Research ArticlesA 6-Antibody Panel for the Classification of Lung Adenocarcinoma Versus Squamous Cell CarcinomaTacha, David PhD*; Yu, Charie MD*; Bremer, Ryan PhD*; Qi, Weiman PhD*; Haas, Thomas DO†Author Information *Biocare Medical, Concord, CA †Mercy Health System, Janesville, WI D. Tacha, C. Yu, R. Bremer and W. Qi are employees of Biocare Medical. T. Haas is a consultant to Biocare Medical. Reprints: David Tacha, PhD, Biocare Medical, 4040 Pike Lane, Concord, CA 94520 (e-mail: [email protected]). Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Website, www.appliedimmunohist.com. Received September 6, 2011 Accepted October 17, 2011 Applied Immunohistochemistry & Molecular Morphology: May 2012 - Volume 20 - Issue 3 - p 201-207 doi: 10.1097/PAI.0b013e31823d7f0e Buy SDC Metrics Abstract Non-small cell lung cancer can be classified into several histologic subtypes, most commonly lung adenocarcinoma (LADC) or squamous cell carcinoma (SqCC). With the introduction of targeted therapies that can result in dramatically different outcomes based on subtype, the importance of accurate classification has been amplified. Six antibodies (Napsin A, Desmoglein 3, TTF-1, CK5, p63, and tripartite motif-containing 29) were selected for evaluation on cases of LADC of lung SqCC. Guided by the sensitivities and specificities determined for individual antibodies, a protocol was developed using a sequential series of 2-antibody cocktails that resulted in the classification of 93% of cases with 100% specificity. Importantly, the initial step in this method, a napsin A+Desmoglein 3 antibody cocktail classified >85% of cases, resulting in <15% of cases requiring further evaluation beyond a single test. Two new antibodies specifically developed and optimized for the diagnosis of LADC and lung SqCC, a rabbit polyclonal Napsin A and a mouse monoclonal Desmoglein 3 [BC11], were the key elements of the antibody panel. Most importantly, the described protocol uses routine interpretation methods and an uncomplicated algorithm for classification. Given the increased difficulty of diagnosing poorly differentiated tumors, the ability of this 6-antibody panel to classify 96% and 87% of moderately and poorly differentiated cases, respectively, is of particular value, especially when limited tissue for molecular testing is an issue. © 2012 Lippincott Williams & Wilkins, Inc.