohort of over 11,000 men and women
McCormack, V. A., dos Santos Silva, I., Koupil, I., Leon, D. A., Lithell, H. O. Int J Cancer. 2005. 115:4, 611-7.
Topic area
Early life exposures
Study design
Prospective cohort
Funding agency
Other: UK Medical Research Council, Swedish Counci
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Number in Cohort
Cohort: 5346
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Uppsala Birth Cohort Study In: Women born from singleton birth in the Uppsala Academic Hospital during 1915-1929. Ex: Women who died or emigrated before the start of follow-up 1 November 1960, women previously diagnosed with cancer, records without birth weight or gestational age data, or with unreliable gestational age of under 30 weeks
Exposures investigated
Birthweight, birth length, gestational age
How exposure was measured
Other: Birth records
Statistical Analysis
Breast cancer outcome investigated
Primary incident breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
BMI, race, parity, alcohol consumption, family history of breast disease
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Proportional hazard model adjusted for sex and socioeconomic factors at birth and in adulthood. Adjusted HR with 95% CI, Birthweight: >=4000g versus <3000g; birth length: Effect of standard deviation (2.2cm) increase in birth length for gestational age; g
Strength of associations reported
<50: Birthweight: 4.00 (1.49-10.92); birth length: 1.41 (1.07-1.86); gestational age: 0.94 (0.83-1.07)
>=50: Birthweight: 0.91 (0.57-1.46) ; birth length: 1.05 (0.93-1.20); gestational age: 0.99 (0.93-1.04)
Results Comments
Positive association between birth weight and birth length for gestational age with breast cancer under age 50 years, but no association over age 50.
Author address
Department of Epidemiology and Population Health, London School of Hygiene & Tropical Medicine, London, United Kingdom. valerie.mccormack@lshtm.ac.uk