HIGH-FREQUENCY OF ADENOMYOSIS IN POSTMENOPAUSAL BREAST-CANCER PATIENTS TREATED WITH TAMOXIFEN

Pathologic evaluation for adenomyosis in uterine specimens as well as demographic characterstics, health habits and risk factors for endomet rial cancer were compared in 28 postmenopausal breast cancer patients with tamoxifen (TAM) treatment and in 11 similar patients without TAM treatment in order to determine the association between postmenopausal TAM exposure and the frequency of adenomyosis. The same comparison wa s also made between TAM-treated patients with adenomyosis and TAM-trea ted patients without adenomyosis. Adenomyosis was histologically diagn osed in 53.6% TAM-treated patients and in 18.2% non-TAM patients. Over all, there were no significant statistical differences in all paramete rs tested between the 2 groups, as well as between the TAM-treated pat ients with adenomyosis and the TAM-treated patients without adenomyosi s. It can be concluded that adenomyosis was significantly more common among postmenopausal breast cancer patients who were treated with TAM as compared to similar patients without TAM treatment (p = 0.0186). Th is significant high rate of adenomyosis may be attributed to the conti nuous and unopposed exposure to TAM. It is, however, impossible to pre dict which postmenopausal breast cancer patient will develop adenomyos is after treatment with TAM.