Correlation between PIK3CA mutations in cell-free DNA and everolimus efficacy in HR⁺, HER2^- advanced breast cancer: results from BOLERO-2.

ABSTRACT:

Background

The current analysis was performed to evaluate the impact of PIK3CA hotspot mutations on everolimus efficacy in BOLERO-2 participants, using cell-free DNA (cfDNA) from plasma samples collected at the time of patient randomisation.

Methods

PIK3CA H1047R, E545K, and E542K mutations in plasma-derived cfDNA were analysed by droplet digital PCR (ddPCR). Median PFS was estimated for patient subgroups defined by PIK3CA mutations in each treatment arm.

Results

Among 550 patients included in cfDNA analysis, median PFS in everolimus vs placebo arms was similar in patients with tumours that had wild-type or mutant PIK3CA (hazard ratio (HR), 0.43 and 0.37, respectively). Everolimus also prolonged median PFS in patients with PIK3CA H1047R (HR, 0.37) and E545K/E542K muta

SUBMITTER: Moynahan ME 

PROVIDER: S-EPMC5355930 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature