ROR2 Expression in Breast Cancer
Xiangqian Guo, Patrick Sweeny, Sushama Varma, Kelli Montgomery, Robert B West, Matt van de Rijn. Stanford University School of Medicine, Stanford, CA
Background: ROR2 is an orphan receptor tyrosine kinase that is expressed by several cancer types. ROR2 mediates the WNT signaling pathway and is involved in tumor invasion in sarcomas and renal cancer. ROR2 is a potential therapeutic gene target for cancer given the success of other receptor tyrosine kinases.
Design: In this study, breast cancer tissue microarrays containing 236 cases of ductal carcinoma in situ, 223 cases of invasive ductal carcinoma, and 106 metastatic breast cancers were stained with an anti-ROR2 antibody. Cores were evaluated for circumferential membranous staining, consistent with the HER2/neu scoring criteria.
Results: 10.17% (24/236) of ductal carcinoma in situ cases and 11% (25/223) of invasive breast carcinoma cases are ROR2-positive. Notably, in the invasive cancers, ROR2 expression was not correlated with HER2 amplification. Among ROR2-positive metastases, 100% (3/3) of the corresponding primary carcinomas lesions are also positive. Overall positivity in metastases is 5.5% (6/106).
Conclusions: Overall, 10% of ductal carcinoma in situ and invasive carcinoma cases express ROR2. ROR2 expression may represent a clinically useful therapeutic target.
Wednesday, March 6, 2013 1:00 PM
Poster Session VI # 7, Wednesday Afternoon