SNP arrays in matched colorectal cancer and normal colonic mucosa.

We analyzed, by last-generation high-resolution SNP arrays, colorectal adenocarcinoma samples and matched normal colonic tissues in order to determine the number of tumor-associated copy number abnormalities (CNAs) and copy neutral-loss of heterozygosity (CN-LOH) regions per patient and to identify possible recurring genomic abnormalities. 69 tumoral bioptic samples, deriving from 51 patients, were collected directly after surgical resection. The mean age was 66.86 years (SD 14.29) for 29 male patients and 69.77 (SD 13.41) for 22 female patients. In 16 patients, two samples were taken at arbitrary positions in the tumor area, separated by at least 1 cm (double-sampling pairs, indicated as tumoral sample 1 or 2). In one patient a sample from a synchronous colorectal adenocarcinoma was also collected (tumoral sample 3). In 28 cases biopsies of adjacent normal mucosa (at distance of 3-6 cm from the tumor) were also collected (matched tumor/mucosa pairs).