Angiogenesis index (AI) as a predictor of tumor burden in lymph nodes in colon cancer (Cca) patients (pts) undergoing sentinel lymph node (SLN) mapping (M)

14509 Background: Lymph Node (LN) status is the most important prognostic factor in colon cancer (Cca). Angiogenesis Index (AI) has been studied as a prognostic marker in various solid tumors with conflicting results. Hence, a retrospective analysis was done to evaluate the role of AI as a prognostic marker in Cca. Methods: Pts with Cca who underwent SLNM to determine LN status were included. A portion of tumor was sent for tumor marker analysis including p53, Thrombospondin-1 and CD31 by IHC. AI was derived for each specimen by summing the biomarker specific score for the three tumor markers. AI of -ve 6 was taken as cut off for significance based on previous studies on solid tumors. Metastatic foci in SLNs and non-SLNs were measured in greatest diameter by ocular micrometer; and were added for each pt to estimate overall tumor burden in SLNs and non-SLNs. Results: A total of 111 consecutive pts with Cca were included in the study. SLNM was successful in 100% pts. Pts with distant metastasis (mets) (n=18...