Background: Ovarian clear cell carcinoma (OCCC) is a distinct histopathological subtype in epithelial ovarian cancer, and its pathological features and gene expression profiles are similar to those of clear cell renal cell carcinoma (ccRCC), including HIF pathway activation. Methods: We performed whole exome sequencing and/or SNP typing array in 45 OCCC clinical samples, and obtained the data of ccRCC from TCGA. Results: We identified several genetic mutations in SWI/SNF complex and PI3K/mTOR pathway, which had been reported in ccRCC, but not in OCCC. Mutations of ARID1A (BAF250a) were predominant in OCCC (55% vs 4%), whereas PBRM1 (BAF180) mutations were detected only in ccRCC at 35%. Mutations of PIK3CA (60% vs 3.0%) and the genetic alterations in the PI3K/mTOR pathway (65% vs 30%, p<0.05 by Fisher's exact test) were more common in OCCC. Distinct from ccRCC, we did not detect any mutations in VHL and copy number losses at chr 3p in OCCC. Conclusions: Genetic alteration patterns in the SWI/SNF complex and the PI3K/mTOR pathway are distinct between OCCC and ccRCC. Our data suggest that targeting mTOR pathway might be a promising therapeutic strategy in OCCC, as well as in ccRCC.

Citation Format: Kayo Asada, Takahiro Koso, Katsutoshi Oda, Yuriko Uehara, Shogo Yamamoto, Kenji Tatsuno, Hiroki Ueda, Reiko Kurikawa, Yuji Ikeda, Osamu Hiraike, Kei Kawana, Tetsu Yano, Yutaka Osuga, Tomoyuki Fujii, Hiroyuki Aburatani. Comparison of genomic alteration patterns between ovarian clear cell carcinoma and renal cell carcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: From Concept to Clinic; Sep 18-21, 2013; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2013;19(19 Suppl):Abstract nr A19.