Effect of sampling procedure on the quality control metrics of cytoscan HD array for studying cytogenetic aspects of colorectal cancer.

OBJECTIVES: The method of colorectal cancer (CRC) tissue sampling would affect its molecular profile and the downstream processing. In this study, we described the impact of CRC tissue sampling procedures on the quality control (QC) metrics of cytoscan HD array. METHODS: We employed a high-resolution cytoscan HD microarray platform to investigate the chromosomal aberrations that could be associated with CRC. We compared the tissue extraction procedures and their impact on the QC parameters from the cytoscan HD array determined by chromosome analysis software (Suite3.1). Median of absolute values of all pairwise differences (MAPD), waviness-standard deviation (Waviness-SD), and single nucleotide polymorphism QC (SNPQC) were the QC parameters that were analyzed. RESULTS: From 67 patients, we collected 843 colorectal tissues. Of these, 65.7% were obtained through endoscopic procedures, and the rest was after surgical resections. The mean transit time between tissue excision and preservation was 26 ± 15.5 and 74.6 ± 24.8 min, respectively. The tissues extracted from the surgical procedure showed mean MAPD of 0.28 ± 0.06 compared to 0.24 ± 0.06, for endoscopy, P = 0.005, degree of waviness-SD of 0.20 ± 0.1 compared to 0.2 ± 0.1, P = 0.64, and SNPQC of 9.6 ± 4.2 compared to 11.1 ± 4.6, P = 0.23. CONCLUSIONS: This report provides objective results that can help in tissue sampling intended to be used for DNA based molecular studies. Tissue collection protocol should be optimized to support microarray-analysis methods. Tissue extraction from endoscopic procedures had faster transit time and relatively better quality metrics outcome than surgical procedures. However, surgical procedures have less refusal rate, higher tissue quantity, and less negative results for malignancy.