Abstract A09: A next generation sequencing based microsatellite instability assay suitable for routine risk stratification in colorectal cancer

In this study, we tested 17 short (7-12bp) mononucleotide markers (previously identified by our team via an in silico analyses of whole genome sequencing data). These 17 markers were able to discriminate between MSI-high (MSI-H) and microsatellite stable (MSS) cases. To define the optimal parameters to discriminate between MSI-H and MSS samples, we tested these 17 markers across a panel of 141 CRC samples. This allowed us to define a scoring scheme for the 17 markers using allelic imbalance based on a linked SNP (called weighted scoring scheme), which achieved 96% sensitivity and 100% specificity. This scoring scheme was then validated using an independent cohort of 70 CRCs without knowing their MSI status. The assay achieved a 100% sensitivity and specificity.We provide here a high throughput tool to detect microsatellite instability that is less costly, uses short mononucleotide markers (eliminating the need to test matched normal tissue) and is validated on formalin fixed paraffin embedded (FFPE) samples (similar to routine samples). The ability to test the microsatellite instability status in all the newly diagnosed CRC cases would have a great clinical impact on prognosis, risk stratification and treatment of CRCs.Citation Format: Ghanim Alhilal, Lisa Redford, Angel Alonso, Sira Moreno, Mark Arends, Anca Oniscu, Ottilia O'Brien, Stephanie Needham, John Burn, Michael Jackson, Mauro Santibanez-Koref. A next generation sequencing based microsatellite instability assay suita...
Source: Cancer Epidemiology Biomarkers and Prevention - Category: Cancer & Oncology Authors: Tags: Improving Cancer Risk Prediction for Prevention and Early Detection: Poster Presentations - Proffered Abstracts Source Type: research