Tamoxifen, Letrozole, Anastrozole, or Exemestane With or Without Chemotherapy as Treatment for Breast Cancer
The purpose of this study is studying whether giving tamoxifen citrate, anastrozole, letrozole, or exemestane works better with or without chemotherapy when treating patients with breast cancer. The results of this study will show whether giving tamoxifen citrate, anastrozole, letrozole, or exemestane is more effective when taken with combination chemotherapy. Estrogen can cause the growth of breast cancer cells. Hormone therapy, such as tamoxifen citrate, may fight breast cancer by blocking the use of estrogen by the tumor cells. Drugs such as anastrozole, letrozole, and exemestane may fight breast cancer by lowering the amount of estrogen the body makes. Drugs used in chemotherapy work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from reproducing. The primary objective is to determine the effect of the treatment in invasive disease-free survival (DFS) of women with node-positive breast cancer treated with endocrine therapy with vs without chemotherapy. The study will enroll 9,400 participants from many cancer centers in the US. In addition to other conditions for enrollment, women with a diagnosis of invasive breast cancer, 1 to 3 positive lymph nodes, estrogen receptor; and/or progesterone receptor positive, and HER-2 negative. Eligible patients have had surgery and completed radiotherapy, if it was recommended.