The STOPHER Trial and HR+/HER2- Early Breast Cancer
I cannot identify any trial called "STOPHER" in the provided evidence or in established breast cancer literature. You may be referring to the STOP-HER2 trial (NCT05721248), which is currently recruiting and investigates discontinuation of first-line HER2-targeted therapy in exceptional responders after at least 3 years of treatment 1.
STOP-HER2 Trial Overview
The STOP-HER2 study is designed for HER2-positive metastatic breast cancer patients, not for HR+/HER2-negative disease 1. This trial addresses a fundamentally different patient population than your clinical scenario.
Key Features of STOP-HER2:
Study Population: Patients with HER2-positive metastatic breast cancer who have achieved exceptional responses to first-line HER2-targeted therapy (pertuzumab and/or trastuzumab) 1
Primary Question: Whether HER2-targeted therapy can be safely discontinued after at least 3 years of treatment in patients with complete or near-complete responses 1
Rationale: Retrospective data showed 5-year overall survival rates of 90.5% and 10-year rates of 87% in 33 patients with HER2-positive metastatic breast cancer who had no evidence of disease after ≥5 years of HER2-targeted therapy 1
Current Status: Actively recruiting as of 2025 1
Why This Trial Is Not Relevant to HR+/HER2- Disease
HR+/HER2-negative breast cancer does not involve HER2-targeted therapy 2. The treatment paradigm for HR+/HER2-negative disease centers on:
- Endocrine therapy as the mainstay of treatment 2
- CDK4/6 inhibitors combined with endocrine therapy for high-risk disease 1, 2
- Chemotherapy based on stage and tumor biology 2
Standard Adjuvant Approach for Postmenopausal HR+/HER2- Early Breast Cancer:
- Aromatase inhibitors for 5-10 years are the preferred endocrine therapy 1, 3
- Extended endocrine therapy beyond 5 years improves outcomes in high-risk patients 1
- CDK4/6 inhibitors may be added for high-risk early disease based on emerging evidence 2
Common Pitfall to Avoid
Do not confuse HER2-positive and HER2-negative disease management - they represent entirely different treatment algorithms with no overlap in targeted therapy approaches 4, 2. HER2-targeted agents (trastuzumab, pertuzumab) have no role in HER2-negative disease 2.
If you intended to ask about a different trial for HR+/HER2-negative early breast cancer, please clarify the trial name, as no "STOPHER" trial exists in the current literature for this population.