Abstract 3184: Genomic analyses reveal two distinct biologic entities of endometrial endometrioid carcinoma

Proceedings: AACR 107th Annual Meeting 2016; April 16-20, 2016; New Orleans, LA Endometrial carcinoma (EC) is classified into two types: type 1 (endometrioid type) and type 2 (non-endometrioid type). Type 1 endometrioid adenocarcinoma (EA) has been generally considered a single disease entity and was developed from endometrial hyperplasia as a precursor lesion. Recently we identified two distinct subgroups in type 1 EA; groups 1 and 2 as tumors with and without endometrial hyperplasia, respectively. The purpose of this study is to identify genes involved those differentially expressed by groups 1 and 2 EA. Genomic analyses including transcriptome and exome sequencing and immunohistochemistry were performed. For the validation, these data were projected to the TCGA (The Cancer Genome Atlas Research Network) data. In the results of transcriptome, group 1 and 2 EAs identified differential regulation of multiple genes and pathways. As an example, estrogen receptor (ER) related pathways were up-regulated in group 1 EA. Immunohistochemical analyses further confirmed overexpression of ER and PgR in the protein level. In the result of exome sequencing, mutation was observed more frequently in group 2 and sixteen driver genes were more frequently mutated in group 2. Citation Format: Yuko Sugiyama, Nobuyuki Fukui, Osamu Gotoh, Katsuhiko Hasumi, Yutaka Takazawa, Tetsuo Noda, Seiichi Mori. Genomic analyses reveal two distinct biologic entities of endometrial endometrioid carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3184.