Anastrozole: licence extension. No advantage over tamoxifen in advanced-stage breast cancer

Abstract

(1) The reference hormone therapy for postmenopausal women with advanced-stage hormone-sensitive breast cancer is tamoxifen, an anti-oestrogen, at an oral dose of 20 mg/day for 5 years. (2) Anastrozole, an aromatase inhibitor, was previously indicated for second-line use in this setting, after failure of tamoxifen. This restriction has now disappeared from the French marketing terms. (3) The clinical file on anastrozole in this indication includes two trials comparing anastrozole (1 mg/day) with tamoxifen (20 mg/day). After follow-up of less than 2 years, neither trial shows that anastrozole improves the duration or quality of survival relative to tamoxifen. (4) In these trials the adverse events profiles of tamoxifen and anastrozole did not differ. Articular adverse events were more frequent on anastrozole (10.5% versus 5.7%). (5) In practice, anastrozole remains a second-line treatment for advanced-stage breast cancer in postmenopausal women. Anastrozole therapy is 9 times as expensive as generic tamoxifen in France.