Combined with magnifying endoscopy,narrow-band imaging (NBI) contrasts microvascular architecture on lesion surface.The histology of early colorectal lesions could be predicted under NBI view.However,its capability for estimating invasion depth remains to be verified.The study is based on the hypothesis:NBI can predict histology and invasion depth,combined with the verification of microvessel count and MMP-7 expression.

The microvessel count (MVC) is a classical method of assessing histologic grade.To verify whether NBI could predict histology through microvascular architecture,we measured lesion microvessels by immunohistochemistry.On the other hand,we applied immunohistochemistry of matrix metalloproteinase-7 (MMP-7) to validate the capability of NBI for estimating invasion depth.MMP-7 is directly involved in the processes of growth, invasion, and metastasis of colorectal cancer.Our target was to clarify the diagnostic accuracy of magnifying NBI in early colorectal lesions,combined with the verification of microvessel count and MMP-7 expression.

Inclusion Criteria:

• patients of early colorectal lesions with capillary pattern(CP) type II&III,initially detected by white-light view and then examined by NBI with magnifying endoscopy.

Exclusion Criteria:

• lesions with CP type I;
• CP type III lesions with an obvious appearance of advanced cancer;
• lesions that had underwent biopsy;
• patients with inflammatory bowel disease(IBD) or familial adenomatous polyposis(FAP)
• patients with previous colorectal surgery;
• having conditions associated with cardiac,hepatic,renal,and coagulopathy diseases.

patients with early colorectal lesions