Mechanism Of Action

Tamoxifen works by interfering with the effects of estrogen in the breast tissue. If a patient is determined to have estrogen positive (ER+) breast cancer, estrogen may be fueling the growth of cancer cells in the breast. Tamoxifen binds to the cancer cells in the breast preventing cancer cells from binding with estrogen, thereby keeping the cancer cells from reproducing. Tamoxifen works by interfering with the effects of estrogen in the breast tissue. If a patient is determined to have estrogen positive (ER+) breast cancer, estrogen may be fueling the growth of cancer cells in the breast. Tamoxifen binds to the cancer cells in the breast preventing cancer cells from binding with estrogen, thereby keeping the cancer cells from reproducing.