DISCUSSION
In this case–control study of Chinese NSCLC patients and healthy
control patients, we determined an association between XRCC3 and
XRCC4 SNPs or other known risk factors and NSCLC susceptibility.
We found five SNPs, including rs861537 and rs1799794 in XRCC3
and rs6869366, rs1056503 and rs9293337 in XRCC4, to be associated
with NSCLC risk in both adjusted and unadjusted models. For
example, the rs1799794 G allele in the XRCC3 gene was inversely
associated with NSCLC risk (GG vs homozygote AA), whereas the
rs861537 AG or AA genotype and XRCC4 rs6869366 had a
significantly increased NSCLC risk. In contrast, minor allele carriers
of XRCC4 rs1056503 and rs9293337 were inversely associated with
NSCLC risk. In addition, 26 pack-year tobacco smokers, a family
history of lung cancer, ETS exposure, CGAA/CGAA in XRCC3 and a
negative mental status were risk factors in NSCLC development. The
data from this study indicate that gene–environment interactions have
an important role in NSCLC development.