WESTPORT, CT (Reuters Health) – Changes in mammographic breast density related to hormone replacement therapy (HRT) vary according to the regimen, with combined continuous HRT causing the greatest increases, Turkish physicians report.
According to the results of a separate prospective study by physicians in Italy, suspending HRT for about 3 weeks reverses such increases in breast density. Both articles appear in the September issue of Fertility and Sterility.
Dr. Fatih Sendag and associates, of Ege University in Izmir, Turkey, evaluated sequential mammograms of 216 women using postmenopausal HRT. Mammographic density did not increase significantly after initiation of estrogen-only or cyclic combined postmenopausal HRT, the researchers found. They report a similar finding for women using tibolone.
Nineteen of 61 patients (31%) exhibited increased breast density after receiving continuous combined HRT, compared with one of the 44 receiving cyclic combined HRT (2%) and three of the 76 receiving estrogen only (4%). No changes were observed in the 35 patients using tibolone.
Dr. Sendag 's group notes that "increased breast density may reduce mammographic sensitivity and prevent the diagnosis of clinically occult cancers." The investigators suggest that tibolone may be the preferable regimen for HRT, especially for patients with a history of breast cancer or whose breasts are dense even before beginning HRT.
In the second study, Dr. Nicola Colacurci and colleagues at the Second University of Naples, Italy, treated 39 naturally menopausal women with continuous combined HRT. Thirty-seven women in surgical menopause received estrogen only, and 21 women received no HRT.
Approximately half of the women treated with HRT discontinued treatment for an average of 21 to 22 days before a second mammography was performed 12 months after the baseline mammogram.
Seven of the 19 patients receiving continuous combined HRT and four of the 19 receiving estrogen exhibited increased density in the second mammogram. However, only one of 20 and one of 18 women in each group, respectively, who suspended treatment exhibited increased density.
Dr. Colacurci and her associates conclude that "the cessation of the replacement therapy for a brief period may be useful for enhancing the sensitivity of the mammographic test, especially when a progestin is added to the estrogen."