Correlation between narrow-band imaging endoscopy results and hPTTG expression indicated by angiogenensis and its distribution in the initial phase of colorectal adenoma-carcinoma sequence.

The aim of the present study was to investigate the correlation between vascular characteristics under narrow band imaging endoscopy (NBI) and the expression of angiogenic factors of colorectal carcinoma and adenoma, and to evaluate the feasibility and validity of NBI in vivo visualizing angiogenesis. Patients with colorectal polyps, which were pathologically confirmed as early carcinoma, adenoma and hyperplastic polyp, were recruited and examined by NBI. The endoscopic vascular pattern was classified by Showa classification. Immunohistochemical staining was performed by cluster of differentiation (CD34), microvessel density (MVD) and Human Pituitary Tumor-Transforming Gene (hPTTG). The histologic results were compared with the vascular pattern under NBI. Overall, 83 colorectal lesions including 9 intramucosal colorectal carcinomas, 44 adenomas (18 tubular adenomas, 26 tubulovillous adenomas) and 30 hyperplastic polyps were recruited and examined by NBI. A higher proportion (88.6%, 47/53) of intramucosal carcinomas and adenomas were more likely to have the dense pattern (DP) or network pattern (NP), while that of hyperplastic polyps was only 30.0% (9/30). There was an obvious increase in the MVD-CD34 counting from hyperplastic polyps, to adenoma to carcinoma, and a significant difference among the three groups as well. Also, a clear difference can be seen in the expression of hPTTG, which was expressed more in carcinoma than in adenoma and HP group (P < 0.05). Conclusion: NBI might be a useful tool as in vivo visualizing angiogenesis. hPTTG expression in colorectal adenoma and carcinoma is related to angiogenesis.