BACKGROUND AND OBJECTIVES: The goal was to evaluate the clinicopathological significance of retinoblastoma gene product (pRB) expression in esophageal squamous cell carcinoma. METHODS: We investigated abnormal pRB expression in tumors in 191 patients using an immunohistochemical method in conjunction with anti-RB protein antibody. Surgically resected esophageal squamous cell carcinomas were examined by immunohistochemical analysis for altered pRB expression. RESULTS: Decreased pRB nuclear staining indicating loss of RB function occurred in 82 (43%) of the cases studied. The incidence of decreased pRB expression was higher in tumors with invasion to the adventitia (50%) than in tumors without invasion to the adventitia (33%, P = 0.0188). In addition, the incidence of decreased pRB expression was higher in tumors with lymph node metastasis (50%) than in those without (34%, P = 0.0346). The 3-year survival rates of 82 patients who had tumors with decreased pRB expression (30%) was significantly lower than that of 109 patients who had tumors with normal pRB expression (52%, P = 0.0032). However, in the multivariate survival analysis, pRB expression was not an independent prognostic factor for patients with esophageal squamous cell carcinoma. CONCLUSIONS: Abnormal pRB expression appears to be closely associated with tumor development. However, the existence of tumors with hyperphosphorylated RB protein (inactivated form) in pRB-positive tumors, such as those in the present study, should be considered. Thus, discrimination of this hyperphosphorylated form of RB protein from the unphosphorylated RB protein is needed. Copyright 2000 Wiley-Liss, Inc.
BACKGROUND AND OBJECTIVES: The goal was to evaluate the clinicopathological significance of retinoblastoma gene product (pRB) expression in esophageal squamous cell carcinoma. METHODS: We investigated abnormal pRB expression in tumors in 191 patients using an immunohistochemical method in conjunction with anti-RB protein antibody. Surgically resected esophageal squamous cell carcinomas were examined by immunohistochemical analysis for altered pRB expression. RESULTS: Decreased pRB nuclear staining indicating loss of RB function occurred in 82 (43%) of the cases studied. The incidence of decreased pRB expression was higher in tumors with invasion to the adventitia (50%) than in tumors without invasion to the adventitia (33%, P = 0.0188). In addition, the incidence of decreased pRB expression was higher in tumors with lymph node metastasis (50%) than in those without (34%, P = 0.0346). The 3-year survival rates of 82 patients who had tumors with decreased pRB expression (30%) was significantly lower than that of 109 patients who had tumors with normal pRB expression (52%, P = 0.0032). However, in the multivariate survival analysis, pRB expression was not an independent prognostic factor for patients with esophageal squamous cell carcinoma. CONCLUSIONS: Abnormal pRB expression appears to be closely associated with tumor development. However, the existence of tumors with hyperphosphorylated RB protein (inactivated form) in pRB-positive tumors, such as those in the present study, should be considered. Thus, discrimination of this hyperphosphorylated form of RB protein from the unphosphorylated RB protein is needed. Copyright 2000 Wiley-Liss, Inc.
Authors: Simone S Contu; Paulo C Contu; Daniel C Damin; Renato B Fagundes; Fabiano Bevilacqua; Aline S Rosa; João C Prolla; Luis F Moreira Journal: World J Gastroenterol Date: 2007-03-21 Impact factor: 5.742