Genetic Variant XRCC1 rs1799782 (C194T) and Risk of Cancer Susceptibility in Indian Population: A Meta-analysis of Case-Control Studies

Abstract

X-ray repair cross-complementing group 1 (XRCC1) plays a key role in the base excision repair pathway, as a scaffold protein that brings together proteins of the DNA repair complex. Several studies have reported contradictory results for XRCC1 exon 6 C>T (rs1799782) gene polymorphism and cancer risk in Indian population has provided inconsistent results. Therefore, we have performed this meta-analysis to evaluate the relationship between XRCC1 exon 6 C>T gene polymorphism and risk of cancer by published studies. We searched PubMed and Google scholar web databases to cover all studies published on association between XRCC1 exon 6 C>T gene polymorphism and cancer risk. The meta-analysis was carried out and pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to appraise the strength of association. In order to derive a more precise estimation of the association, A total of 3197 confirmed cancer cases and 3819 controls were included from eligible seventeen case-controls studies. Results from overall pooled analysis demonstrated suggested that that variant allele (T vs. C: OR 1.301, 95% CI 1.003-1.688, p = 0.047) was associated with the risk of overall cancer. Other genetic models; heterozygous (TC vs. CC: OR 1.108, 95% CI 0.827-1.485, p = 0.491), homozygous (TT vs. CC: OR 1.479, 95% CI 0.877-2.493, p = 0.142), dominant (TT+TC vs. CC: OR 1.228, 95% CI 0.899-1.677, p = 0.196) and recessive (TT vs. TC+CC: OR 1.436, 95% CI 0.970-2.125, p = 0.071) did not reveal statistical association. Publication bias observation was also considered and none was detected during the analysis. The present meta-analysis suggested that the variant allele T of XRCC1 exon 6 gene polymorphism was associated with the risk of cancer. It is therefore pertinent to confirm this finding in a large sample size to divulge the mechanism of this polymorphism and cancer risk in Indian population.

Keywords: Base excision repair pathway; Cancer; DNA repair gene; Indian population; Meta-analysis; Polymorphism.

Fig. 1

Prisma flow diagram for inclusion and exclusion of studies in the meta-analysis on XRCC1 exon 6 C>T gene polymorphism

Fig. 2

Forest plot of allele (T vs. C) model for overall cancer risk. The squares and horizontal lines correspond to the study specific OR and 95% CI

Fig. 3

Forest plot of heterozygous (TC vs. CC) model for overall cancer risk. The squares and horizontal lines correspond to the study specific OR and 95% CI

Fig. 4

Forest plot of homozygous (TT vs. CC) model for overall cancer risk. The squares and horizontal lines correspond to the study specific OR and 95% CI

Fig. 5

Forest plot of dominant (TT+TC vs. CC) model for overall cancer risk. The squares and horizontal lines correspond to the study specific OR and 95% CI

Fig. 6

Forest plot of recessive (TT vs. TC+CC) model for overall cancer risk. The squares and horizontal lines correspond to the study specific OR and 95% CI