Project description:Colorectal adenomas are common precancerous lesions with the potential for malignant transformation to colorectal adenocarcinoma. Endoscopic polypectomy provides an opportunity for cancer prevention, however, recurrence rates are high. We collected formalin-fixed paraffin-embedded tissue of fourteen primary adenomas with recurrence, fourteen primary adenomas without recurrence, and fourteen matched pair samples (primary adenoma and the corresponding recurrent adenoma). These samples were analysed by array-based comparative genomic hybridisation (aCGH) to understand the dynamics of copy number alterations (CNAs) and to identify molecular markers to predict recurrence. ACGH analysis confirmed the genetic landscape specific for colorectal tumorigenesis, i.e., CNAs of chromosomes 7 (13.7%), 13q (13.7%), 18 (5.8%) and 20q (13.7%). CNAs were detected in 41/51 (80.4%) of colorectal adenomas (2N). Focal aberrations (≤10 Mbp) were mapped to chromosome bands 6p22.1-p21.33 (33.3%), 7q22.1 (31.4%) and 16q21 (29.4%). Gains of CDX2 were exclusively seen in adenomas with recurrence compared to adenomas without recurrence. However, the average number of copy alterations failed to discriminate primary adenomas with recurrence from primary adenomas without recurrence.
Project description:In total, 89 samples were collected from 89 patients with colorectal cancer (CRC), of which 66 patients had stage IV CRC. We sequenced the mRNAs purified from the formalin-fixed paraffin embedded (FFPE) blocks.
Project description:RAS genotyping is mandatory for the prescription of anti-EGFR (epidermal growth factor receptor) therapies in patients with metastatic colorectal cancer. The standard genotyping is assessed on formalin-fixed paraffin embedded tumour tissue. This study compares RAS and BRAF genotyping results achieved in analyzing circulating plasma DNA using OncoBEAM technique with those achieved using the standard genotyping techniques and formalin-fixed paraffin embedded samples.