Abstract 1724: A gene expression profile test to resolve squamous cell carcinomas of head & neck from squamous cell carcinomas of the lung

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL The differential diagnosis between squamous cell carcinomas of the head & neck and squamous cell carcinomas of the lung is often unresolved because the histologic appearance of these two tumor types is quite similar. We have developed and validated a gene expression profile test (Pathwork Tissue of Origin Head & Neck Test) that distinguishes head & neck squamous and lung squamous cancers in formalin-fixed, paraffin-embedded (FFPE) specimens using a 2160-gene classification model. The test was validated in a blinded study using a pre-specified algorithm and microarray data files for 76 metastatic, poorly differentiated or undifferentiated FFPE tumor specimens that had either a known head & neck squamous or lung squamous diagnosis. The study met the primary Bayesian statistical endpoint for acceptance. Measures of test performance include overall agreement with the known diagnosis of 82.9% (95% CI, 72.5% to 90.6%), an area under the ROC curve (AUC) of 0.91 and a diagnostics odds ratio (DOR) of 23.6. Head & neck squamous cancers (N=38) gave an agreement with the known diagnosis of 81.6% and lung squamous cancers (N=38) gave an agreement of 84.2%. Reproducibility in test results between three laboratories had a concordance of 91.7%. The Tissue of Origin Head & Neck Test can aid in resolving the important differential diagnostic question for head & neck and squamous cell carcinoma of the lung. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1724. doi:1538-7445.AM2012-1724