Letrozole was significantly superior to tamoxifen in TTP, TTF, ORR, and clinical benefit rate. Our results support its use as first-line endocrine therapy in postmenopausal women with advanced breast cancer.

This study shows that letrozole is more effective than tamoxifen as preoperative therapy in postmenopausal patients with ER and/or PgR positive primary untreated breast cancer and is at least as well tolerated.

This study documents the superiority of letrozole over tamoxifen in first-line endocrine therapy in postmenopausal women with advanced breast cancer.

Patients with normal serum HER-2/neu receiving letrozole demonstrated a significantly greater ORR and CB and longer TTP and TTF than patients receiving tamoxifen. Although in patients with elevated serum HER-2/neu there was no significant difference between letrozole and tamoxifen in ORR or CB, there was a strong trend favoring longer TTP and significantly longer TTF with letrozole.