Distribution of carcinoembryonic antigen and biologic behavior in colorectal carcinoma

PURPOSE: Carcinoembryonic antigen is assumed from the results of several ex periments to be associated with invasion of colorectal carcinoma by adhesio n or contact inhibition. The patterns and the intensity of carcinoembryonic antigen distribution in colorectal carcinoma were assessed to verify wheth er they were correlated with malignant potential from those biologic charac teristics. METHODS: Carcinoembryonic antigen distribution was tested in the archival samples of 149 colorectal carcinomas by immunohistochemistry, usi ng three characterized anti-carcinoembryonic antigen monoclonal antibodies: T84.66, PR1A3, and PR3B10. The distribution patterns in neoplastic tissue were categorized into unstained, apicoluminal, and diffuse-cytoplasmic patt erns. Tumor, invasive tumor margin, and tissue surrounding the tumor were e xamined. RESULTS: Although all three antibodies revealed a positive correla tion, T84.66 showed better discrimination than the others. Although none of the negative staining of the tumor or invasive tumor margin showed recurre nce, the apicoluminal pattern showed recurrence, and the diffuse pattern sh owed the most frequent recurrence (P < 0.01). Recurrence was also associate d with staining intensity in the apicoluminal pattern in both the tumor and invasive tumor margin (P < 0.05). Infiltrative tumor growth and lymph node metastasis were more frequent in cases of positive staining in tissue surr ounding the tumor. Patients with the apicoluminal pattern achieved longer s urvival than patients with the diffuse-cytoplasmic pattern in the invasive tumor margin (P = 0.024) by a multivariate analysis including tumor stage a nd histologic differentiation. CONCLUSION: The distribution of carcinoembry onic:antigen in tumors and surrounding tissue seems to be closely correlate d with invasiveness and metastatic behavior in colorectal carcinoma. Carcin oembryonic antigen immune staining can be considered as an efficient tool t o determine groups with risk of recurrence.