Simultaneous detection of colorectal cancer mutations in stool samples with biochip arrays

Abstract

Colorectal cancer (CRC) is the second main cause of cancer-related death in the Western world and like many other tumors is curable if detected at an early stage. Current detection options include faecal occult blood testing and invasive direct visualization techniques such as flexible sigmoidoscopy, colonoscopy and barium enema. The availability of a more simple, non-invasive test that detects tumor specific products with optimal analytical performance might overcome barriers among patients who are not willing to undergo more sensitive but invasive tests. One such emerging technology, which has shown promise in recent years, is the analysis of DNA alterations exfoliated from tumor cells into stool. Here we report an analytical platform for non-invasive detection of 28 common mutations within CRC-related genes APC, TP53, K-ras and BRAF in stool samples based on biochip array technology and applied to the semi-automated Evidence Investigator analyzer. Mutation detection was possible in 1000-fold excess of wild type DNA and analysis of 10 CRC-positive patient samples showed presence of targeted mutations with equivalent mutations also identified by an alternative method. This application represents an excellent tool for the multiplex detection of CRC-specific mutations using a single platform.

Keywords

• biochip array technology
• colorectal cancer
• mutation
• non-invasive
• stool