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

N/ANot Yet RecruitingNCT07540520

Hebei Medical University Fourth Hospital2,000 enrolled

Overview

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 Type

OBSERVATIONAL

Enrollment

2,000

Conditions

Early Breast Cancer

Eligibility

Sex: FEMALEMin age: 18 Years

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Three-year invasive disease-free survival (iDFS) rate for non-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.

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.

Secondary Outcomes

3-year iDFS rate in Near-pCR patients:

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).

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.

Overall 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.

Time frame: It is a direct measure of the treatment's ultimate impact on patient survival.

Adverse Events

Safety refers to the assessment of adverse events (AEs) and potential risks associated with a medical intervention (e.g., drug, device, procedure)

Time frame: From date of enrollment until adjuvant therapy after surgery 1 year