Wyeth study: conjugated estrogen does not pose breast cancer risk, in some cases shows benefit

US drug major Wyeth has reported data showing that estrogen does not increase women's risk of breast cancer, which is one of the main concerns that stops women choosing hormone replacement to combat the menopause.

The data, published in the April 11 issue of the Journal of the American Medical Association, show that, in the estrogen-alone sub-study of the New Jersey-headquartered firm's Women's Health Initiative clinical program, conjugated estrogens at 0.625mg doses did not increase the risk of developing breast cancer in a postmenopausal study population.

The authors of the JAMA paper also noted the possibility of a protective effect against breast cancer incidence in three groups: women with a low five-year estimated risk of developing breast cancer as measured by the Gail Risk Score; women with no first-degree relatives with breast cancer; and women with no prior history of benign breast disease.