Fulvestrant: A New Treatment Option for Advanced Breast Cancer - Tolerability Versus Existing Agents

The document from 2006 reviewed the tolerability and effectiveness of fulvestrant, a new estrogen receptor antagonist, in treating postmenopausal women with hormone receptor-positive advanced breast cancer (ABC). In phase III trials involving 851 women, fulvestrant, given as a once-monthly 250 mg intramuscular injection, was at least as effective as anastrozole and was well tolerated, with fewer joint disorders and hot flushes compared to non-steroidal aromatase inhibitors (AIs) and tamoxifen, respectively. Over 1100 women had received fulvestrant in clinical studies, showing a predictable tolerability profile with mild or moderate adverse events. Fulvestrant does not have the androgenic side-effects of steroidal AIs or the proliferative effect on the endometrium like tamoxifen, reducing the risk of endometrial cancer. The review concluded that fulvestrant is a well-tolerated treatment option that could delay the need for chemotherapy, potentially improving the quality of life for patients with ABC. Further trials were planned to assess its long-term benefits in the adjuvant setting.