摘要
Objective.To d etermine whether the non-expression of DPC4protein only occurs late in the dev el-opment of colorectal carcinoma.Methods.In this study,we examined the ex pression of DPC4protein in formalin-fixed archival specimens from102colorec tal neoplasm with immunohistochemical analysis.Those specimens were classi-fie d into5stages:stageⅠ;stageⅡ(intramucosal carcinoma ,8cases);stageⅢ(primary invasive carcinoma without infiltration of the l ymph nodes,11cases);stageⅣ(primary invasive carcinoma with infiltration of the lymph nodes,25cases);and stageⅤ(carcinoma metastasized to dis-ta nt tissue,22cases).Results.The frequency of non-expression of DPC4prote ins were5.5%in stage I,12.5%in stage II;9% in stage III;36%in stage IV;32%in stag e V.The frequency of negative expression of DPC4protein were analyzed by÷ 2 test for stage II and III versus stage IV and V and there was statistically significant difference.At same time ,there was statistically signifi-cant differencefor adenoma versus carcinoma .Conclusions.The frequency of non-expression of DPC4protein increases as the stage of colorectal carcinoma advances and the non-expressio n of DPC4protein is likely to be a late event in the sequential pathogenesis o f colorectal carcinoma.The non-expression DPC4protein in colorectal neoplasm may sug-gest its malignant characteristic,which will help us to increase the insight on colorectal carcinoma.
