Optimizing Precision Medicine for Breast Cancer Brain Metastases with Functional Drug Response Assessment

Area of Science:

• Oncology
• Translational Research
• Genomics

Background:

• Brain metastases (BM) represent a significant unmet need in cancer therapy.
• Unique molecular features of BM may offer novel therapeutic targets.
• Understanding drug sensitivity and molecular profiles is crucial for prioritizing treatments.

Purpose of the Study:

• To evaluate molecular profiles of breast cancer brain metastases (BCBM) and matched primary tumors.
• To establish patient-derived xenografts (PDX) from BCBM for drug screening.
• To identify potential therapeutic targets and assess drug efficacy in BCBM models.

Main Methods:

• Molecular profiling of 12 BCBM and matched primary tumors.
• Establishment of six novel BCBM-derived PDX models.
• Drug screening of PDX models against a panel of over 350 drugs.
• Analysis of conserved and differential molecular alterations, including PI3K pathway.

Main Results:

• Molecular alterations were largely conserved between BCBM and matched primary tumors.
• Significant differential expression was observed in immune-related and metabolism pathways.
• PI3K pathway alterations were most predictive of drug efficacy in PDX models.
• BCBM PDXs showed high sensitivity to histone deacetylase and proteasome inhibitors.

Conclusions:

• BCBM PDXs effectively capture targetable molecular alterations from the source tumors.
• Functional precision medicine strategies may expand therapeutic options for BCBM.
• Genomic profiling combined with functional evaluation can improve drug development and biomarker assessment for BCBM.