PIK3CA is the most commonly mutated gene in HR+/HER2- advanced breast cancer1-4
PIK3CA mutations can be detected in tissue or plasma specimens and are generally stable. Primary or metastatic breast cancer tumor tissue may be tested.7-9
The PI3K pathway
Hyperactive signaling in the PI3K pathway has been implicated in processes that contribute to the progression of breast cancer.10
PIK3CA mutations may lead to hyperactivation of PI3Kα, a key upstream component of the PI3K pathway.10-12
How are PIK3CA mutations identified?
A companion diagnostic can be used to identify PIK3CA mutations. PIK3CA mutations are somatic mutations that occur along multiple domains. The companion diagnostic for identifying PIK3CA mutations detects 11 mutations in the PIK3CA gene which are listed in the table below.13
E545D [1635G>T only]
PI3Kα, α-isoform of phosphatidylinositol-3-kinase.
Learn about the first and only therapy in combination with fulvestrant, specifically for postmenopausal women, and men, with HR+/HER2-, PIK3CA-mutated, advanced or metastatic breast cancer following progression on or after an endocrine-based regimen.1