In the context of HER2-positive breast cancer, potential biomarkers or predictive factors that could help identify patients who may not require systemic therapy or could be effectively treated with HER2-targeted therapy alone include:
Tumor Size and Stage: Patients with smaller tumors, particularly stage I HER2-positive breast cancer, may have a lower risk of recurrence and could potentially benefit from HER2-targeted therapy alone without the need for additional systemic treatments.
Response to Neoadjuvant Therapy: Patients who achieve a pathologic complete response (pCR) to neoadjuvant HER2-targeted therapy may have a lower risk of recurrence and could potentially be candidates for treatment de-escalation.
Biomarkers of Treatment Response: Biomarkers such as circulating tumor DNA (ctDNA) or gene expression profiles could help identify patients who have a robust response to HER2-targeted therapy and may not require additional systemic treatments.
Genetic Variants: Specific genetic variants or mutations in HER2-positive breast cancer could influence treatment response and prognosis, guiding the decision on the need for systemic therapy.
Ethnicity and Renal Function: Factors like Asian ancestry and renal dysfunction have been associated with higher rates of certain toxicities, which could impact treatment decisions and the need for systemic therapy.
By incorporating these biomarkers and predictive factors into clinical decision-making, oncologists can better tailor treatment strategies for HER2-positive breast cancer patients, potentially avoiding overtreatment in those who may not benefit from additional systemic therapy.