Objective To investigate the level of cell adhesion molecule sialyl-LeX expression in colorectal carcinoma and its relation with carcinogenesis, differentiation, metastasis and prognosis. Methods Sialyl -LeX expression and its optical density in colorectal carcinoma (n=90) and remote normal mucosa (n=30) were quantitatively studied with microwave-LSAB immunohistochemical method combined with image analysis technique. Fifty-three patients were followed up. Results The weaker staining in remote normal colorectal mucosa was observed in very limited parts of some deep crypts. Positive rate of sialyl-LeX expression was only 16.7%(5/30). The positive expression of sialyl-LeX was observed in 83 of 90 patients with colorectal carcinoma(92.2%). The apical cytoplasma of cancer tubules, the luminal contents, and the cytoplasma of the cancer cells were bly stained. The mean integral optical density of sialyl-LeX positive cell in poorly differentiated adenocarcinoma was significantly higher than that in highly differentiated and mucinous ones (Plt;0.01). It was markedly higher in patients with positive lymphatic nodes than that in negative ones (Plt;0.01). With followed-up for longer than 5 years, it was much lower in the alive cases than that in the dead (Plt;0.01). Conclusion These findings indicate that changes of sialyl-LeX expression and its optical density is related to carcinogenesis, differentiation, invasion and metastasis of colorectal carcinoma. It may be a good predicter for the prognosis of patients with colorectal carcinoma.
