Abstract 5706: Gene expression profile of peripheral blood mononuclear cells in breast cancer patients may be contribute to the identification and the immunological classification of breast cancer patients by blood test

Abstract

Abstract It is reported that gene expression profile of peripheral blood mononuclear cells (PBMCs) exhibits unique gene expression signature in cancer patients including renal cell carcinoma, pancreatic cancer and lung cancer. Since pancreatic cancer diagnosis is difficult in not only early detection of the disease but also in the diagnosis itself, development of novel diagnostic tools in addition to conventional diagnostic strategy has been awaited. On the other hand, in breast cancer, because early diagnosis by mammography and ultra sound examination on breast is established successfully, exploration of gene expression profile of PBMCs may be important in terms of insight to host antitumor immune response aspects. In the current study, we performed RNA sequencing (RNA-seq) analysis on RNA of PBMCs from 3 healthy volunteers, 6 early and 7 metastatic breast cancer patients including all phenotypes defined by ER, PgR and HER2. Genes that showed FDR<0.05 and fold change of <0.5 and 2.0< in comparison of healthy volunteers and breast cancer patients were applied to clustering analysis by Ward method. We found significant unique gene expression signature between healthy volunteers and breast cancer patients. Furthermore, it was shown that HER2 overexpressing breast cancer patients, which breast cancer patients were divided into 3 clusters including HER2 type and other 2 different groups, seemed to be classified into healthy group different from other phenotypes of breast cancer patients. These findings suggested that evaluation of gene expression patterns of PBMCs of breast cancer patients might distinguish breast cancer patients from healthy subjects and the gene expression signature of PBMCs which divided breast cancer patients into 3 groups might reveal immunologically important biologic properties such as response prediction of cancer immunotherapy including immune checkpoint inhibition treatment. Citation Format: Eiji Suzuki, Kosuke Kawaguchi, Masahiro Sugimoto, Fengling Pu, Ryuji Uozumi, Ayane Yamaguchi, Mariko Nishie, Moe Tsuda, Takeshi Kotake, Satoshi Morita, Masakazu Toi. Gene expression profile of peripheral blood mononuclear cells in breast cancer patients may be contribute to the identification and the immunological classification of breast cancer patients by blood test [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5706. doi:10.1158/1538-7445.AM2017-5706