PIK3CA alterations in metastatic breast cancer (mBC)

Background null The anticipated approval of the first specific PIK3CA inhibitor, apelisib, has increased interest in the frequency and range of PIK3CA genomic alterations (GA) in the major subtypes of mBC. null null null Methods null DNA was extracted from 3,871 mBC: 1,259 ER+/HER2-, 1,969 HER2 amplified (amp) and 643 TNBC. GA, tumor mutational burden (TMB) and microsatellite instability (MSI) were identified by hybrid-capture. PD-L1 was...