Abstract:Objective:To determine the relationship between chronic colonic schistosomiasis and colorectal carcinoma. Methods:Expression levels of c-erbB-2 and DPC4 were detected by two-step and SP immunohistochemical method respectively in normal colonic mucosa of 15 cases, in colonic mucosa of 15 cases with simple schistosomiasis, 20 cases of colorectal carcinoma with schistosomiasis and 20 cases of colorectal carcinoma without schistosomiasis. Results:c-erbB-2 was expressed in each group with different levels, but the level in colonic mucosa with schistosomiasis was the highest compared to other groups, which had statistical significance (P<0.05). DPC4 was also expressed in each group with different levels, but the level in normal colonic mucosa was the highest compared to other groups, which had statistical significance(P<0.05).Conclusions:There is a high correlation between chronic schistosomiasis japonica in colon and colorectal carcinoma. Alteration of expression levels of c-erbB-2 and DPC4 may be an early stage molecular event during the course of malignant change of mucosal epithelium caused by chronic colonic schistosomiasis.