Some drugs, like Tamoxifen changes a woman's estrogen level and can block the tumor growth and is used in adjuvant hormone therapy. Tamoxifen can reduce the risk of cancer recurring in patients whose tumors have been treated by surgery, radiation therapy, chemotherapy or all three. It is an orally taken anti-cancer drug that has been used in the treatment of breast cancer since the early 1970s. Tamoxifen is the most widely used cancer drug, with more than 3 million breast cancer patients receiving it. It is usually prescribed for a five-year period.
Tamoxifen is tolerated well by most patients.
However, it may cause short-term side effects related to the lowered levels of estrogen, such as hot flashes and some local effects. Another criterion that is important in planning adjuvant therapy is a woman's menopausal status. Studies have shown that the effectiveness of different types of adjuvant therapy for breast cancer depends on whether a woman is premenopausal or postmenopausal. Women who are premenopausal generally respond well to adjuvant chemotherapy. Also, women who are postmenopausal and hormone receptor positive generally respond to adjuvant hormone therapy.