Promoter methylation data from genomic DNA in patient with rectal cancer

The identification of surrogate methylation markers that can predict responses to preoperative chemoradiotherapy (CRT) in rectal cancer patients. Genome-wide association studies in clinical populations are theoretically capable of identifying markers that are capable of tumor regression after CRT. We used Infinium® Methylation Assay to detail methylation status of patient’s group showing differential responsiveness to preoperative CRT and profiled SNP biomarkers. The chemoradiosensitivity of tumor tissue from the initial cohort of 45 patients was assessed using clinical responses of tumor regression grade (TRG). TRG was clinically categorized as complete response (CR) as TRG 1, dominant response (ER or finally as DR) as TRG 1 and 2, and efficient response (RYN or finally as ER) as TRG 1, 2, and 3 (TRG grade from Mandard et al, 1994). Examination of genome-wide DNA methylation in 45 colon cancer tissues. We separated patients into TRG1,2,3,4 and 5 group after chemoradiotherapy(CRT). As proposed by Mandard et al. TRG 1, complete tumor response; TRG2, residual cancer cells scattered through fibrosis; TRG 3, an increased number of residual cancer cells, with predominant fibrosis; TRG 4, residual cancer outgrowing fibrosis; and TRG 5, no regressive changes within the tumor: Responders (TRG 1 and 2) and nonresponders (TRG 3?5). Mandard et al. Cancer 1994 Group 1 and Group 2 in ER, CR and RYN was divided by TRG classification. CR: group 1 - TRG 2,3,4 and 5; group 2 - TRG 1 ER: group 1 - TRG 3,4,5; group 2 - TRG 1 and 2 RYN: group 1 - TRG 4 and 5; group 2 - TRG 1,2 and 3