Translating tumor biology into personalized treatment planning: analytical performance characteristics of the Onco<it>type </it>DX^®Colon Cancer Assay

• Main Authors: Krishnakumar Jayadevi, Sangli Chithra, Clark-Langone Kim M, Watson Drew
• Format: Article
• Language: English
• Published: BMC 2010-12-01
• Series: BMC Cancer
• Online Access: http://www.biomedcentral.com/1471-2407/10/691

<p>Abstract</p> <p>Background</p> <p>The Onco<it>type </it>DX^®Colon Cancer Assay is a new diagnostic test for determining the likelihood of recurrence in stage II colon cancer patients after surgical resection using fixed paraffin embedded (FPE) primary colon tumor tissue. Like the Onco<it>type </it>DX Breast Cancer Assay, this is a high complexity, multi-analyte, reverse transcription (RT) polymerase chain reaction (PCR) assay that measures the expression levels of specific cancer-related genes. By capturing the biology underlying each patient's tumor, the Onco<it>type </it>DX Colon Cancer Assay provides a Recurrence Score (RS) that reflects an individualized risk of disease recurrence. Here we describe its analytical performance using pre-determined performance criteria, which is a critical component of molecular diagnostic test validation.</p> <p>Results</p> <p>All analytical measurements met pre-specified performance criteria. PCR amplification efficiency for all 12 assays was high, ranging from 96% to 107%, while linearity was demonstrated over an 11 log₂concentration range for all assays. Based on estimated components of variance for FPE RNA pools, analytical reproducibility and precision demonstrated low SDs for individual genes (0.16 to 0.32 C_Ts), gene groups (≤0.05 normalized/aggregate C_Ts) and RS (≤1.38 RS units).</p> <p>Conclusions</p> <p>Analytical performance characteristics shown here for both individual genes and gene groups in the Onco<it>type </it>DX Colon Cancer Assay demonstrate consistent translation of specific biology of individual tumors into clinically useful diagnostic information. The results of these studies illustrate how the analytical capability of the Onco<it>type </it>DX Colon Cancer Assay has enabled clinical validation of a test to determine individualized recurrence risk after colon cancer surgery.</p>