Changes in apoptosis, mitosis, Her-2, p53 and Bcl2 expression in breast carcinomas after short-term tamoxifen treatment.

The short-term (7 days) effect of tamoxifen on apoptosis and mitosis index, p53, Bcl2 and Her-2/neu/c-erb2 expression in invasive ductal mammary carcinoma was studied histologically in the diagnostic biopsy and surgically removed tumor tissue of 10 patients. Following tamoxifen treatment expression of HER-2 and p53 decreased but Bcl2 remained unchanged. Mitotic activity decreased slightly, but not significantly. Apoptotic activity increased in six cases in the second sample compared to the values measured of the first biopsy. These changes may be attributed to the effect of antiestrogen therapy.