PIK3CA mutation profiling in Vietnamese patients with breast cancer

Abstract

Activating mutations in phosphoinositide-3-kinase, catalytic, alpha polypeptide (PIK3CA) gene frequently occur in breast cancer, and are important for the survival of patients with breast cancer. Although PIK3CA mutations have been studied widely in many countries, the relationships between PIK3CA mutations and clinicopathological features are still inconsistent. Moreover, information about PIK3CA mutations in Vietnamese breast cancer has not been investigated. In the present study, we identified PIK3CA mutations in 27.2% of 162 human breast tumors, including 31 exon 9 mutations and 13 exon 20 mutations. In addition, PIK3CA mutations were associated with larger tumor size and low Ki67 level. Moreover, the distribution of PIK3CA mutations in the breast cancer subtypes was analyzed. The PIK3CA mutations was not equally distributed among different intrinsic subtypes, in which the rate of mutations in hormone (HR)-positive subtypes was somewhat higher than that in human epidermal growth factor receptor-2 (HER2)-positive subtypes. Overall, this study provides more information about PIK3CA mutations and suggests prognostic and predictive values for breast cancer management in Vietnamese population.