A systematic review including 3 RCTs with a total of 1 648 subjects was abstracted in DARE. Using the individual survival data derived from the original survival graphs, aromatase inhibitors significantly prolonged survival (relative risk of death 0.79; 95% Cl: 0.69 to 0.91). The analysis was performed on an intention to treat basis, with 803 patients treated with aromatase inhibitors and 845 patients treated with megestrol. The mean survival gain per patient was 4.1 months.
A retrospective non-randomised comparison between letrozole, anastrozole and exemestane showed better survival among exemestane- treated patients, followed by letrozole-treated patients, then anastrozole-treated patients. The megestrol group had a better survival pattern in the exemestane study, compared with the letrozole and anastrozole trial.