Genetic and Epigenetic Determinants of Response to Fluorouracil-based Adjuvant Chemotherapy in Patients With Stage III Colorectal Cancer

Genomic DNA extracted from paired fresh-frozen tumor and normal tissues is used for KRAS mutations, BRAF mutations, PIK3A mutations, and EGFR mutations, etc., by sequencing and for MSI analysis by PCR and capillary electrophoresis.

Genomic DNA extracted from paired fresh-frozen tumor and normal tissues is used for specific gene methylation or CIMP status analysis by MethyLight or bisulfite sequencing. Whole-genome bisulfite sequencing will be used to identify novel candidate set of predictive markers.

RNA extracted from paired fresh-frozen tumor and normal tissues or serum is used for specific gene expression analysis by real-time reverse-transcription PCR (RT-qPCR). RNA-seq will be used to identify novel candidate set of predictive markers.

Genomic DNA extracted from serum is used for specific SNP analysis by using sequencing. GWAS with SNPs array will be used to identify novel candidate set of predictive markers.

Tissue microarray made from formalin-fixed paraffin-embedded (FFPE) paired tumor and normal tissues is used for specific protein expression analysis by immunohistochemistry staining.