In terms of pathological characteristics, the <i>ABCC1</i> SNP rs35628 and the <i>ABCB1</i> SNP rs2032582 were significantly associated with tumor size, the <i>ABCC2</i> SNP rs2273697 was significantly associated with estrogen receptor status, and the <i>ABCG2</i> SNP rs2231142 was significantly associated with axillary lymph node status.
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.