FaCD Online Syndrome Fact Sheet

Last updated: 16 May 2008

Name: Endometriosis, Familial

Mode of Inheritance: multifact? / AD?

OMIM number: 131200  


ENDO1, mapped to 10q26

Tumor features

breast cancer

Non-tumor features



Women with endometriosis have a tenfold increased risk of endometriosis in their first-degree relatives[1]. In addition, there appears to be an association between endometriosis and familial clustering of breast cancer. In a series of 352 endometriosis patients, a positive family history of breast cancer was detected in 27%. The relative risk of women with endometriosis and positive family history of breast cancer was 6.9 (95% CI, 3.4-14.1). Endometriosis was associated with the risk of first-degree relatives of breast cancer (OR=5.69; 95% CI, 2.4-13.3) and more specifically with the risk of breast cancer in mothers (OR=6.3; 95% CI, 2.2-17.8) and in maternal aunts (OR=5.9; 95% CI, 1.3-72.9).[2].

With respect to personal history of endometriosis and breast cancer risk, in a series of 1,978 Danish women with endometriosis, the overall rate ratio for breast cancer after endometriosis was 1.00[3]. The risk for breast cancer increased with age at diagnosis of endometriosis. Women diagnosed with endometriosis was diagnosed <40 years had a reduced risk for breast cancer and those diagnosed at older ages tended to have an increased risk for breast cancer. The authors speculated that reduced breast cancer risks observed among young women might reflect their exposure to drugs with antiestrogenic effects, whereas the increased risk among postmenopausal women might be due to shared risk external factors or an altered endogenous estrogen.


[1] Matalliotakis IM, Arici A, Cakmak H, Goumenou AG, Koumantakis G, Mahutte NG. Familial aggregation of endometriosis in the Yale Series. Archives of gynecology and obstetrics 2008; .
[2] Matalliotakis IM, Cakmak H, Mahutte N, Goumenou AG, Koumantakis G, Arici A. The familial risk of breast cancer in women with endometriosis from Yale series. Surgical oncology 2008; .
[3] Bertelsen L, Mellemkjaer L, Frederiksen K, Kjaer SK, Brinton LA, Sakoda LC, van Valkengoed I, Olsen JH. Risk for breast cancer among women with endometriosis. International journal of cancer 2007; 120(6):1372-5.