Radiation therapy with or without calorie reduction for early breast cancer

Plain-English translation of NCT04959474 on ClinicalTrials.gov ↗ · Source last updated January 2026 · Translation generated August 2026 · How we translate trials

This study doesn't follow the usual testing phases — it may be an observational study or a different type of research.

What is this trial?

This trial is testing whether reducing calorie intake during radiation therapy helps shrink breast cancer tumors more effectively in people with early-stage disease. Half of participants will receive the radiation therapy alone, while the other half will also follow a calorie-restricted diet (eating about 25% fewer calories) during their radiation treatment. Both groups will then have surgery to remove the remaining cancer.

Researchers want to know if diet can help radiation therapy work better against breast cancer. By studying how calorie restriction affects tumor response, they hope to develop more effective combination treatments that could improve outcomes for patients before surgery.

Do you qualify?

You likely qualify if…

you have been diagnosed with ductal carcinoma in situ (DCIS) or invasive breast cancer
your tumor is 3 centimeters or smaller
you are at least 40 years old (or 50 if you have triple negative breast cancer)
you have a body mass index of 21 or higher
you are willing to follow either a standard or calorie-restricted diet for 6–12 weeks

You likely don't qualify if…

you have cancer that has spread to your lymph nodes or other parts of your body (with limited exceptions)
you have already received radiation therapy on the same breast
you have already had chemotherapy for this cancer diagnosis
you have significant psychiatric illness that would make it hard to stick to the study plan
you have cancer spreading to your nipple (Paget's disease)

What participation looks like

If you join this trial, you will be randomly assigned to one of two groups. One group will receive standard dietary advice, while the other will reduce their calories by about 25% for 6–12 weeks. Both groups will receive radiation therapy five times over about two weeks (every other day), followed by surgery 4–12 weeks later to remove the remaining cancer. Your doctors will monitor your tumor response using imaging and blood tests, and will assess how well you heal after surgery.

AI-generated summary from trial data · Aug 11, 2026 · Not medical advice

Radiation therapy with or without calorie reduction for early breast cancer

What is this trial?

Do you qualify?

What participation looks like

Trial locations