Environment and Breast Cancer: Science Review


Evidence From Humans
 
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Birth characteristics of premenopausal women with breast cancer
Le Marchand, L., Kolonel, L. N., Myers, B. C., Mi, M. P. Br J Cancer. 1988. 57:4, 437-9.
Topic area
Early life exposures
Study design
Population based case-control
Study Participants
Number of Cases
153 (74 for birth weight, 148 for paternal age)
Menopausal Status
The menopausal status of women included in this study is listed here.
Yes
Number of Controls
Controls: 461 (245 for birth weight, 457 for gestational age, 447 for paternal age)
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: cases: Microscopically-confirmed breast cancers born in Hawaii after 1941, who were reported between 1960 and 1984 to the Hawaii Tumour Registry, controls were selected among the participants in a health survey conducted among 2% random sample of the state population between 1975 and 1980 and matched to each case on ethnic origin and year of birth Ex: cases for which matched controls could not be found
Exposure Investigated
Exposures investigated
Birth weight, gestational age, maternal age, maternal age for younger subjects (before age 33), paternal age , preeclampsia
How exposure was measured
Other: Birth records
Exposure assessment comment
accuracy of birth records (birth weight was not reported before 1946 and very few complications: 2% of all pregnancies)
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.
Matched for race
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, parity, alcohol consumption, family history of breast cancer
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
No
Description of major analysis
Conditional logistic regression controlled for age, year of birth and ethnicity. OR with 95% CI: each continuous variable was categorized into approximate quartiles or tertiles; birthweight (tertiles): 3341-4451g versus 1161-2948g, maternal age (quartiles
Strength of associations reported
Birth weight: 0.76 (0.41-1.43); maternal age: 1.66 (0.99-2.78); maternal age for younger subjects: 2.21 (1.02-4.80); Gestational age: 1.16 (0.50-2.66); Paternal age: 1.40 (0.81, 2.41); Preeclampsia: 3.46 (0.86, 13.90)
Results Comments
Only history of complication during the index pregnancy yielded an odds ration notably different from 1. The analysis of age of mothers by age at diagnosis showed that the J shaped association with maternal age was more marked in patients diagnosed at a younger age.
Author address
Epidemiology Program, Cancer Research Center of Hawaii, University of Hawaii, Honolulu 96813.