ABSTRACT
BACKGROUND: Fibroadenomas are the most frequent benign breast neoplasias. Although they are hormone-dependent, no hormonal treatment of proven effectiveness is available for these neoplasias. The objective of the present study was to evaluate the ultrasonographic volume of fibroadenomas in premenopausal women treated with tamoxifen at the doses of 5, 10, 20 mg/day or with placebo for 50 days, starting on the 1st day of the menstrual cycle. METHODS: A prospective and randomized study was conducted on 62 eumenorrheic women aged 15 to 45 years with no hormonal treatment or pregnancy during the last 12 months, with a clinical, cytologic and ultrasonographic diagnosis of fibroadenoma, later followed by a biopsy diagnosis. The patients were divided at random into 4 groups: A (n=15; placebo), B (n= 16; 5 mg/day tamoxifen), C (n=16; 10 mg/day tamoxifen), and D (n=15; 20 mg/day tamoxifen). Fibroadenoma volume was measured by ultrasound at 3 different times: on the 22nd day of the cycle that preceded the beginning of tamoxifen treatment, after 1 month of treatment, and on the day of the biopsy (50th day). The mean volume obtained for groups A, B, C and D was 3, 3.3, 1.9, and 2.3 cm3, respecti-vely. RESULTS: Statistical analysis revealed a significant reduction in nodule size only in group D (p=0.0024). CONCLUSIONS: We conclude that tamoxifen significantly reduced fibroadenoma volume when administered for 50 days at the dose of 20 mg/day. Further clinical studies are needed using the drug for a longer period of time, and in order to exclude the need for unnecessary treatment in some women.
