Homologous recombination deficiency in primary ER-positive and HER2-negative breast cancer - PubMed
4 days ago
- #breast cancer
- #homologous recombination deficiency
- #genomic analysis
- Homologous recombination deficiency (HRD) is less frequent in ER-positive/HER2-negative breast cancer (8.4%) compared to triple-negative breast cancer.
- HRD in ER-positive/HER2-negative breast cancer is mainly driven by genetic/epigenetic mechanisms affecting BRCA1/BRCA2/RAD51C/PALB2 genes.
- HRD tumors were found across all PAM50 gene expression subtypes except Luminal A tumors (<1%).
- HRD tumors did not exhibit a unique transcriptional or DNA methylation profile compared to HR-proficient tumors.
- HRD status was not statistically associated with differences in patient outcomes for those treated with combined chemotherapy and endocrine therapy.
- A nonsignificant trend of poorer outcomes was observed for HRD tumors treated with adjuvant endocrine therapy alone.
- HRD tumors show features of aggressive disease but lack distinct molecular profiles differentiating them from HR-proficient tumors.
- HRD stratification by whole genome sequencing (WGS) could impact therapeutic strategies, with HRD tumors trending toward poorer outcomes without chemotherapy.