Comparison of Thyroid Transcription Factor-1 (TTF-1) Expression by Two Monoclonal Antibodies in Lung and Non-Lung Primary Tumors
A Matoso, W Greaves, R Tavares, L Noble, MB Resnick, RA DeLellis, LJ Wang. Rhode Island Hospital/Brown University, Providence, RI
Background: TTF-1 is a nuclear protein that plays a role in the morphogenesis of the thyroid and lungs. Expression of TTF-1 has been used as a marker of lung and thyroid clinically. There are currently two commercially available clones of TTF-1 antibodies, 8G7G1/1 and SPT24. Comperat et al.(Mod Pathol 2005; 18:1371-6) reported TTF-1 positivity in 10% of metastatic and 5% of primary colonic carcinomas with the SPT24 antibody in contrast to no positive cases with 8G7G1. To further assess the comparative specificities ans sensitivities of these antibodies, we examined TTF-1 expression in primary tumors of the lung, prostrate, pancreas, stomach and salivary glands.
Design: Tissue microarrays were created from archival paraffin embedded tissue samples from 374 patients with primary lung tumors, 104 prostate adenocarcinomas, 110 gastric adenocarcinomas, 110 pancreatic adenocarcinoma and 58 salivary gland tumors. None of the patients with non-lung tumors had a history of lung cancer. The microarrays were immunostained with monoclonal antibodies to TTF-1, clones 8G7G1/1(Dako) and SPT24 (Novocastra), using Dako Autostainer with Daki Envision Plus kit.
Results: Only cases with nuclear staining were considered to be positive.
|Large cell (47)||22(46.8%)||17(36.2%)||0.201|
|Squamous cell (97)||14(16.8%)||1(1.0%)||0.003|
|SALIVARY GLAND (56)||1(1.8%)||1(1.8%)||NA|
|PANCREATIC ADENOCARCINOMA (110)||0(0%)||0(0%)||NA|
Conclusions: TTF-1 SPT24 clone is more sensitive than 8G7G1 for detection of primary lung tumors of all histologic subtypes. Importantly, the SPT24 clone detects a significant number of squamous cell carcinomas in contrast to 8G7G1. A small proportion of non-pulmonary tumors, i.e. 1-2% of prostate, gastric primary adenocarcinomas and salivary gland adenocarcinomas are positive with both clones. SPT24 is more sensitive than 8G7G1 for the detection of lung tumors, but both antibodies have similar specificities.
Monday, March 9, 2009 8:15 AM
Platform Session: Section F, Monday Morning