Oral contraceptives, postmenopausal hormones, and risk of asynchronous bilateral breast cancer: The WECARE study group Journal Article


Authors: Figueiredo, J. C.; Bernstein, L.; Capanu, M.; Malone, K. E.; Lynch, C. F.; Anton-Culver, H.; Stovall, M.; Bertelsen, L.; Haile, R. W.; Bernstein, J. L.
Article Title: Oral contraceptives, postmenopausal hormones, and risk of asynchronous bilateral breast cancer: The WECARE study group
Abstract: Purpose To investigate whether oral contraceptive (OC) use and postmenopausal hormones (PMH) are associated with an increased risk of developing asynchronous bilateral breast cancer among women diagnosed with breast cancer younger than 55 years. Patients and Methods The WECARE (Women's Environment, Cancer, and Radiation Epidemiology) study is a population-based, multicenter, case-control study of 708 women with asynchronous bilateral breast cancer and 1,395 women with unilateral breast cancer. Risk factor information collected during a telephone interview focused on exposures before and after the first breast cancer diagnosis. Treatment and tumor characteristics were abstracted from medical records. Multivariable conditional logistic regression was used to estimate rate ratios (RR) and 95% CIs. Results OC use before the first breast cancer diagnosis was not associated with risk of asynchronous bilateral breast cancer (RR = 0.88; 95% CI, 0.67 to 1.16). OC use after breast cancer diagnosis was also not significantly associated with risk (RR = 1.56; 95% CI, 0.71 to 3.45). Risk did not increase with longer duration of use or among women who had begun using OCs at a younger age. No evidence of an increased risk of asynchronous bilateral breast cancer was observed with PMH use before (RR = 1.21; 95% CI, 0.90 to 1.61) or after breast cancer diagnosis (RR = 1.10; 95% CI, 0.67 to 1.77). Neither duration nor type of PMH were associated with risk. Age at and time since first breast cancer diagnosis did not substantially affect these results. Conclusion This study provides no strong evidence that OC or PMH use increases the risk of a second cancer in the contralateral breast.
Keywords: survivors; trial; women; brca2 mutation carriers; progestin; replacement therapy; collaborative reanalysis
Journal Title: Journal of Clinical Oncology
Volume: 26
Issue: 9
ISSN: 0732-183X
Publisher: American Society of Clinical Oncology  
Date Published: 2008-03-01
Start Page: 1411
End Page: 1418
Language: English
ACCESSION: WOS:000254178600006
DOI: 10.1200/jco.2007.14.3081
PROVIDER: wos
PUBMED: 18250348
Notes: --- - Article - "Source: Wos"
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MSK Authors
  1. Marinela Capanu
    211 Capanu
  2. Jonine L Bernstein
    104 Bernstein