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Journal of Clinical Oncology, 2007 ASCO Annual Meeting Proceedings (Post-Meeting Edition).
Vol 25, No 18S (June 20 Supplement), 2007: 21130
© 2007 American Society of Clinical Oncology
Gene profiling validation for cancer classification using known primary carcinoma samples
R. Lenzi,
A. Rashid,
N. Ordonez,
N. M. Raber,
G. R. Varadhachary,
A. Floore,
L. Stork-Sloots,
M. Warmoes,
M. Erlander and
J. L. Abbruzzese
MD Anderson Cencer Center, Houston, TX; Agendia BV, Amsterdam, The Netherlands; AviaraDx, San Diego, CA
21130
Background: Cancer of Unknown Primary Site (CUP) accounts for 35% of all malignant neoplasms. With current diagnostic procedures, approximately 20% of CUP patients have a primary identified. Since formulation of prognosis and treatment selection depends largely on the primary type, diagnostic uncertainty unfavorably affects CUP management. Gene expression profiling has permitted the development of diagnostic classifiers. A clinically usable methodology needs to differentiate a sufficiently large number of primary types. This study focuses on the estimate of the accuracy of gene expression for classification of metastatic tumors in formalin fixed (FF) FNA and core/surgical biopsies. Methods: CupPrint® is a 1900 gene microarray optimized for FF samples which uses a database of 643 cancer profiles to provide a robust method for the discrimination of 51 tumor (sub) types. Metastasis samples of six known primary carcinoma types were studied (lung, pancreas, colorectal, breast, liver, ovary/primary peritoneal carcinoma). To examine the impact of the metastatic site on diagnostic accuracy different biopsy sites were studied, including lung, brain, lymph nodes, liver, peritoneum. Samples were deemed evaluable that contained an estimated >33% tumor cells. mRNA samples from the metastatic lesions were provided in a blinded fashion to the microarray laboratory. Results: For 39 evaluable samples studied so far, the CupPrint® prediction was compared with the pathologic diagnosis. Of the 39, in 34 the primary site of origin was correctly predicted (87% accuracy). In two of the incorrectly predicted samples the site of biopsy (brain and liver respectively) was reported as the primary site. Correlations of molecular profiles to clinical parameters are being explored. Conclusions: CupPrint® appears to be sufficiently accurate to be of potential clinical utility in the diagnosis of CUP.
No significant financial relationships to disclose.
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