Thyroid autoimmunity-breast cancer link independent of surgical stress
Italian investigators have confirmed that there is a strong link between thyroid autoimmunity and breast cancer, and that this link is independent of the effects of mastectomy-induced stress.
"The present data call attention to the usefulness of screening for autoimmune thyroid disorders in patients with nodular breast disease selected for surgery," E Giustarini, from the University of Pisa, and co-workers say.
Writing in the European Journal of Endocrinology, the team explains that a strong relationship between thyroid autoimmune disorders and breast cancer is known, yet studies have generally been performed in patients 20-30 days after mastectomy and therefore may be confounded by the effects of stress.
To address this issue, Giustarini et al compared the levels of thyroid markers and function in 61 women aged an average of 52 years with nodular breast disease who were selected for breast surgery with 100 healthy age- and gender-matched controls.
Thirty-six (59%) of the women with nodular breast disease were diagnosed with breast cancer and 25 (41%) had benign breast disease.
Levels of thyroperoxidase antibodies were significantly higher in women with breast cancer than among women with benign breast disease and controls, at 33.3% versus 20% and 8%, respectively.
A similar pattern of results was observed for levels of thyroglobulin antibodies, at 33.3% versus 16% and 12%, for women with breast cancer compared to those with benign breast disease and controls, respectively.
Whereas diffuse hypoechogenicity of the thyroid gland was detected in 20 (56%) of the 36 patients with breast cancer, it was found in only seven (28%) of the women who had benign breast disease.
Furthermore, thyroid autoimmunity "consistent with the hypoechogenic pattern of thyroid gland" was identified in 67% of women with breast cancer compared with only 36% of those with benign breast disease, the scientists report.
"The results of this study confirm a strong relationship between thyroid autoimmunity and breast cancer. For the first time we have demonstrated that this relationship is also present before surgery and anti-tumoral treatment," Giustarini and colleagues conclude.