Immunotherapy in the neoadjuvant treatment of hormone receptor-positive/HER2-negative early breast cancer: novel approaches and future perspectives

Purpose of review: To summarize recent advances and emerging strategies for integrating immunotherapy into the neoadjuvant treatment of patients with hormone receptor (HR)-positive/HER2-negative early breast cancer (eBC). This review explores how combining immune checkpoint inhibitors (ICIs) with standard treatments and/or novel strategies may potentially improve responses and long-term outcomes. Recent findings: Recent clinical trials have demonstrated that adding ICIs to standard neoadjuvant chemotherapy in HR-positive eBC significantly increases pathological complete response (pCR) rates. However, this benefit should be balanced against an increase in side effects, particularly those immune-mediated. Innovative approaches, such as incorporating radiation therapy to neoadjuvant treatments and ICIs have shown promise in enhancing immune responses, potentially overcoming the lower immunogenicity of luminal-like eBC. Summary: The integration of immunotherapy into neoadjuvant regimens offers a promising strategy to improve outcomes in HR-positive/HER2-negative eBC. While increased pCR rates are encouraging, further research with longer follow-up is necessary to establish the impact on long-term survival. Optimizing patient selection through robust predictive biomarkers and refining combination strategies will be crucial to maximize clinical benefit while minimizing toxicity.