Risk-Stratified Hypofractionated Radiotherapy After Breast-Conserving Surgery for Early Breast Cancer

June 14, 2026 updated by: Cancer Institute and Hospital, Chinese Academy of Medical Sciences

A Prospective Study of Risk-Stratified Hypofractionated Radiotherapy After Breast-Conserving Surgery for Early Breast Cancer

This prospective study is designed to evaluate the feasibility, efficacy, and safety of risk-stratified hypofractionated radiotherapy after breast-conserving surgery in patients with early breast cancer.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Eligible patients with early breast cancer who have undergone breast-conserving surgery will be stratified into a high-risk group or a low-risk group according to the presence or absence of predefined high-risk factors.

Patients in the high-risk group will receive whole-breast irradiation with a simultaneous integrated boost to the tumor bed. The prescribed dose will be 36 Gy in 15 fractions over 3 weeks to the whole breast and 48 Gy in 15 fractions over 3 weeks to the tumor bed.

Patients in the low-risk group will receive partial-breast irradiation. Two hypofractionated schedules may be used: 40.05 Gy in 15 fractions over 3 weeks or 26 Gy in 5 fractions over 1 week.

Patients will be followed during and after radiotherapy to evaluate treatment efficacy, recurrence rates, and acute and late radiation-related toxicities.

Study Type

Interventional

Enrollment (Estimated)

649

Phase

  • Not Applicable

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

  • China
    • Beijing Municipality
      • Beijing, Beijing Municipality, China, 100021
        • Cancer Hospital, Chinese Academy of Medical Sciences
        • Contact:

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
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • ECOG performance status score of 0 to 2.
  • Pathologically confirmed breast cancer, including invasive carcinoma or ductal carcinoma in situ.
  • Clinical stage cT0-2N0M0.
  • Underwent breast-conserving surgery.
  • Negative surgical margins greater than 2 mm.

Exclusion Criteria:

  • Regional lymph node metastasis.
  • Distant metastasis.
  • Bilateral breast cancer.
  • Prior thoracic radiotherapy.
  • Life expectancy of less than 5 years.
  • Lactating or pregnant women.

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

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Factorial Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Arm 1: High-risk group

Patients who undergo upfront breast-conserving surgery will be assigned to the high-risk group if any of the following high-risk factors are present:

  • Age younger than 40 years.

    • Histology of invasive lobular carcinoma or micropapillary carcinoma.

      • Multifocal disease, defined as two or more breast tumor foci.

        • Tumor size greater than 3 cm.

          • Lymphovascular invasion.

            • Invasive carcinoma with an extensive intraductal component.

              • Estrogen receptor-negative disease.

Patients who receive neoadjuvant chemotherapy followed by breast-conserving surgery will be assigned to the high-risk group if any of the following high-risk factors are present:

  • Age younger than 40 years.

    • Histology of invasive lobular carcinoma or micropapillary carcinoma.

      • Multifocal breast tumor before treatment.

        • Lymphovascular invasion.

          • Pathologic stage ypT1-2N0.
Radiation: Whole-breast irradiation and tumor bed boost
Whole-breast irradiation: 36 Gy in 15 fractions; Tumor bed boost: 48 Gy in 15 fractions
Active Comparator: Arm 2: Low-risk group

Patients who undergo upfront breast-conserving surgery will be assigned to the low-risk group if they meet either of the following criteria:

① Ductal carcinoma in situ (DCIS): age 40 years or older, unifocal disease on breast MRI, tumor size 3 cm or smaller, estrogen receptor-positive disease, and low-, intermediate-, or high-grade disease.

② Invasive carcinoma, including invasive ductal carcinoma, mucinous carcinoma, papillary carcinoma, or tubular carcinoma: age 40 years or older, unifocal disease on breast MRI, tumor size 3 cm or smaller, grade 1 to 3 disease, no lymphovascular invasion, and estrogen receptor-positive disease.

Patients who receive neoadjuvant chemotherapy followed by breast-conserving surgery will be assigned to the low-risk group if all of the following criteria are met: Age 40 years or older, unifocal disease on pretreatment breast MRI, pretreatment core needle biopsy showing invasive ductal carcinoma, and pathologic stage ypT0/isN0.
Radiation: Partial-breast irradiation
Partial-breast irradiation: 40.05 Gy in 15 fractions or 26 Gy in 5 fractions

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Local recurrence rate
Time Frame: Five years
Ipsilateral breast recurrence rate
Five years

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Disease-free survival rate
Time Frame: Five years
Disease-free survival rate
Five years
Radiation-related adverse events
Time Frame: Five years
Adverse events
Five years

Collaborators and Investigators

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

Sponsor

Cancer Institute and Hospital, Chinese Academy of Medical Sciences

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)

June 15, 2026

Primary Completion (Estimated)

December 31, 2027

Study Completion (Estimated)

December 31, 2032

Study Registration Dates

First Submitted

June 14, 2026

First Submitted That Met QC Criteria

June 14, 2026

First Posted (Actual)

June 18, 2026

Study Record Updates

Last Update Posted (Actual)

June 18, 2026

Last Update Submitted That Met QC Criteria

June 14, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NCC25/095-0095

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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