Project Summary

PCORI has identified the need for large studies that look at real-life questions faced by diverse patients, caregivers, and clinicians. To address this need, PCORI launched the Pragmatic Clinical Studies initiative in 2014. Pragmatic clinical studies allow for larger-scale studies with longer timelines to compare the benefits and harms of two or more approaches known to be effective for preventing, diagnosing, treating, or managing a disease or symptom. They focus on everyday care for a wide range of patients. This research project is one of the studies PCORI awarded as part of this program.

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

Breast cancer is the second most common type of cancer diagnosed in women and the second leading cause of cancer death in women. Breast cancer in men is rare, but it does occur.

Patients with breast cancer often undergo surgery to remove part of the breast or the entire affected breast. Radiation therapy after surgery lowers the chance that the cancer will come back. Radiation therapy aims a beam, or many beams, of radiation through the skin to the chest or breast and the surrounding areas to kill cancer cells.

Photon therapy and proton therapy are two types of radiation treatment for cancer. Both treatments give similar doses of radiation to the chest or breast and the surrounding areas. Because some radiation may go to the heart during therapy, patients may have an increased risk of future heart problems. Proton therapy exposes less of the heart to radiation, so this treatment may cause fewer heart problems compared with photon therapy. But not enough patients with breast cancer have received proton therapy to know for sure. Doctors don’t know if one type of radiation is better, about the same, or worse than the other for side effects, cure, length of life, or quality of life after treatment.

Who can this research help?

This research can help people with breast cancer and their doctors decide which type of radiation therapy is right for them.

What is the research team doing?

Researchers at more than 60 treatment sites across the United States are enrolling 1,278 patients with stage 1, 2, or 3 breast cancer who had surgery to remove either part or the entire affected breast. The team is assigning patients by chance to receive either photon therapy or proton therapy. Patients receive treatment five days a week for five to seven weeks.

The research team is following patients for 10 years to track cancer recurrence, heart problems, and quality of life. Heart problems include heart attacks and chest pain. Quality of life includes how patients feel about their bodies, tiredness, their ability to perform tasks daily tasks, side effects, anxiety, stress about money, and satisfaction with treatment.

The research team is involving patients, patient advocates, and other organizations in designing and conducting the study.

Research methods at a glance

Design Elements Description
Design Randomized controlled trial
Population Adults 21 years and older with stage 1, 2 or 3 breast cancer who had surgery to remove part of or the entire affected breast
  • Photon therapy
  • Proton therapy

Primary: major cardiovascular events, such as heart disease, heart attacks, chest pain, and other heart problems

Secondary: recurrence of breast cancer, quality of life, long-term survival

Timeframe 10-year follow-up for primary outcomes

Engagement Resources

More to Explore...


*These videos have been produced and provided by the RadComp Study team.

Project Information

Justin Bekelman, MD
University of Pennsylvania
Pragmatic Randomized Trial of Proton vs. Photon Therapy for Patients with Non-Metastatic Breast Cancer Receiving Comprehensive Nodal Radiation: A Radiotherapy Comparative Effectiveness (RADCOMP) Trial

Key Dates

April 2015
December 2025

Study Registration Information


Award Type
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: September 26, 2023