Distinct β-Catenin and PIK3CA Mutation Profiles in

Objectives: We focused on the differences in molecular mechanisms in the early stages of endometriosis-associated ovarian endometrioid carcinoma (OEMCa) and ovarian clear cell carcinoma (OCCCa). Methods: Alterations in the β-catenin and PIK3CA genes, as well as expression of their associated markers, were investigated. Results: Mutations in exon 3 of the β-catenin gene were identified in 21 (60%) of 35 OEMCas. The mutations were also detected in the coexisting nonatypical (52.4%) and atypical (73.3%) endometriosis, and the single-nucleotide substitutions were identical in most cases. In contrast, the mutations were not identified in any of the OCCCas and their coexisting endometriosis. PIK3CA mutations were