This clinical trial is focused on studying a type of breast cancer known as hormone receptor-positive (HR+) HER2-negative breast cancer in post-menopausal women. The study is specifically looking at women who have a very low risk of the cancer spreading to other parts of the body, known as metastasis. The treatment being studied involves the use of medications called aromatase inhibitors, which include exemestane, letrozole, and anastrozole. These medications are taken orally in the form of tablets.

The purpose of the study is to see if a shorter duration of hormone therapy, specifically two years, is effective in maintaining a high rate of survival without the cancer spreading over a period of five years. Participants in the study will take one of the aromatase inhibitors for up to two years. The study will monitor the participants’ health and any side effects they may experience during this time. The goal is to determine if reducing the length of hormone therapy can still provide effective treatment for this type of breast cancer.

Throughout the study, researchers will track several outcomes, including how long participants remain free from distant metastasis, which means the cancer has not spread to other parts of the body. They will also look at overall survival rates, quality of life, and any adverse effects from the treatment. The results from this study will be compared to those from another study where patients received hormone therapy for five years. This comparison will help determine the safety and effectiveness of the shorter treatment duration.