Breast Cancer Risk and Reproductive Factors in Denmark
Author Information
Author(s): M. Ewertz, S.W. Duffy
Primary Institution: Danish Cancer Society, Danish Cancer Registry
Hypothesis
What is the relationship between reproductive factors and breast cancer risk?
Conclusion
The study confirmed that full-term pregnancies protect against breast cancer, while never being pregnant increases the risk.
Supporting Evidence
- Women who never had a full-term pregnancy had a 47% increased risk of breast cancer.
- An early terminated first pregnancy was associated with a 43% increased risk.
- Having a natural menopause after age 54 was linked to a 67% increased risk.
Takeaway
Having babies can help protect women from breast cancer, but if a woman never has a baby, her risk goes up.
Methodology
Population-based case-control study with self-administered questionnaires.
Potential Biases
Selection bias is unlikely as both cases and controls were drawn from the general population.
Limitations
The study may have limitations related to recall bias and the small number of women exposed to oral contraceptives.
Participant Demographics
Women aged less than 70 years diagnosed with breast cancer in Denmark.
Statistical Information
P-Value
0.01
Confidence Interval
1.10-1.84
Statistical Significance
p<0.05
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