甲状腺转录因子1在肺癌中的表达及应用

TTF-1 expression and its diagnostic application in lung carcinomas

目的观察甲状腺转录因子1(TTF1)在肺肿瘤中的表达差异,探讨其在鉴别诊断中的应用。方法134例肺叶切除标本中,肺原发癌105例,肺转移性腺癌29例。原发癌中,非小细胞癌(NSCLC)76例,其中腺癌42例,鳞状细胞癌30例,大细胞癌4例;小细胞癌(SCLC)28例;复合性癌(小细胞癌与鳞状细胞癌复合存在)1例。通过免疫组织化学染色,观察TTF1在肿瘤中的表达情况。结果判定+阳性瘤细胞占6%～25%;++阳性瘤细胞占26%～50%;+++阳性瘤细胞占51%～75%;++++阳性瘤细胞>76%。结果TTF1在小细胞肺癌的表达率最高,为82.1%(23/28),而在鳞状细胞肺癌的表达率为0(0/30),两者之间差异有显著性(P<0.001)。TTF1在肺腺癌的表达率为73.8%(31/42),其表达与分化程度及亚型分类无关(P均>0.05)。在29例肺转移腺癌中,除1例甲状腺滤泡癌TTF1表达为阳性外,其余均为阴性。组织自身对照中的间质成分及淋巴细胞等TTF1染色全部为阴性。结论根据TTF1在肺不同肿瘤内的差异表达结果,可将其用于小细胞肺癌与鳞状细胞肺癌、小细胞肺癌与肺炎症或淋巴瘤的鉴别;TTF1对肺组织的特异性表达,有助于对肺原发腺癌及转移腺癌的鉴别。

Objective To detect the expression of thyroid transcription factor 1(TTF 1) and study its application in the diagnosis of lung carcinomas. Methods Of 134 specimens from lung lobectomy, 105 were primary lung carcinomas including 76 non small cell carcinomas (NSCLCs), 28 small cell lung cancers (SCLCs) and 1 complex carcinoma(SCLC and SCC), and 29 were metastatic carcinomas. Expression of TTF 1 was detected by immunohistochemistry. The expression level of TTF 1 was graded as, +:6% to 25% of tumor cells positive, ++:26% to 50%, +++:51% to 75%, and ++++:> 76%. Results The positive nuclear immunoreactivity of TTF 1 was identified in 23 of 28 SCLCs (82.1%), but none in squamous cell cancer (SCC) ( P <0.001). The positive expression rate of TTF 1 in lung adenocarcinomas (ACs) was 73.8% (31/42). There was no correlation between TTF 1 expression and ACs differentiation or ACs subtypes ( P >0.05). All but one (thyroid follicular carcinoma) metastatic ACs were TTF 1 positive. Mesenchymal component and lymphoid or inflammatory cells were consistently TTF 1 negative. Conclusion A significant difference of TTF 1 expression may assist in distinguishing SCLC from SCC, lymphoma or inflammatory lesions. Owing to its restrictive expression in lung tissue, TTF 1 might be used to differentiate primary from metastatic adenocarcinoma of the lung.