Hormone Replacement Therapy and Breast Cancer Risk
Author Information
Author(s): Ewertz M, Mellemkjaer L, Poulsen A H, Friis S, Sørensen H T, Pedersen L, McLaughlin J K, Olsen J H
Primary Institution: Aalborg Hospital, Aarhus University
Hypothesis
Does hormone replacement therapy (HRT) increase the risk of developing breast cancer in women aged 50 years or more?
Conclusion
The study confirms that hormone replacement therapy increases the risk of developing breast cancer in women aged 50 years or more.
Supporting Evidence
- HRT use was associated with a relative risk of 1.61 for breast cancer in women aged 50 years or more.
- The risk increased with the duration of HRT use and decreased after stopping HRT for 5 years.
- Breast cancer incidence was nonsignificantly lower among women aged 40-49 who used HRT.
Takeaway
Using hormone replacement therapy can make older women more likely to get breast cancer, especially if they use it for a long time.
Methodology
The study used longitudinal data from a population-based prescription database and the Danish Cancer Registry to examine breast cancer risk in relation to HRT use.
Potential Biases
Potential uncontrolled bias inherent in observational studies may affect the risk estimates.
Limitations
The study lacked information on age at menopause and body mass index (BMI), which could confound the results.
Participant Demographics
The study included 78,380 women aged 40-67 years from North Jutland, Denmark.
Statistical Information
P-Value
1.61
Confidence Interval
1.38–1.88
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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