The Prognostic Impact of HER2 Expression in Non-Metastatic HER2-Positive Breast Cancer Treated With Dual HER2-Targeted Therapy

January 21, 2026 updated by: Fangchao Zheng, MD, Shandong Cancer Hospital and Institute

A Multicenter Retrospective Cohort Study Protocol on the Prognostic Impact of HER2 Expression in Non-Metastatic HER2-Positive Breast Cancer Treated With Dual HER2-Targeted Therapy

Previous studies suggest that among patients receiving trastuzumab monotherapy, a HER2/CEP17 ratio >7.0 (ultra-high expression) is associated with poorer disease-free survival (DFS). Dual-target therapy (trastuzumab + pertuzumab) has become the standard treatment for high-risk HER2-positive breast cancer; however, whether it can predict outcomes in patients with ultra-high HER2 expression remains unsupported by clinical data. To analyze the clinicopathological characteristics and prognostic relationship between the HER2 ultra-high expression group and the normal expression group in non-metastatic HER2-positive breast cancer patients who received dual-target therapy.

Study Overview

Status

Recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

300

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
    • Shandong
      • Jinan, Shandong, China
        • Recruiting
        • Department of Medical Oncology

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

Sampling Method

Non-Probability Sample

Study Population

HER2-positive patients with breast cancer were enrolled between January 2020 and December 2023.

Description

Inclusion Criteria:

  1. Age ≥18 years.
  2. Pathologically confirmed primary breast cancer, clinical stage I-III (AJCC 8th Edition).
  3. HER2-positive status confirmed by FISH testing (per ASCO/CAP guidelines) with available HER2/CEP17 ratio.
  4. Received at least one dose of dual-target therapy (trastuzumab combined with pertuzumab) in the adjuvant or neoadjuvant setting.
  5. Underwent curative-intent surgery (mastectomy or breast-conserving surgery).

Exclusion Criteria:

  1. Presence of distant metastasis (Stage IV) or contralateral breast cancer at initial diagnosis.
  2. Previous anti-HER2 targeted therapy prior to dual-target treatment.
  3. Missing key clinical data (e.g., HER2 FISH results, treatment regimen, surgery date).
  4. Carcinoma in situ or occult breast cancer, non-primary breast cancer, or concurrent other malignancies.
  5. Loss to follow-up or follow-up duration <3 months (unless recurrence or death occurred within this period).

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
HER2 FISH ultra
HER2/CEP17 FISH ratio in HER2-positive non-metastatic breast cancer
HER2 FISH normal
HER2/CEP17 FISH ratio in HER2-positive non-metastatic breast cancer

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Disease-free survival based on HER2/CEP17 ratio
Time Frame: From the date of pathological diagnosis to event with follow-up duration ≥3 months (unless recurrence or death occurred within 3 month).
Defined as the period from the date of pathological diagnosis until the date of the first relapse, appearance of non-breast primary cancer, death with no signs or symptoms of recurrence or metast, or the last recorded follow-up ,whichever came first.
From the date of pathological diagnosis to event with follow-up duration ≥3 months (unless recurrence or death occurred within 3 month).

Collaborators and Investigators

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

Sponsor

Shandong Cancer Hospital and 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 (Actual)

January 10, 2026

Primary Completion (Estimated)

June 10, 2026

Study Completion (Estimated)

June 20, 2026

Study Registration Dates

First Submitted

January 12, 2026

First Submitted That Met QC Criteria

January 21, 2026

First Posted (Actual)

January 29, 2026

Study Record Updates

Last Update Posted (Actual)

January 29, 2026

Last Update Submitted That Met QC Criteria

January 21, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SDTHEC202601024

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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