Automated TTF-1 Immunohistochemistry Assay for the Differentiation of Lung Adenocarcinoma Versus Lung Squamous Cell Carcinoma.

Due to therapeutic advances, the subclassification of non-small cell lung carcinomas (NSCLC) between the adenocarcinomas and squamous cell carcinomas subtypes is essential for the practice of personalized and targeted medicine. The clinical management for these two NSCLC subtypes is different due to their different molecular properties and histological origins. Immunohistochemistry (IHC) markers such is TTF-1 play a key role in the differentiation of lung adenocarcinomas and squamous cell carcinomas. However, immunohistochemistry is a complex process involving many critical steps and the reliability of results depends on the standardization of the assay as well as the appropriate interpretation. Different laboratories use different reagents and different IHC approaches for the detection of TTF-1 in lung cancer tumors. Here we describe an automated IHC protocol used in our laboratory for the detection of TTF-1 in formalin-fixed, paraffin-embedded (FFPE) tissue sections from lung tumors.