Nomiya Takuma, Nemoto Kenji, Nakata Eiko, Miyachi Hideo, Takai Yoshihiro, Yamada Shogo
Department of Radiation Oncology, Tohoku University School of Medicine, Sendai, Japan.
Oncol Rep. 2004 Dec;12(6):1195-9.
Several studies have shown that macroscopically infiltrative type of esophageal carcinoma generally has a poorer local response to radiation therapy than that of localized type. The aim of this study was to determine the role of metallothionein (MT) as a radioprotective agent in the difference of clinical radiosensitivities in esophageal carcinoma. A total of 45 surgically resected esophageal carcinoma tissues [20 macroscopically localized type without preoperative treatment (PT), 20 macroscopically infiltrative type without PT and 5 macroscopically infiltrative type with PT] were stained for MT by immunohistochemistry and were analyzed. MT expression level of macroscopically localized type of esophageal carcinoma was significantly higher than that of infiltrative type without PT (P=0.026) and was significantly higher than that of infiltrative type with PT (P=0.024). No significant difference was found between MT expression levels in infiltrative type of esophageal carcinoma without PT and that with PT. The results of this study suggest that there is less possibility that clinical radioresistance of the tumor is due to MT expression in esophageal carcinoma and also suggest that there is less possibility that MT synthesis is induced by fractionated irradiation of a moderate dose or by an anti-cancer agent during a course of treatment.
多项研究表明，宏观浸润型食管癌对放射治疗的局部反应通常比局限型食管癌差。本研究的目的是确定金属硫蛋白（MT）作为一种放射防护剂在食管癌临床放射敏感性差异中的作用。通过免疫组织化学对45例手术切除的食管癌组织[20例宏观局限型且未接受术前治疗（PT），20例宏观浸润型且未接受PT，5例宏观浸润型且接受PT]进行MT染色并分析。宏观局限型食管癌的MT表达水平显著高于未接受PT的浸润型（P = 0.026），且显著高于接受PT的浸润型（P = 0.024）。未接受PT的浸润型食管癌与接受PT的浸润型食管癌之间的MT表达水平无显著差异。本研究结果表明，肿瘤的临床放射抗性因食管癌中MT表达所致的可能性较小，也表明在治疗过程中，中等剂量的分次照射或抗癌药物诱导MT合成的可能性较小。
