Environment and Breast Cancer: Science Review

Parental age at birth and risk of breast cancer in daughters: a prospective study among US women
Colditz, G. A., Willett, W. C., Stampfer, M. J., Hennekens, C. H., Rosner, B., Speizer, F. E. Cancer Causes Control. 1991. 2:1, 31-6.

Topic area
Early life exposures
Early life exposures
Study design
Prospective cohort
Prospective cohort
Funding agency
NCI
NCI

Study Participants
Number of Cases
1761 for maternal age, 1679 for paternal age
1761 for maternal age, 1679 for paternal age
Number in Cohort
Cohort: 118309
Cohort: 118309
Cohort participation rate
Not reported
Not reported
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Nurses Health Study
In: Registered nurses 30 to 55 years of age in 1976
Ex: women who reported breast cancer or other cancer (excluding nonmelanoma skin cancer) on the 1976 baseline questionnaire, women who reported a diagnosis of cancer other than nonmelanoma skin cancer on the 1978, 1980, or 1984 questionnaires were excluded from subsequent follow-up.
Comment about participation selection
Large cohort with biennial follow-up
Large cohort with biennial follow-up

Exposure Investigated
Exposures investigated
Maternal age, paternal age
Maternal age, paternal age
How exposure was measured
Questionnaire, self-administered
Questionnaire, self-administered
Exposure assessment comment
Misclassification due to self-report of parental age
Misclassification due to self-report of parental age

Statistical Analysis
Breast cancer outcome investigated
Primary incident breast cancer
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.
No
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.
Race, alcohol consumption
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
Adjusted RR with 95% CI, adjusted for age, time period, menopausal status, age at menarche, parity, age at first birth, BMI, family history, personal history of benign breast disease, maternal and paternal age: >39 years versus <20 years, separate analysi
Adjusted RR with 95% CI, adjusted for age, time period, menopausal status, age at menarche, parity, age at first birth, BMI, family history, personal history of benign breast disease, maternal and paternal age: >39 years versus <20 years, separate analysi
Strength of associations reported
Maternal age: 1.02 (0.72-1.45); paternal age: 0.90 (0.56-1.45)
Maternal age: 1.02 (0.72-1.45); paternal age: 0.90 (0.56-1.45)
Results Comments
Weak trend for increasing risk of breast cancer among daughters born to older mothers and no association with paternal age.
Weak trend for increasing risk of breast cancer among daughters born to older mothers and no association with paternal age.

Author address
Department of Medicine, Brigham and Women's Hospital, Boston, MA.
Department of Medicine, Brigham and Women's Hospital, Boston, MA.