Detecting actionable PIK3CA mutations through next-generation sequencing (NGS) in hormone receptor positive (HR+)/HER2-negative advanced/metastatic breast cancer (MBC): a real-life experience

Background: PIK3CA mutations occur in approximately 40% of patients (pts) affected by HR+/ HER2-negative MBC, and are associated with poor prognosis. The SOLAR-1 trial showed that pathogenic PIK3CA mutations are theoretically actionable (ESCAT Tier I) through the kinase inhibitor alpelisib. Nevertheless, in Europe and Italy the administration of alpelisib is allowed by regulatory restrictions only in association with fulvestrant, following progression after endocrine therapy (ET) alone.