Risk for breast cancer among women with endometriosis

Bertelsen L, Lisbeth Bertelsen, Lene Mellemkjaer, Lene Mellemkjær, Kirsten Frederiksen, Frederiksen K, Susanne K. Kjær, Susanne K Kjaer, Louise A. Brinton, Brinton LA, Lori C. Sakoda, Sakoda LC, Irene G. M. van Valkengoed, Irene van Valkengoed, Jørgen H. Olsen
International journal of cancer · 2006 · vol. 120(6) , pp. 1372–1375 · doi:10.1002/ijc.22490 · PMID:17187365 · W2065428692
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This case-cohort study found no overall association between endometriosis and breast cancer risk, but identified age-dependent risks, with younger women showing reduced risk and older women showing increased risk.

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Abstract

Although several risk factors are common to endometriosis and breast cancer, the results of observational studies of an association have so far been inconsistent. We evaluated the relationship between endometriosis and breast cancer on the basis of data on selected cancers and medical histories from the Danish nationwide cancer and hospital registries used in a large case-cohort study. A total of 114,327 women were included in the study of whom 1,978 women had received a diagnosis of endometriosis and 16,983 had had a diagnosis of breast cancer between 1978 and 1998. Of the women with endometriosis, 236 subsequently received a diagnosis of breast cancer. The crude overall rate ratio for breast cancer after endometriosis was 1.00 and after adjustment for reproductive factors, calendar-period, bilateral oophorectomy and benign breast disease, the rate ratio was 0.97 (95% confidence interval, 0.85-1.11). The risk for breast cancer increased with age at diagnosis of endometriosis, so that women in whom endometriosis was diagnosed at a young age (approximately or =40 years) tended to have an increased risk for breast cancer. The reduced risks observed among young women may reflect their exposure to drugs with antiestrogenic effects. The increased risk associated with endometriosis among postmenopausal women may be due to common risk factors between postmenopausal endometriosis and breast cancer or an altered endogenous estrogen.

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Condition tags

endometriosis

MeSH descriptors

Breast Neoplasms Endometriosis Adult Adult Breast Neoplasms Breast Neoplasms Breast Neoplasms Breast Neoplasms Cohort Studies Cohort Studies Denmark Denmark Denmark Endometriosis Endometriosis Endometriosis Female Female Humans Humans

Citation neighborhood (2-hop)

Papers in the corpus that this work cites (lower rings, blue) and that cite this one (upper rings, green). Dot size scales with the paper's in-corpus citation count — bigger dot = more influential within the endo/adeno field. Click a dot to open that paper. Outer rings show 2-hop neighbours — papers reached through the immediate citers/citees. [ collapse to 1-hop ]

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Cited by (50)

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