Influence of polymorphisms in DNA repair genes ERCC1 and XRCC1 on curative effect of three-dimen-sional conformal radiotherapy for esophageal squamous cell carcinoma

CHUN Caipu; ZHU Jinsong; LIAN Wenyong; GAO Haixia; ZHANG Fengli; YUAN Weijun

Abstract：Objective To investigate the association between the risk of esophageal squamous cell carcinoma(ESCC) and polymorphisms in DNA repair genes ERCC1 and XRCC1 as well as the influence of polymorphisms on curative effect of three?dimen?sional conformal radiotherapy( 3D?CRT) for ESCC. Methods The peripheral blood samples from 218 ESCC patients were assigned as disease group and 230 cases of healthy normal people were assigned as control group. The PCR method was used to amplify the target gene fragment. The single nucleotide polymorphisms(SNP) of ERCC1 rs3212986, ERCC1 rs11615, XRCC1 rsl799782 and XRCC1 rs25487 were detected by direct sequencing. The distribution of different genotypes and alleles as well as their correlation with the risk of ESCC were analyzed. According to the RECIST 1?1, the 154 cases treated with 3D?CRT for advanced ESCC were divided into effec?tive group and ineffective group, and the relationship between the above SNP loci and curative effects of 3D?CRT for ESCC were further analyzed. Results The genotype distributions of the 4 SNP loci were consistent with the Hardy?Weinberg equilibrium in both groups. The distribution of ERCC1 rs3212986, ERCC1 rs11615 genotype and allele, and XRCC1 rs25487 allele in the disease group was sig?nificantly different from those of the control group( P<0?05) . When the wide homozygous of XRCC1 rs3212986, XRCC1 rs11615 and ERCC1 rs25487 were used as reference, the risk of mutant homozygous for ESCC was elevated. When the wide allele gene of 4 SNP lo?ci were used as reference, the risk of mutant allele for ESCC was higher( P<0?05) . Among 154 patients, 113 cases were divided into effective group(35 CR+78 PR) and 41 groups and the ineffective group(24 SD+17 PD). There were significant differences in the effi?ciency of different genotypes and allele of 4 SNP loci( P<0?05) . When the wide homozygous were used as reference, the risk of invalid radiotherapy in mutant homozygous was higher. The risk of the mutant allele genes for invalid radiotherapy was higher than that of the wide allele genes( P<0?05) . Conclusion ERCC1 and XRCC1 gene polymorphisms are associated with the risk of esophageal squa?mous cell carcinoma. The risk of invalid radiotherapy was elevated in advanced ESCC patients with mutate homozygous and allele genes.