Neoadjuvant Endocrine Therapy in Breast Cancer: Current Knowledge and Future Perspectives

Area of Science:

• Oncology
• Breast Cancer Research
• Endocrine Therapy

Background:

• Neoadjuvant treatments have significantly advanced HER2-positive and triple-negative breast cancer care.
• The role of neoadjuvant therapy in hormone receptor-positive (HR+), HER2-negative (HER2-) breast cancer (BC) remains debated due to low pathological complete response (pCR) rates.
• Neoadjuvant chemotherapy (NCT) is common, but neoadjuvant endocrine therapy (NET) has untapped potential, particularly for elderly or unfit HR+/HER2- BC patients.

Purpose of the Study:

• To review historical data and recent evidence on neoadjuvant endocrine therapy (NET) for locally advanced (LA) HR+/HER2- breast cancer.
• To discuss the potential of novel agents like CDK4/6 and PI3K/mTOR inhibitors in the neoadjuvant setting.
• To explore key issues including optimal treatment duration, comparison with NCT efficacy, and NET use in premenopausal patients.

Main Methods:

• Historical data review of Tamoxifen and Aromatase Inhibitors in neoadjuvant settings.
• Discussion of recent clinical evidence for novel targeted agents (CDK4/6, PI3K/mTOR inhibitors).
• Analysis of critical treatment parameters such as duration and patient population (premenopausal).

Main Results:

• While NCT is standard, NET's potential in LA HR+/HER2- BC is under-explored.
• Emerging targeted therapies are being investigated within NET platforms.
• Optimal NET strategies, including length and applicability to diverse patient groups, require further elucidation.

Conclusions:

• Neoadjuvant endocrine therapy (NET) offers a promising avenue for managing locally advanced hormone receptor-positive, HER2-negative breast cancer, especially in specific patient populations.
• NET serves as a crucial platform for evaluating novel therapeutics and predictive biomarkers.
• Further research is essential to define optimal NET protocols and its comparative efficacy against neoadjuvant chemotherapy.