PD-0023 - Validation Study of a Blood-based Gene Expression Signature for Colorectal Cancer Detection

Date 27 June 2014
Event World GI 2014
Session Poster discussion session IV - Miscellaneous
Topics Colon Cancer
Rectal Cancer
Pathology/Molecular Biology
Translational Research
Presenter Qinghua Xu
Citation Annals of Oncology (2014) 25 (suppl_2): ii5-ii13. 10.1093/annonc/mdu164
Authors X. Ye, F. Wu
  • bioMerieux, Shanghai/CN

Abstract

Introduction

Colorectal cancer (CRC) is the leading cause of cancer related deaths worldwide. In 2008, more than 1 million cases were newly diagnosed and more than 600,000 people died from the disease. The early detection of CRC is crucial for successful treatment and patient survival. However, compliance with current screening methods remains poor and there is a clear need for an accurate in vitro blood test to increase participation in CRC screening.

Methods

In this study, we validated the performance of our previously reported 18-gene expression signature for CRC based on blood gene expression patterns using an independent cohort. The panel employs quantitative RT-PCR to analyze gene expression of the 18 biomarkers that are differentially expressed in CRC patients as compared with controls. Blood samples from 260 patients (146 CRC and 114 controls) were collected, and total blood RNA was isolated and subjected to quantitative RT-PCR and data analysis.

Results

Our 18-gene expression signature had overall 80.4% accuracy (95%CI: 0.75-0.85), 78.1% sensitivity (95%CI: 0.70-0.84), and 83.3% specificity (95%CI: 0.75-0.89) to discriminate between CRC and control samples in the validation set. The area under the receiver operating characteristics curve reached 0.89 (95%CI: 0.84-0.92). This performance is comparable to the previous results, suggesting the robustness of our 18-gene expression signature. When analyzed with clinical variables like age, gender, tumor site, and stage, results indicated that the 18-gene signature conducted equally well for different categories of patients.

Conclusion

This validation study confirms the accuracy of the 18-gene expression signature in an independent cohort of 114 controls and 146 CRC patients. These results open an avenue for the further development of a blood-based molecular test for the diagnosis and early detection of CRC.