The prognostic value of cell proliferation in colorectal adenomas assessed with tritiated thymidine and anti-PCNA antibody

AIM: To predict the development of metachronous colorectal adenomas. METHODS: We analyze the cell kinetics of colorectal adenomas by autoradiographic method with tritiated thymidine and immunohistochemical detection with anti-PCNA antibodies. 46 patients who underwent prior endoscopic polypectomy for colorectal adenomas were re-evaluated by colonoscopy every six months for four years. RESULTS: Thymidine Labeling Index (T-LI) ranged from 1.4% to 38.0% with a median value of 10.45%; PCNA Labeling Index (PCNA-LI) ranged from 0% to 27.0% with a median value of 2.55%. Among the 46 patients studied, 16 developed recurrent adenomas (group A) and 30 were free of recurrent adenomas (group B). The median T-LI in group A and in group B were respectively 15.3% and 9%. The median PCNA-LI in group A and in group B were respectively 5.1% and 1.4%. Both labeling indices resulted significant risk factors in predicting adenoma recurrence. CONCLUSIONS: T-LI and PCNA-LI in colorectal adenomas are helpful in the prediction of the possibility of the development of a metachronous adenoma.