Main aim was to estimate the association between use of exogenous hormones and breast cancer (BC) risk in a large population-based survey, and to assess the representativeness and overall validity of the data.
Methods
The survey 'Women's Health and Use of Hormones' was conducted in Finland in 2009, including 7,000 BC cases and 20,000 matched population controls. Conditional logistic regression was used to estimate odds ratios and their 95 % confidence interval. For validation, exposure prevalences were compared with population data from Statistics Finland and two large population-based surveys.
Results
We found positive associations with BC risk and exclusive use of hormone-releasing intrauterine device (HR IUD) in postmenopausal women (1.48, 95 % CI 1.10-1.99), when compared to never-users of any hormonal contraceptive and considering only prediagnostic use in cases. Regarding use of other hormonal contraceptives (HC), a positive association between long HC use (≥2 years) and BC was observed in both groups, OR being 1.37 (95 % CI 1.12-1.68) for premenopausal and 1.11 (95 % CI 1.03-1.20) for postmenopausal women, when compared to never-users of other HC.
Conclusions
Observed association between HR IUD use and risk of BC in postmenopausal women is worrying and deserves further attention. Selection bias seemed not to explain this result. Considering the increasing popularity of HR IUD use in, e.g., USA, impact of possible adverse effects in public health could be significant.
hormonal contraceptives breast cancer risk population-based survey, levonorgestrel intrauterine device breast cancer postmenopausal women, hormone-releasing IUD breast cancer risk association, exogenous hormones breast cancer Finland case-control study, hormonal contraception long-term use breast cancer odds ratio, HR IUD postmenopausal breast cancer risk 1.48, oral contraceptive use duration breast cancer premenopausal, Heikkinen hormonal contraceptive breast cancer Finland, Mirena IUD breast cancer risk postmenopausal women, hormonal contraceptive exposure validation population-based data
PMID 26667320 26667320 DOI 10.1007/s10552-015-0702-5 10.1007/s10552-015-0702-5
Cite this article
Heikkinen, S., Koskenvuo, M., Malila, N., Sarkeala, T., pukkala, E., & Pitkaniemi, J. (2016). Use of exogenous hormones and the risk of breast cancer: results from self-reported survey data with validity assessment. Cancer causes & control : CCC, 27(2), 249-258. https://doi.org/10.1007/s10552-015-0702-5
Heikkinen S, Koskenvuo M, Malila N, Sarkeala T, pukkala E, Pitkaniemi J. Use of exogenous hormones and the risk of breast cancer: results from self-reported survey data with validity assessment. Cancer Causes Control. 2016;27(2):249-258. doi:10.1007/s10552-015-0702-5
Heikkinen, Sanna, et al. "Use of exogenous hormones and the risk of breast cancer: results from self-reported survey data with validity assessment." Cancer causes & control : CCC, vol. 27, no. 2, 2016, pp. 249-258.
Keywords
Contraceptive Agents, Female, Contraceptives, Oral, Hormonal, Drug Implants
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