 Premenopausal patients with estrogen receptor ER andor progesterone receptor PR positive disease receive oral tamoxifen once daily for 5 years beginning at the time of radiotherapy or within 6 weeks after the completion of chemotherapy. Postmenopausal patients with ER andor PR positive disease receive an aromatase inhibitor e.g., anastrozole, letrozole, or exemestane or tamoxifen followed by an aromatase inhibitor once daily for up to 10 years. 