title: Variable sensitivity and specificity of TTF-1 antibodies in lung metastatic adenocarcinoma of colorectal origin.
abstract: Thyroid transcription factor-1 (TTF-1) is considered as a reliable marker for differential diagnosis in distinguishing primary adenocarcinomas of the lung from extrathoracic origins. We previously reported the first case of lung metastasis of colorectal origin, with nuclear expression of TTF-1. As most previous studies were performed on series of extrathoracic primary tumors, we raised the question of a possible role of lung microenviroment in TTF-1 expression. We investigated the rate of TTF-1 expression in lung metastases of extrathoracic adenocarcinomas and compared results of immunohistochemistry performed with different primary antibodies. Two different clones of antibodies (8G7G1/1 from Dako, SPT24 from Novocastra) raised against TTF-1 were used on 56 lung-metastatic malignant tumors, 41 from colorectal origin. A series of primary colorectal (90 cases) and primary pulmonary adenocarcinomas (86 cases) were also investigated. Four of 41 (10%) lung metastases of colorectal adenocarcinomas displayed a nuclear staining for TTF-1 with SPT24 clone. Three of the four positive cases displayed similar nuclear staining in primary and/or other extrathoracic metastatic sites as well as four of 90 (5%) primary colorectal adenocarcinomas, ruling out the role of lung microenvironment. None of them was positive with 8G7G1/1 clone. Sensitivity between two sets of antibodies was compared in 86 primary pulmonary adenocarcinomas. Nuclear staining was detected in 72 cases (84%) with Novocastra's antibody and 56 cases (65%) with Dako's. Significant discordance was observed (P < 0.01). These results suggest that the diagnostic virtue of TTF-1 detection depends on the used antibody's clone. The SPT24 clone seems to have a stronger affinity for TTF-1 protein but may lead to a few positive colorectal adenocarcinomas.
authors.affiliation: Service d'Anatomopathologique de l'Hôtel-Dieu, place du Parvis Notre Dame, Paris, France.
authors.forename: Eva
authors.initials: E
authors.lastname: Compérat
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Cedric
authors.initials: C
authors.lastname: Perrotin
authors.forename: Thierry
authors.initials: T
authors.lastname: Molina
authors.forename: Pierre
authors.initials: P
authors.lastname: Magdeleinat
authors.forename: Beatrice
authors.initials: B
authors.lastname: Marmey
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Régnard
authors.forename: Josee
authors.initials: J
authors.lastname: Audouin
authors.forename: Saphie
authors.initials: S
authors.lastname: Camilleri-Broët
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000378:metabolism* / Q000556:secondary*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies; D000918:Antibody Specificity; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000556:secondary*; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins / Q000276:immunology* / Q000378:metabolism; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D000074482:Thyroid Nuclear Factor 1; D046888:Tissue Array Analysis; D014157:Transcription Factors / Q000276:immunology* / Q000378:metabolism
chemical_list: D000906:Antibodies; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors