Conformal Ablative Radiotherapy in Older Women (CARMEN) With Breast Cancer Undergoing Non-Operative Management (CARMEN)

This phase II study evaluates SABR as non-operative treatment for women aged 65+ with ER-positive, HER2-negative breast cancer ≤5 cm and no lymph node involvement. Eligible patients, including those previously on endocrine therapy, receive 5 SABR treatments, followed by monitoring of quality of life and assessment of treatment-related toxicity.

Study Overview

• Status: Recruiting
• Conditions: Breast Cancer Female
• Intervention / Treatment: Radiation: SABR

Detailed Description

This is a prospective, phase II study of women with localized breast cancer receiving non-operative management with SABR delivered to the primary tumor. Patients will be screened that are age 65 and over with invasive breast cancer. Those eligible for the trial will have ER-positive and HER2-negative disease measuring ≤5 cm with negative clinical lymph nodes. Patients that were previously on primary ET, with either stable or progressive disease, will be eligible for this study if other inclusion criteria are met. Participants will receive SABR targeting the tumor consisting of 5 total treatments. Participants will then follow-up as per protocol with quality-of-life assessments and treatment-related toxicity evaluation.

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Amanda Project Manager; Phone Number: 913-588-1617; Email: aschroeder3@kumc.edu
• Study Contact Backup: Name: Rachel Clinical Research Coordinator; Phone Number: 913-945-6955; Email: rheueisen@kumc.edu

Study Locations

• United States
  • Kansas
    • Kansas City, Kansas, United States, 66160
      • Recruiting
      • University of Kansas Medical Center
      • Contact: Rachel Clinical Research Coordinator; Phone Number: 913-588-6249; Email: rheueisen@kumc.edu
    • Kansas City, Kansas, United States, 66160
      • Not yet recruiting
      • University of Kansas Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Willing and able to provide written informed consent obtained to participate in the study and HIPAA authorization for release of personal health information.
• Women greater than or equal to age 65 years
• Diagnosis of invasive carcinoma of breast undergoing non-operative management
• Previously untreated OR previously treated with primary ET or chemotherapy, with either stable or progressive localized disease.
• Tumor measuring ≤5 cm (cT1-T2) and clinically node negative
• Diagnostic biopsy ER-positive (greater than or equal to 10% ER by immunohistochemistry staining)
• Diagnostic biopsy HER2-negative according to ASCO/CAP guidelines (0 or 1+ following IHC staining or proven negative by in-situ hybridization)
• Suitable for SABR as deemed by the treating radiation oncologist
• Participants with a prior or concurrent malignancy whose natural history or treatment does not have the potential to interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial
• Enrollment in another clinical trial is allowed if there would be no interference with interventions on this trial

Exclusion Criteria:

• Active treatment with systemic chemotherapy for breast cancer. Subjects will need to stop any breast cancer chemotherapy agent before enrollment to be included study.
• Multicentric tumor.
• Clinical or imaging evidence of distant metastases.
• Prior ipsilateral breast or thoracic radiation.
• Autoimmune conditions with associated radiation risks.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: SABR Intervention Without Surgery (Single Arm Only); Radiotherapy will be conducted in 5 fractions, every other day. The radiation dose used in this study will use a standard of care post-operative dose of 600 cGy per fraction at 5 total fractions delivered to the clinical target volume. However, since patients in this study will have gross disease and will not have received surgery, a higher dose will be given to the primary tumor itself. Study participants may not receive chemotherapeutic agents after enrollment, unless indicated for disease progression. Patients will be allowed to receive CKD 4/6 inhibitors. Patients will be allowed on this study whether they do or do not receive anti-hormonal therapy. If a patient has not started endocrine therapy before SABR, ideally, they would initiate endocrine therapy after undergoing SABR. If a patient has already started endocrine therapy before SABR, they may continue during the time of SABR at the discretion of the treating physician, as this is considered safe in this setting.

Radiation: SABR; Radiation therapy will consist of either IMRT or 3D CRT. The modality chosen will be based on the plan with the preferable dosimetric variables and determined by the treating radiation oncology physician. SABR will be prescribed to a total dose of 35 Gy to the GTV over the course of 5 fractions (7 Gy per fraction), ideally treated every other day (excluding weekends). The CTV will be prescribed 30 Gy over 5 fractions, ideally treated every other day.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
1-month post-SABR Physical Well-Being	To estimate the change in the score from baseline to 1-month post-SABR on the BREAST-Q: Physical Well-Being Chest Module in older women receiving non-operative management with SABR for localized breast cancer. Conversion Table will be used to convert the raw scale summed score into a score from 0 (worst) to 100 (best). Higher scores reflect a better outcome.	1 month

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient Reported Outcome	To estimate the change in the score from baseline to 1-month, 6-, and 12-months post-SABR in older women with localized breast cancer undergoing non-operative management using the following BREAST-Q Modules: Satisfaction With Breasts, Adverse Effects of Radiation, Cancer Worry, and Physical-Well Being Chest. Conversion Table will be used to convert the raw scale summed score into a score from 0 (worst) to 100 (best). Higher scores reflect a better outcome.	12 months
Treatment Perception	To capture patient perception about treatment with SABR using the three-item survey "Was it worth it?" (WIWI). Scores will be summed from 3 (lowest) to 9 (highest). Higher scores reflect higher satisfaction.	12 months
Incidence of SABR-Related Adverse Events [Safety and Tolerability]	To describe treatment-related toxicity at 1-month, 6-, and 12-months post-SABR using Common Terminology Criteria for Adverse Events (CTCAE) in older women with localized breast cancer undergoing non-operative management.	12 months
Estimation of Short-term Survival Outcomes	To estimate 1-year progression-free survival (PFS) and overall survival (OS) amongst older women undergoing non-operative management after receiving SABR. Units of Measure include 'alive with disease', 'alive without disease', 'deceased with disease', and 'deceased without disease' at 1-year time interval.	1 year

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Exploratory Objective-Estimation of Long-term Survival Outcomes	To estimate 2-year and 5-year PFS and OS amongst older women undergoing non-operative management after receiving SABR. Units of Measure include qualitative analysis at 2-years and 5-years post-radiation: 'alive with disease', 'alive without disease', 'deceased with disease', and 'deceased without disease'.	2- and 5-years

Collaborators and Investigators

• Sponsor: University of Kansas Medical Center
• Investigators: Principal Investigator: Morse, MD, University of Kansas Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): November 4, 2025
• Primary Completion (Estimated): September 1, 2027
• Study Completion (Estimated): October 1, 2027

Study Registration Dates

• First Submitted: November 13, 2025
• First Submitted That Met QC Criteria: November 19, 2025
• First Posted (Actual): November 21, 2025

Study Record Updates

• Last Update Posted (Actual): February 10, 2026
• Last Update Submitted That Met QC Criteria: February 6, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Geriatric; HER2-negative; ER-positive
• Other Study ID Numbers: IIT-2025-CARMEN

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes