EP578 Detection of lymph vessel invasion and blood vessel invasion using double D2–40 and CD31 immunohistochemistry reveals independent prognostic significance of blood vessel invasion in endometrial cancer

Introduction/Background Lymph-vascular space invasion (LVSI) is adverse prognostic factor in endometrial cancer (EC). Due to lack in histologic criteria and interobserver variability its role in administering adjuvant treatment and predicting recurrence isn´t well defined. The aim of our study was to utilize sensitive immunohistochemical method for separate detection of lymph vessel invasion (LVI) and blood vessel invasion (BVI) in patients with EC and to investigate their prognostic impact. Methodology We retrospectively identified from the institutional database 217 patients with EC and with complete follow-up, between 2002 and 2006. Tumor specimens were retrieved and two-colored double staining immunohistochemistry (D2-40/CD31) was performed to highlight lymphatic and blood vessels in the same slide. Tumors were divided in three groups: LVSI negative, LVI positive and BVI positive. Results In the original pathology reports, LVSI was misclassified in 36 (16.6%) tumors. In this study by using immunohistochemistry LVI was detected in 64 (29.5%) and BVI in 32 (14.7%) cases. All tumors with positive BVI also had accompanying LVI. BVI had the strongest impact on the risk for recurrence (OR 9.27 CI 4.47–19.22; p Conclusion Our results suggest that BVI could have greater clinical value in contrast to isolated LVI, and that therapeutic decisions should be based on its presence. We hope that these preliminary results will encourage further application of this inexpensive, readily available technique. Disclosure Nothing to disclose.