A Real-World Study on the Impact of Different Adjuvant Treatment Regimens on Prognosis in Non-pCR Patients With HER2-Positive Breast Cancer After Neoadjuvant Therapy

April 14, 2026 updated by: Tao Zhou, Hebei Medical University Fourth Hospital

Retrospective Real-World Cohort Study on the Impact of Different Adjuvant Treatment Regimens on Prognosis in Non-pCR Patients With HER2-Positive Breast Cancer After Neoadjuvant Therapy

This study is a multicenter, retrospective, real-world cohort study. It retrospectively collected data from HER2-positive breast cancer patients who received neoadjuvant therapy with trastuzumab-containing chemotherapy regimens and had Non-pCR after surgery between July 2019 and July 2025. Patients were divided into two groups based on their adjuvant treatment regimens: the trastuzumab combined with pertuzumab group (HP) and the ado-trastuzumab emtansine group (T-DM1). The planned sample size is 2000 cases.

Study Overview

Status

Not yet recruiting

Conditions

Study Type

Observational

Enrollment (Estimated)

2000

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

Probability Sample

Study Population

The planned total number of cases is 2000.

Description

Inclusion Criteria:

  • Histopathologically confirmed HER2-positive breast cancer (i.e., immunohistochemistry (IHC) staining result of 3+, or HER-2 2+ with fluorescence in situ hybridization showing HER-2 gene amplification);
  • Received neoadjuvant therapy with chemotherapy combined with trastuzumab before surgery: including at least 6 cycles of chemotherapy, with at least 4 cycles of taxane-based chemotherapy; and at least 4 cycles of trastuzumab treatment (including trastuzumab biosimilars and subcutaneous formulations);
  • Completion of radical surgery, postoperative pathology confirms the presence of invasive carcinoma in the breast and/or axillary lymph nodes after neoadjuvant therapy.
  • Hormone receptor status is known.

Exclusion Criteria:

  • Combine other systemic malignant tumors, excluding cured basal cell carcinoma of the skin and cervical carcinoma in situ;
  • Stage IV metastatic breast cancer;
  • Incomplete clinical pathology and follow-up data; Study endpoints

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
HP
The trastuzumab combined with pertuzumab group
T-DM1
The ado-trastuzumab emtansine group

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Three-year invasive disease-free survival (iDFS) rate for non-pCR patients
Time Frame: From date of enrollment until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 3 years.
iDFS events include local and regional recurrence, distant metastasis, contralateral invasive breast cancer, second non-breast primary cancer (excluding non-invasive carcinoma in situ), and death from any cause at 3 years.
From date of enrollment until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 3 years.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
3-year iDFS rate in Near-pCR patients:
Time Frame: From date of enrollment until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 3 years.
3-year iDFS rate in Near-pCR patients: iDFS events include local and regional recurrence, distant metastasis, contralateral invasive breast cancer, second non-breast primary cancer (excluding non-invasive carcinoma in situ), and death from any cause at 3 years in Near-pCR patients (Near-pCR is defined as Miller & Payne grade 4, MP5 with invasive cancer present in axillary lymph nodes, RCB1).
From date of enrollment until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 3 years.
Overall survival
Time Frame: It is a direct measure of the treatment's ultimate impact on patient survival.
Overall Survival (OS) refers to the length of time from either the date of diagnosis or the start of treatment for a disease (such as cancer) until death from any cause.
It is a direct measure of the treatment's ultimate impact on patient survival.
Adverse Events
Time Frame: From date of enrollment until adjuvant therapy after surgery 1 year
Safety refers to the assessment of adverse events (AEs) and potential risks associated with a medical intervention (e.g., drug, device, procedure)
From date of enrollment until adjuvant therapy after surgery 1 year

Collaborators and Investigators

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

Sponsor

Hebei Medical University Fourth Hospital

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)

August 2, 2026

Primary Completion (Estimated)

August 31, 2026

Study Completion (Estimated)

December 31, 2026

Study Registration Dates

First Submitted

January 19, 2026

First Submitted That Met QC Criteria

April 14, 2026

First Posted (Actual)

April 20, 2026

Study Record Updates

Last Update Posted (Actual)

April 20, 2026

Last Update Submitted That Met QC Criteria

April 14, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • RWS

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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