AIM:To identify the role of survivin in colorectal carcinogenesisand the relationship between Survivin and histologicaldifferentiation grade of colorectal carcinoma.METHODS:Immunohistochemical staining of survivin byusing the monoclonal antibody was performed by thestandard streptavidin-peroxidase (SP) technique for the 188paraffin sections which included 30 normal colorectalmucosas,41 adenomas with low grade dysplasia,30adenomas with high grade dysplasia,and 87 colorectalcarcinomas which were classified as high,middle and lowdifferentiated subgroups which included 33,28,26 casesrespectively.RESULTS:Expression of survivin was observed in thecytoplasm of adenoma with dysplasia and colorectalcarcinoma cells.No immunoreactivity of survivin was seenin normal mucosas.The positive rate of survivin increasedin the transition from normal mucosas to adenomas withlow grade dysplasia to high grade dysplasia/carcinomas(0.0 %,31.7 %,56.7 % and 63.2% respectively).But thedifference between high grade dysplasia and carcinomashad no statistical significance.Positive rate was not relatedto histological differentiation grade of colorectal carcinoma.Moreover,there was no correlation between histologicaldifferentiation grade of colorectal carcinoma andimmunoreactive intensity of survivin.CONCLUSION:The expression of survivin is the essentialevent in the early stage of colorectal carcinogenesis andplays an important role in the transition sequence and it isnot related to histological differentiation grade of colorectalcarcinoma.It thus may provide a new diagnostic andtherapeutic target in colorectal cancer. AIM: To identify the role of survivin in colorectal carcinogenesis and the relationship between Survivin and histological differentiation of colorectal carcinoma. METHODS: Immunohistochemical staining of survivin byusing the monoclonal antibody was performed by the standard streptavidin-peroxidase (SP) technique for the 188 paraffin sections which included 30 Normal colorectal mucosas, 41 adenomas with low grade dysplasia, 30 adenomas with high grade dysplasia, and 87 colorectal carcinomas which were classified as high, middle and low differentiated subgroups which included 33, 28, 26 cases were statistically ly.RESULTS: Expression of survivin was observed in the cytoplasm of adenoma with dysplasia and colorectalcarcinoma cells. No immunoreactivity of survivin was seen in normal mucosas. The positive rate of survivin increasedin the transition from normal mucosas to adenomas withlow grade dysplasia to high grade dysplasia / carcinomas (0.0%, 31.7%, 56.7% and 63.2% respectively) .But thedifferencebetween high grad e dysplasia and carcinomashad no statistical significance. Positive rate was not relatedto histological differentiation grade of colorectal carcinoma. Moreover, there was no correlation between histological differentiation grade of colorectal carcinoma andimoreactive activity of survivin. CONCLUSION: The expression of survivin is the essentialevent in the early stage of colorectal carcinogenesis andplays an important role in the transition sequence and it isnot related to histological differentiation grade of colorectalcarcinoma. It may provide a new diagnostic and therapeutic target in colorectal cancer.