Different Prognostic Roles of Mutations in the Helical and Kinase Domains of the <i>PIK3CA</i> Gene in Breast Carcinomas

Abstract

Our data show that exon 9 PIK3CA mutations are typical of infiltrating lobular carcinomas. In addition, they indicate that PIK3CA mutations in different exons are of different prognostic value: exon 9 mutations are independently associated with early recurrence and death, whereas exon 20 PIK3CA mutations are associated with optimal prognosis.