TTF-1 has been the premier marker for lung adenocarcinoma. A new and promising marker, Napsin A, is expressed in type II pneumocytes and in adenocarcinomas of the lung (2). Studies have shown Napsin A to be more sensitive and specific than TTF-1 in lung adenocarcinomas and virtually negative in all squamous carcinomas. In other studies comparing TTF-1 and SP-A, Napsin A stained more tumor cells and a higher percentage of lung adenocarcinomas than either of these antibodies (1-3). Other studies have shown that when TTF-1 and Napsin A are used in combination, a higher sensitivity and specificity is achieved (4). A critical assessment is essential for correct diagnosis as patients with squamous carcinoma (SqCC) cannot receive Avastin due to a 30% mortality rate as a result of fatal hemoptysis (hemorrhaging). Therefore, when used in a panel with p63 and CK5, this unique multiplex antibody reagent of TTF-1 and Napsin A may aid in the analysis of poorly differentiated lung adenocarcinomas vs. squamous cell carcinomas in formalin-fixed paraffin-embedded tissues.
Datasheets & SDS
1. Hirano T, et. al. Usefulness of TA02 (Napsin A) to distinguish primary lung adenocarcinoma from metastatic lung adenocarcinoma. Lung Cancer. 2003 Aug; 41 (2):155-62.
2. Ueno T, Linder S, Steterger G. Aspartic proteinase napsin is a useful marker for diagnosis of primary lung adenocarcinoma. Br J Cancer. 2003 Apr 22; 88(8):1229-33.
3. Suzuki A, et. al. Napsin A is useful to distinguish primary lung adenocarcinoma from adenocarcinomas of other organs. Pathol Res Pract. 2005; 201 (8-9):579-86.
4. Dejmek A, et. al. Napsin A (TA02) is a useful alternative to thyroid transcription factor-1 (TTF-1) for the identification of pulmonary adenocarcinoma cells in pleural effusions. Diagn Cytopathol. 2007 Aug; 35(8):493-7.
5. Center for Disease Control Manual. Guide: Safety Management, NO. CDC-22, Atlanta, GA. April 30, 1976 “Decontamination of Laboratory Sink Drains to Remove Azide Salts.”
6. Clinical and Laboratory Standards Institute (CLSI). Protection of Laboratory workers from occupationally Acquired Infections; Approved guideline-Third Edition CLSI document M29-A3 Wayne, PA 2005.