Prospective Cohort for Tumor Bed Boost Radiotherapy in HER2 Positive Breast Cancer (BOOST-HER2)

August 6, 2026 updated by: Haeyoung Kim, Samsung Medical Center

The purpose of this study is to analyze treatment outcomes related to tumor bed boost of postoperative radiation therapy in patient with HER2+ breast cancer who underwent breast conserving surgery.

The main questions it aims to answer are:

7-year ipsilateral breast tumor recurrence
7-year disease-free survival
7-year locoregional recurrence
7-year overall survival
Adverse events of radiation therapy

Participants will be assessed by multi-dimensional methods after radiation therapy:

Assessment for the disease status (disease-free or recurrence) including physical and radiologic examination
Assessment for the adverse events according to CTCAE version 5.0

Study Overview

Status

Recruiting

Conditions

Breast Cancer

Intervention / Treatment

Radiation: Whole breast irradiation +/- tumor bed boost

Study Type

Observational

Enrollment (Estimated)

400

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

Name: Haeyoung Kim, MD, PhD
Phone Number: 82-2-3410-2612
Email: haeyoung0131.kim@samsung.com

Study Locations

South Korea
- Seoul
  - Seoul, Seoul, South Korea, 06351
    - Recruiting
    - Samsung Medical Center
    - Contact:
      
      Haeyoung Kim, MD, PhD
      
      Phone Number: 82-2-3410-2612
      
      Email: haeyoung0131.kim@samsung.com

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

Sampling Method

Non-Probability Sample

Study Population

Any HER2+ invasive breast cancer patient with eligible performance except previous history of radiation therapy to ipsilateral breast

Description

Inclusion Criteria:

Female patients with age minimum 19
Pathological confirmation of HER2+ invasive breast cancer
Eastern Cooperative Oncology Group performance status 0-2
Informed consent of the participant

Exclusion Criteria:

Pathological confirmation of ductal carcinoma in situ of the breast
Previous history of radiation therapy to ipsilateral breast

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ipsilateral breast tumor recurrence Time Frame: 7 years from the start of the postoperative radiation therapy	The event for ipsilateral breast tumor recurrence (IBTR) was defined as any breast tumor recurrence in irradiated breast.	7 years from the start of the postoperative radiation therapy

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Disease-free survival Time Frame: 7 years from the start of the postoperative radiation therapy	The event for disease-free survival (DFS) was defined as any local, regional, or distant recurrence or breast cancer-related death.	7 years from the start of the postoperative radiation therapy
Locoregional recurrence Time Frame: 7 years from the start of the postoperative radiation therapy	The event for locoregional recurrence was defined as recurrence in irradiated breast / chest wall or regional lymph node area.	7 years from the start of the postoperative radiation therapy
Overall survival Time Frame: 7 years from the start of the postoperative radiation therapy	The event for overall survival (OS) was defined as death of any cause.	7 years from the start of the postoperative radiation therapy
Adverse events Time Frame: 7 years from the start of the postoperative radiation therapy	Adverse events were evaluated and graded according to CTCAE version 5.0.	7 years from the start of the postoperative radiation therapy

Collaborators and Investigators

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

Sponsor

Samsung Medical Center

Investigators

Principal Investigator: Haeyoung Kim, MD, PhD, Samsung Medical Center

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 (Actual)

November 29, 2022

Primary Completion (Estimated)

November 29, 2030

Study Completion (Estimated)

November 29, 2032

Study Registration Dates

First Submitted

May 30, 2023

First Submitted That Met QC Criteria