Adenoma-cancer sequence using carcinoembryonic antigen in colorectal adenoma with early invasive carcinoma

Immunoperoxidase staining for carcinoembryonic antigen (CEA) was performed on colorectal adenoma with early invasive carcinoma in order to assess its potential diagnostic value. Using formalin-fixed, paraffin-embedded tissues and an immunoperoxidase technique, we have attempted to demonstrate CEA in 10 cases of adenoma with early invasive carcinoma and in adjacent benign mucosa. CEA was demonstrated in adenocarcinoma, in adenoma, and in glycocalyx of surface epithelial cells in normal mucosa. Adenocarcinoma tissues could not readily be identified by immunoperoxidase staining for CEA because the findings had shown a remarkable similarity between adenocarcinoma and adenoma. These findings on adenoma seem to support the view that adenocarcinoma may occur in adenoma and that these polyps have malignant potentiality. As is generally accepted, an adenoma is a precancerous lesion of colorectal cancer. Therefore, the concept of an adenoma-cancer sequence in the colorectal bowel is supported