Radiation Therapy and Thymus Function in Young Women With Breast Cancer

July 21, 2026 updated by: Duke University

Off-Target Effects of Breast Cancer Adjuvant Radiation Therapy on Thymus Function in Young Women

Breast cancer treatment sometimes includes radiation to the breast or chest wall. There is a small gland, called the thymus, located in the upper chest that may receive a small amount of the radiation aimed at the breast. The goal of this study is to collect blood samples from young women with breast cancer to study the effect of radiation therapy on the thymus gland.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This study includes participants whose plan of care may or may not include radiation therapy.

  • Participants whose plan of care includes radiation therapy will have about three teaspoons of research blood collected at the following time points:

    • Before the start of radiation therapy
    • At the end of radiation therapy
    • About six months after completing radiation therapy

  • Participants whose plan of care does NOT include radiation therapy will have about three teaspoons of research blood collected at the following timepoints:

    • After surgery (up to three months after surgery)
    • About 8 months after the first research blood collection

Study Type

Observational

Enrollment (Estimated)

125

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • North Carolina
      • Durham, North Carolina, United States, 27710
        • Duke Cancer Center
        • Contact:
        • Contact:
        • Principal Investigator:
          • Susan McDuff, MD PhD
        • Principal Investigator:
          • Andrew Macintyre, PhD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

The study population includes women age 18-50 with breast cancer seen in the Duke Breast Oncology Program

Description

Inclusion Criteria:

  • Women aged 18 to 50 undergoing mastectomy or breast-conserving surgery for breast cancer of any subtype at DUMC and associated satellite centers
  • Histologic documentation of breast cancer based on pathology
  • Systemic therapies including hormone therapy, targeted therapy, chemotherapy and immunotherapy as given for breast cancer treatment at the discretion of the treating medical oncologist are allowed and use of such therapies will be documented and included as a covariate
  • Willing and able to provide written informed consent

Exclusion Criteria:

  • Prior history of therapeutic high-dose irradiation of the thorax (e.g. for treatment of lung cancer, head/neck cancer, Hodgkin disease, etc., not just radiological imaging alone)
  • History of thymectomy or treatment with immunosuppressive drugs within the past six months
  • Individuals with rheumatoid arthritis or other autoimmune conditions
  • Individuals with Down's syndrome
  • Male patients

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Radiation Therapy
Up to 100 Breast cancer patients receiving radiation therapy
Procedure: Blood draw for the laboratory assessment
Blood will be drawn and processed for Peripheral Blood Mononuclear Cells (PBMCs). PBMC biomarkers will be used to assess thymopoiesis .
No Radiation Therapy
Up to 25 Breast cancer patients NOT receiving radiation therapy as control
Procedure: Blood draw for the laboratory assessment
Blood will be drawn and processed for Peripheral Blood Mononuclear Cells (PBMCs). PBMC biomarkers will be used to assess thymopoiesis .

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Level of signal joint T cell Receptor Exclusion Circles (sjTREC) in peripheral blood T cells
Time Frame: baseline
As measured by quantitative PCR in participants receiving radiotherapy (RT)
baseline
Level of signal joint T cell Receptor Exclusion Circles (sjTREC) in peripheral blood T cells
Time Frame: at the end of RT, about 5 weeks
As measured by quantitative PCR in participants receiving radiotherapy (RT)
at the end of RT, about 5 weeks
Level of signal joint T cell Receptor Exclusion Circles (sjTREC) in peripheral blood T cells
Time Frame: 6 months post-RT
As measured by quantitative PCR in participants receiving radiotherapy (RT)
6 months post-RT
Level of signal joint T cell Receptor Exclusion Circles (sjTREC) in peripheral blood T cells
Time Frame: within 3 months after breast cancer surgery
As measured by quantitative PCR in participants NOT receiving radiotherapy (RT)
within 3 months after breast cancer surgery
Level of signal joint T cell Receptor Exclusion Circles (sjTREC) in peripheral blood T cells
Time Frame: approximately 8-11 months after breast cancer surgery
As measured by quantitative PCR in participants NOT receiving radiotherapy (RT)
approximately 8-11 months after breast cancer surgery
Level of CD4+ recent thymic emigrant (RTE) cells in participant blood samples
Time Frame: baseline
As measured by flow cytometry in blood from participants receiving radiotherapy (RT)
baseline
Level of CD4+ RTE cells in participant blood samples
Time Frame: at the end of RT, about 5 weeks
As measured by flow cytometry in blood from participants receiving radiotherapy (RT)
at the end of RT, about 5 weeks
Level of CD4+ RTE cells in participant blood samples
Time Frame: 6 months post RT
As measured by flow cytometry in blood from participants receiving radiotherapy (RT)
6 months post RT
Level of CD4+ RTE cells in participant blood samples
Time Frame: within 3 months of breast cancer surgery
As measured by flow cytometry in blood from participants NOT receiving radiotherapy (RT)
within 3 months of breast cancer surgery
Level of CD4+ RTE cells in participant blood samples
Time Frame: approximately 8-11 months after breast cancer surgery
As measured by flow cytometry in blood from participants NOT receiving radiotherapy (RT)
approximately 8-11 months after breast cancer surgery
Effect of adjuvant radiotherapy treatment dose on levels of sjTREC-containing T cells
Time Frame: 6 months post RT
using a linear mixed-effect model in participants receiving RT
6 months post RT
Effect of adjuvant radiotherapy treatment fractionation on levels of sjTREC-containing T cells
Time Frame: 6 months post RT
using a linear mixed-effect model in participants receiving RT
6 months post RT
Effect of adjuvant radiotherapy treatment fractionation on levels of CD4+ RTE cells
Time Frame: 6 months post RT
using a linear mixed-effect model in participants receiving RT
6 months post RT
Effect of adjuvant radiotherapy treatment dose on levels of CD4+ RTE cells
Time Frame: 6 months post RT
using a linear mixed-effect model in participants receiving RT
6 months post RT

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Duke University

Investigators

  • Principal Investigator: Susan McDuff, MD PhD, Duke University Health System (DUHS)
  • Principal Investigator: Andrew Macintyre, PhD, Duke Human Vaccine Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

September 1, 2026

Primary Completion (Estimated)

September 1, 2029

Study Completion (Estimated)

September 1, 2029

Study Registration Dates

First Submitted

July 21, 2026

First Submitted That Met QC Criteria

July 21, 2026

First Posted (Actual)

July 24, 2026

Study Record Updates

Last Update Posted (Actual)

July 24, 2026

Last Update Submitted That Met QC Criteria

July 21, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • Pro00120784
  • BC250719P1 (Other Grant/Funding Number: Department of Defense (DoD))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

IPD may be shared after publication if deidentified.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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