How very high HER2 levels affect outcomes after dual HER2 therapy in early breast cancer

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

Observational Shandong Cancer Hospital and Institute · NCT07376174

This project will see if people with very high HER2 levels (HER2/CEP17 ratio >7) do better or worse after getting trastuzumab plus pertuzumab for early-stage HER2-positive breast cancer.

Quick facts

Study typeObservational
Enrollment300 (estimated)
Ages18 Years and up
SexFemale
SponsorShandong Cancer Hospital and Institute Academic / other
Drugs / interventionstrastuzumab, pertuzumab
Locations1 site (Jinan, Shandong)
Trial IDNCT07376174 on ClinicalTrials.gov

What this trial studies

This is an observational cohort analysis of adults with pathologically confirmed stage I–III HER2-positive breast cancer who received at least one dose of dual HER2-targeted therapy (trastuzumab plus pertuzumab) and curative-intent surgery. Patients are grouped by HER2/CEP17 ratio (ultra-high >7 versus typical range) based on FISH testing and their clinicopathological features and outcomes are compared. The primary focus is disease-free survival and recurrence patterns after neoadjuvant or adjuvant dual-target therapy. Cases with distant metastasis at diagnosis, missing key data, prior anti-HER2 therapy before the dual regimen, or concurrent other malignancies are excluded.

Who should consider this trial

Good fit: Adults (≥18) with primary stage I–III HER2-positive breast cancer confirmed by FISH with an available HER2/CEP17 ratio who received trastuzumab plus pertuzumab and underwent curative-intent surgery are the ideal candidates.

Not a fit: Patients with stage IV disease at diagnosis, contralateral or non-primary cancers, missing HER2 FISH data, prior anti-HER2 therapy before the dual regimen, or inadequate follow-up are unlikely to be eligible or benefit from the analysis.

Why it matters

Potential benefit: If successful, the findings could help doctors better predict prognosis and tailor follow-up or treatment intensity for patients with ultra-high HER2 expression.

How similar studies have performed: Prior reports linked ultra-high HER2/CEP17 ratios (>7) to worse disease-free survival with trastuzumab alone, but there is limited clinical evidence on whether adding pertuzumab changes that risk.

Eligibility criteria

Show full inclusion / exclusion criteria
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).

Where this trial is running

Jinan, Shandong

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Breast CancerHER2/CEP17 RatioHER2/CEP17 ratioBreast cancer
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.