This study is looking at a new way to decide when to start certain breast cancer treatments. If you have early-stage, HR-positive (hormone receptor-positive), HER2-negative breast cancer, you might be able to join. The study uses a blood test called Signatera to look for tiny pieces of cancer DNA (ctDNA). If ctDNA is found, you would start taking a CDK4/6 inhibitor medicine like ribociclib or abemaciclib, along with your usual hormone therapy. If no ctDNA is found, you'll continue hormone therapy and have regular ctDNA tests. The main goal is to see if this ctDNA-guided approach can help you stay cancer-free longer, up to 9 years, compared to past studies.

Study design

This is a single-arm study, meaning all participants receive the same type of intervention, with a planned enrollment of 725 people. It's a Phase II study, which typically focuses on how well a new treatment works and its safety.

What's involved

You would have blood tests every 3 months for up to 4 years to check for ctDNA. You would also receive hormone therapy, and potentially a CDK4/6 inhibitor, with imaging and quality-of-life assessments as needed.

Compensation

Not stated in the trial record.

Follow-up

Participants will be followed for up to 9 years to assess how long they remain free of invasive disease.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.