Biomarkers
PIK3CA Mutation
Also known as: PI3K mutation, Phosphatidylinositol-4,5-bisphosphate 3-kinase mutation
Definition
A mutation in the PIK3CA gene that activates the PI3K pathway, driving cell growth and survival, found in 30-40% of hormone receptor-positive breast cancers.
Detailed Explanation
PIK3CA mutations are among the most common oncogenic alterations. In breast cancer, they can be targeted with alpelisib (Piqray) in combination with hormone therapy after progression on endocrine therapy. Testing should be done on tumor tissue or liquid biopsy.