Cost-effectiveness implications of increased survival with anastrozole in the treatment of advanced breast cancer

Anastrozole (Arimidex*) has a survival benefit compared with megestrol acetate in postmenopausal women with advanced breast cancer who have failed on tamoxifen. It was felt appropriate that such a clinical finding should be subjected to economic evaluation. A cost-effectiveness analysis was undertaken from the viewpoint of a third-party payer, of the data from a combined analysis of two clinical studies. The outcome measures were duration of drug treatment and life years gained. The incremental cost effectiveness ratio (ICER) of anastrozole was £1,608 per life year gained based on UK NHS drug prices in April 1998. Sensitivity analysis showed that the ICER could vary between £5 and £1,643, depending on relative drug costs in a number of countries, between £1,056 and £1,761, depending on the method used to calculate duration of treatment and survival, and could increase to £3,730, based on treatment provided during the extra period of survival. Anastrozole is a highly cost-effective alternative to megestrol acetate for postmenopausal women with advanced breast cancer.