Prognostic impact of CD31 antigen expression in anal canal carcinoma

Background/Aims: CD31 is a platelet endothelial cell adhesion molecule. Thu s CD31 immunostaining of vascular endothelial cells can be used to measure degree of angiogenesis. As angiogenesis is necessary for tumor growth and m etastasis, microvessels density could be a predictor of prognosis. The purp ose of this study was to examine the relationship between CD31 value and st andard pathologic parameters and prognosis of anal canal carcinoma. Methodology: Twenty-four patients with anal canal carcinoma were evaluated. Five-mum sections of formalin-fixed, paraffin-embedded tissue were tested with monoclonal anti-CD31 antibody. CD31 value is considered positive if mo re than 185 vessels/mm(2) were counted. Pearson's chi (2) test was employed to test for association between CD31 value and clinicopathological variabl es. Results: We found no correlation between CD31 value and histologic type, ly mph node involvement, patients age and neoplastic relapse. Significant corr elation was found between CD31 score and depth of parietal invasion. Conclusions: The relapse type could strengthen the hypothesis that increase d vascularity promotes neoplastic dissemination. As angiogenesis could be u sed as prognostic indicator to determine patients who may be at higher risk for relapse, our results warrant further confirmation. Development of mark ers of angiogenic activity in anal canal carcinoma must be an integral part of proper clinical trials.