The top mutated gene was TP53 (63.7%) followed by PIK3CA (24.8%) and others that were mostly co-mutated with TP53 (eg, 22 of 28 PIK3CA mutated tumors were co-mutated in TP53, 17 of these were R-MBC [P = .041]). dn-MBC had higher CEN17 average copies (P = .048).
We developed a targeted 23-amplicon next-generation sequencing (NGS) panel for detection of hot-spot mutations in ESR1, phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA), tumor protein p53 (TP53), fibroblast growth factor receptor 1 (FGFR1), and fibroblast growth factor receptor 2 (FGFR2) in 48 patients with estrogen receptor-α-positive metastatic breast cancer who were receiving systemic therapy.
None of the biomarkers was predictive of treatment response in women with metastatic breast cancer; however, survival differed according to hormone receptor and p53 status.