Analysis of biomarker expression in severe endometriosis and determination of possibilities for targeted intraoperative imaging

Objective: To evaluate the expression of biomarkers in endometriotic tissue in order to determine the most promising molecules for targeted intraoperative imaging. Methods: Tissue samples were obtained from 18 patients with endometriosis. The intensity and pattern of expression of the following biomarkers were assessed by immunohistochemistry: C-X-C chemokine receptor type 4 (CXCR4), epithelial cell adhesion molecule (EpCAM), estrogen receptor (ER), folate receptor alpha (FR-alpha), hypoxia-inducible factor 1-alpha (HIF-1 alpha), progesterone receptor (PR), and vascular endothelial growth factor A (VEGF-A). The Target Selection Criteria scoring system was used to select the most promising biomarkers for intraoperative imaging. Results: Expression of OCCR4, EpCAM, ER, PR, and VEGF-A was scored as strong in endometriotic epithelium. Expression of FR-alpha was detected in 94.4% of samples, whereas HIF-1 alpha was expressed in just 5.6% of samples. Of note, CXCR4, ER, and VEGF-A were also expressed in surrounding healthy tissue, thus reducing the target-to-background ratio. Conclusion: Of the 7 biomarkets assessed in the present study, EpCAM, FR-alpha, and VEGF-A seem the most promising for targeted intraoperative imaging of endometriosis. (C) 2012 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.