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Date of Award

Spring 2011

Author's School

College of Arts & Sciences

Author's Department/Program

Biology

Abstract

Uveal melanoma is the most common primary cancer of the eye. While there exist multiple treatment options to remove or destroy the primary ocular tumor, about half of patients develop metastatic disease, often in the liver, which is almost always fatal. We have previously developed a 15-gene PCR assay that can accurately assess the risk of metastasis for primary tumors. While this test has been positively evaluated on fine needle aspirate biopsy (FNAB) samples, there are no data to confirm whether our test can accurately classify formalin fixed, paraffin embedded (FFPE) archival samples. Such an analysis is of particular importance for uveal melanoma patients who had the affected eye removed, but fresh tissue could not be obtained. Here, in collaboration with the Collaborative Ocular Melanoma Study (COMS), we evaluate the accuracy of our 15- gene PCR assay on 117 archival COMS FFPE samples along with an additional 46 more recent FFPE samples collected at Barnes Jewish Hospital over the past ten years. Our results indicate a reduced accuracy of classification observed in FFPE samples compared to the original larger study of FNAB tumor samples. This reduction was tied to the misclassification of a handful of Class 2 tumors. We explore the possibilities that tumor heterogeneity and RNA degradation by FFPE might be the underlying factors obscuring the accuracy of our test and conclude that the RNA degradation is likely the dominant force responsible for the misclassifications observed.

Language

English (en)