Abstract B31: Circulating periostin as a potential biomarker to predict platinum-resistant epithelial ovarian cancer.

Roughly a third of ovarian cancer patients are intrinsically resistant to platinum-based treatment. However, predictive and therapeutic strategies are lacking to treat these patients due to a poor understanding of the underlying molecular mechanisms. We previously identified and validated a “reactive stroma” gene signature that is associated with primary chemoresistance in epithelial ovarian cancers (EOCs). In addition this signature was further validated in an independent dataset and high expression level of the signature genes predicts shorter progression free survival following front line chemotherapy. One of the key components of this gene signature is periostin (POSTN), an extracellular matrix protein known for its role in a variety of tissue remodeling conditions as well as overexpression in many types of cancers. Interestingly, POSTN is also involved in aspects of allergic inflammation and is used as a circulating biomarker for TH2-driven asthma. To investigate whether circulating POSTN could be used to predict chemoresistance in EOC, we developed an ELISA assay for detecting circulating POSTN in serum and plasma. Serum POSTN levels were measured in panels of serum samples from 143 EOC patients, 102 normal healthy subjects (NHS) and from 126 patients with other cancers. The serum POSTN ELISA was sensitive down to 1.88ng/mL and POSTN was detected in the serum of all patients and NHS. Although the range of POSTN expression in the EOC patients was highly overlapping with that of normal healthy subjects, a positive correlation was observed with the stage of disease. Retrospective and prospective studies are underway to determine whether baseline serum-POSTN levels can predict chemoresistance in EOC patients. Our study may lead to the development of a novel diagnostic strategy for predicting response to chemotherapy in ovarian cancer.

Citation Format: Lisa Ryner, Amy Noyes, Denise Nazzal, Paul Vu, Yinghui Guan, Shan Lu, Alyssa Morimoto, Sue Brignoli, Yulei Wang. Circulating periostin as a potential biomarker to predict platinum-resistant epithelial ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B31.