The PIK3CA gene is mutated with high frequency in human breast cancers

Cancer Biol Ther. 2004 Aug;3(8):772-5. doi: 10.4161/cbt.3.8.994. Epub 2004 Aug 26.


The phosphatidylinositol 3-kinases (PI3Ks) are known regulators of cellular growth and proliferation. It has recently been reported that somatic mutations within the PI3K subunit p110alpha (PIK3CA) are present in human colorectal and other cancers. Here we show that thirteen of fifty-three breast cancers (25%) contain somatic mutations in PIK3CA, with the majority of mutations located in the kinase domain. These results demonstrate that PIK3CA is the most mutated oncogene in breast cancer and support a role for PIK3CA in epithelial carcinogenesis.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Biomarkers, Tumor / genetics*
  • Biomarkers, Tumor / metabolism
  • Breast / metabolism
  • Breast Neoplasms / enzymology
  • Breast Neoplasms / genetics*
  • Class I Phosphatidylinositol 3-Kinases
  • Exons / genetics
  • Female
  • Gene Amplification
  • Gene Expression Regulation, Enzymologic*
  • Humans
  • Mutation, Missense*
  • Neoplasm Invasiveness / genetics
  • Neoplasm Invasiveness / pathology
  • Phosphatidylinositol 3-Kinases / genetics*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Tumor Cells, Cultured


  • Biomarkers, Tumor
  • Phosphatidylinositol 3-Kinases
  • Class I Phosphatidylinositol 3-Kinases
  • PIK3CA protein, human