Epigenetic clonality confers por prognosis in colorrectal cancer patients (technical replicates)

In CRC, 1) to identify epigenetic changes at inter-tumor and intra-tumor level, and 2) to relate intra-tumor clonality to clinical, molecular and histopathologic parameters. From 79 FFPE tumors, 3 different regions were macrodissected: invasive front (IF), digestive tract surface (DTS) and central bulk (CB). Clinical, molecular, and histopathologic parameters were stablished. Epigenetic analysis was performed using Infinium 450K beadchip (Illumina) and R statistics. Intra-tumor regions clustered together by patient. The biggest epigenetic changes were in IF vs DTS/CB. By patient, the most often divergent region was IF (49.4%) comparing with DTS and CB (25.3% in both). It did not correlate with histopathologic, molecular and clinical parameters.Epigenetic clonality is higher at intra-tumor level. The highest changes are observed in IF vs DTS/CB. No association with histopathologic, molecular, and clinical characteristics was found. Technical replicates of 12 samples previously hybridized on the Infinium HumanMethylation450 to demonstrate technique robustness. From 79 FFPE tumors, 3 different regions were macrodissected: invasive front (IF), digestive tract surface (DTS) and central bulk (CB). When available, metastasis and normal tissue were also collected.