Anastrozole

Excerpt

Anastrozole is one of the new third-generation aromatase inhibitors which have significantly added to our increasingly robust armamentarium of hormonal therapies for breast cancer. In advanced disease in postmenopausal women, anastrozole showed a significant increase in time to progression and a superior toxicity profile compared with tamoxifen. Given these results and the importance of hormonal therapy in the management of early stage breast cancer, anastrozole was brought into clinical trials in the adjuvant setting. Early results from the Arimidex, Tamoxifen Alone or in Combination (ATAC) trial at a median follow-up of 33 months demonstrate that, compared with tamoxifen, anastrozole significantly reduces the relative risk of disease recurrence in estrogen receptor-positive patients by 22% (p = 0.005) and reduces the relative risk of developing a secondary breast cancer by 58% (p = 0.007). Overall, these results have translated into a 2% disease-free survival advantage at 3 years favouring the anastrozole arm. Anastrozole was also associated with significantly fewer adverse events; importantly, this included a lower incidence of endometrial cancer and thromboembolic events. Based on these results, the US Food and Drug Administration has approved anastrozole for use in the adjuvant setting in postmenopausal women with estrogen receptor-positive breast cancer. …