Hypothyroidism associated with reduced risk.(of breast cancer)

2003 MAY 1 - (NewsRx.com & NewsRx.net) -- Women with a common thyroid gland disorder appear to have a reduced chance of developing invasive breast cancer, say researchers at The University of Texas M.D. Anderson Cancer Center.

In a retrospective case-control study of 2226 females, researchers found that women newly diagnosed with breast cancer were 57% less likely to have hypothyroidism compared to a control group of healthy women.

Of further note, researchers said that the breast cancer found in 80 participants who had a history of hypothyroidism was of a less aggressive, indolent variety that was sensitive to estrogen. Also, these women were generally older when first diagnosed with the disease.

"These intriguing findings suggest a possible biological role of thyroid hormone in women with breast cancer that could offer some prognostic or therapeutic value, perhaps suggesting novel preventive strategies," said Massimo Cristofanilli, MD, an assistant professor in the department of breast medical oncology. The results of the study were published in the Proceedings for the 2003 Annual Meeting of the American Association for Cancer Research.

The influence of thyroid gland disease on breast cancer has been debated for some time, but this is the first study to examine the characteristics of invasive breast cancer in patients with hypothyroidism and compare the incidence of this common condition with a carefully selected matched control group, Cristofanilli said. Other smaller studies have focused on a population of women with several thyroid conditions (such as hypothyroidism, hyperthyroidism, thyroid cancer and others) and reported controversial results on the incidence of breast ...