Study Overview: This study tests a new drug called camizestrant in people with a specific type of early breast cancer. This cancer type is ER+/HER2-, which means it grows with certain hormones but not with a protein called HER2. The study checks if camizestrant works better than the usual hormone treatments that patients have already been on for 2 to 5 years. The study lasts for 5 years, with follow-ups for 10 years to see how well patients do.

Key Points:

• The study lasts for 60 months, with a follow-up period of up to 10 years.
• Participants should have already completed 2-5 years of standard hormone therapy.
• Prior use of CDK4/6 inhibitors is allowed, which are drugs that help stop cancer cells from growing.

Eligibility: To join, you must be 18 or older, have a certain type of early-stage breast cancer, and have finished surgery and possibly chemo. You can't join if your cancer has spread too much or if you have serious health issues. Pregnant or breastfeeding people, and those with allergies to the study drugs, cannot participate. This research aims to see if camizestrant can help patients live longer without the cancer returning.