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

Shandong First Medical University

Status: Enrolling

Conditions: Breast Cancer; HER2/CEP17 Ratio

Study type: Observational

Funder types: Other

Identifiers

NCT07376174

SDTHEC202601024

Details and patient eligibility

About

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.

Enrollment: 300 estimated patients

Sex: Female

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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).

Trial design

300 participants in 2 patient groups

HER2 FISH ultra

Description:

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

HER2 FISH normal

Description:

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