MSIplus for Integrated Colorectal Cancer Molecular Testing by Next-Generation Sequencing.

Area of Science:

• Oncology
• Genetics
• Molecular Diagnostics

Background:

• Current molecular analysis of colorectal cancers involves multiple tests, increasing costs and delaying patient care.
• Existing methods for detecting cancer gene mutations and microsatellite instability (MSI) have varying performance and limitations.

Purpose of the Study:

• To develop and validate a single, next-generation sequencing (NGS) assay for simultaneous detection of key colorectal cancer gene mutations (KRAS, NRAS, BRAF) and MSI status.
• To evaluate the performance characteristics of this integrated assay compared to conventional testing methods.

Main Methods:

• Development of a single NGS assay utilizing an amplicon sequencing approach.
• Simultaneous evaluation of colorectal cancer specimens for mutations in KRAS, NRAS, and BRAF genes.
• Assessment of tumor microsatellite instability (MSI) using the developed assay and comparison with conventional multiplex PCR MSI testing.

Main Results:

• The NGS assay achieved 100% sensitivity and 100% specificity for detecting cancer-associated mutations, with a limit of detection at 2% mutant allele fraction.
• MSI detection demonstrated 97% sensitivity and 100% specificity, outperforming conventional multiplex PCR MSI testing (97% sensitivity, 95% specificity).
• The assay is rapid, requires no matched normal material, and is suitable for specimens with limited or fragmented DNA.

Conclusions:

• The integrated NGS assay provides a sensitive, specific, and efficient method for simultaneous molecular profiling of colorectal cancers.
• This approach simplifies testing, reduces costs, and accelerates patient care by providing comprehensive genetic and MSI status from a single assay.
• The assay's ability to handle limited DNA and its automated analysis pipeline ensure reproducible and reliable results.