Immunohistochemical expression of FAP and PCNA in neoplastic epithelial colonic lesions

Abstract

Background Colorectal carcinoma is one of the leading causes of morbidity and mortality worldwide. Fibroblast-activation protein is expressed in cancer-associated fibroblasts and its expression is upregulated during the transformation of benign colorectal tissue into cancer. Proliferating-cell nuclear antigen expression was used as a marker of cell proliferation and is considered as a marker able to identify aggressive adenomas that may in turn become malignant. Aim To study the expression of fibroblast-activation protein and proliferating-cell nuclear antigen in neoplastic epithelial colonic lesions and their role in adenoma–carcinoma sequence. Patients and methods This retrospective study aimed to evaluate the expression of fibroblast-activation protein and proliferating-cell nuclear antigen in 80 cases of neoplastic epithelial colonic lesions. Results In malignant colorectal epithelial tumors, high fibroblast-activation protein expression was detected with an increase in histological grade, depth of invasion, vascular invasion, and lymph-node metastasis. No fibroblast-activation protein expression was detected in all benign cases. In included benign cases, there was a significant relation between proliferating-cell nuclear antigen labeling index and both histological type and grade of dysplasia. In the included malignant cases, there was a significant relation between proliferating-cell nuclear antigen labeling index with grade of tumor and the depth of invasion. Conclusions Both fibroblast-activation protein and proliferating-cell nuclear antigen labeling index suggested to have a role in early detection of malignant transformation and had a prognostic role in malignant cases.