Genomic profiling by circulating tumor DNA in patients with hormone receptor-positive/HER2-negative advanced breast cancer: Prevalence of actionable mutations across treatment lines

Researchers conducted a prospective observational study in Brazil to assess the prevalence of plasma-detected ESR1 mutations before first-line endocrine therapy and after progression on endocrine therapy plus a CDK4/6 inhibitor in patients with HR+ HER2- advanced breast cancer. Next-generation sequencing of 86 plasma samples identified clinically meaningful ESR1 mutation rates across both groups, suggesting that guideline-endorsed plasma-based genomic profiling may be a useful approach in identifying ERS1 mutations in this patient population.