Use of Liquid Biopsy to Detect PIK3CA Mutation in Metastatic Breast Cancer.

Background: PIK3CA is associated with tumor progression, and the prevalence of PIK3CA mutation is high in breast cancer. Liquid biopsy offers convenient, noninvasive, and real-time insight into genetic alteration. In this study, we used liquid biopsy to detect PIK3CA mutations in patients with breast cancer.