Clinical significance of retinoblastoma protein (pRB) expression in esophageal squamous cell carcinoma

✍ Scribed by Ikeguchi, Masahide; Oka, Shinichi; Gomyo, Yoshihito; Tsujitani, Shunichi; Maeta, Michio; Kaibara, Nobuaki

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 106 KB
• Volume: 73
• Category: Article
• ISSN: 0022-4790
• DOI: 10.1002/(sici)1096-9098(200002)73:2<104::aid-jso9>3.0.co;2-7

✦ Synopsis

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 ‫ס‬ 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 ‫ס‬ 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 ‫ס‬ 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.