Following meta-analysis, significant associations were seen for six tumor variants (mutant TP53 and PIK3CA, copy number gain of ERBB2/HER2, CCND1 and FGF3, and chromosomal instability/ploidy) and seven germline polymorphisms: ERCC1 rs3212986, ERCC2 rs1799793, TP53 rs1042522, MDM2 rs2279744, TYMS rs34743033, ABCB1 rs1045642 and MTHFR rs1801133.
The estimated allele frequencies of functional polymorphisms in(of) exon 21 (2677 G>T, Ala893Ser) and exon 26(3435 C>T, Ilel 142I1e) of the MDR] gene were 0.42 and 0.46 in the controls and 0.54 (p=0.035) and 0.60 (p=0.017) in the MSI-H tumors.
We analyzed the C3435T SNP in the MDR1 gene which is associated with altered cellular drug uptake in matched tumor and normal tissues of 45 patients suffering from colorectal carcinoma.