Ki-67 and transforming growth factor alpha (TGF-alpha) expression in colorectal recurrent tumors after endoscopic resection

Ki-67 and TGF-alpha expression were examined immunohistochemically in 7 cases with endoscopically resectcd laterally spreading tumor (LST) and their recurrent tumor (all lesions were adenoma) in order to clarify the difference of their proliferative activity. Average Ki-67 labeling index of recurrent tumors (68.9+/-7.9%) was significantly higher than that of lateral portion of primary tumors (38.2+/-7.1%). Incidence of TGF-a expression of recurrent tumors (6/7; 85.7%) was significantly higher than that of lateral portion of primary tumors (217; 28.6%). These results indicated that proliferative/growth activity of recurrent tumor is significantly higher than that of primary tumors and TGF-alpha expression was correlated with cellular proliferative activity. These suspect that endoscopic resection map have residual tumor get a higher proliferative activity and malignant potential.