Frequent activating mutations of PIK3CA in ovarian clear cell carcinoma

Am J Pathol. 2009 May;174(5):1597-601. doi: 10.2353/ajpath.2009.081000. Epub 2009 Apr 6.


Ovarian clear cell carcinoma (CCC) is one of the most malignant types of ovarian carcinomas, particularly at advanced stages. Unlike the more common type of ovarian cancer, high-grade serous carcinoma, ovarian CCC is often resistant to platinum-based chemotherapy, and therefore an effective treatment for this tumor type at advanced stages is urgently needed. In this study, we analyzed 97 ovarian CCCs for sequence mutations in KRAS, BRAF, PIK3CA, TP53, PTEN, and CTNNB1 as these mutations frequently occur in other major types of ovarian carcinomas. The samples included 18 CCCs for which affinity-purified tumor cells from fresh specimens were available, 69 microdissected tumors from paraffin tissues, and 10 tumor cell lines. Sequence mutations of PIK3CA, TP53, KRAS, PTEN, CTNNB1, and BRAF occurred in 33%, 15%, 7%, 5%, 3%, and 1% of CCC cases, respectively. Sequence analysis of PIK3CA in 28 affinity-purified CCCs and CCC cell lines showed a mutation frequency of 46%. Samples with PIK3CA mutations showed intense phosphorylated AKT immunoreactivity. These findings demonstrate that ovarian CCCs have a high frequency of activating PIK3CA mutations. We therefore suggest that the use of PIK3CA-targeting drugs may offer a more effective therapeutic approach compared with current chemotherapeutic agents for patients with advanced-stage and recurrent CCC.

Publication types

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

MeSH terms

  • Adenocarcinoma, Clear Cell / genetics*
  • Adenocarcinoma, Clear Cell / metabolism
  • Adenocarcinoma, Clear Cell / pathology
  • Adenocarcinoma, Mucinous / genetics
  • Adenocarcinoma, Mucinous / metabolism
  • Adenocarcinoma, Mucinous / pathology
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism
  • Carcinoma, Endometrioid / genetics
  • Carcinoma, Endometrioid / metabolism
  • Carcinoma, Endometrioid / pathology
  • Class I Phosphatidylinositol 3-Kinases
  • Cystadenocarcinoma, Serous / genetics
  • Cystadenocarcinoma, Serous / metabolism
  • Cystadenocarcinoma, Serous / pathology
  • Female
  • Humans
  • Immunoenzyme Techniques
  • Mutation / genetics*
  • Ovarian Neoplasms / genetics*
  • Ovarian Neoplasms / metabolism
  • Ovarian Neoplasms / pathology
  • Phosphatidylinositol 3-Kinases / genetics*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphorylation
  • Polymorphism, Single Nucleotide / genetics*
  • Prognosis
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction


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