In the subgroup analysis by cancer sites, the Arg194Trp polymorphism was associated with increased risks of lung cancer (OR = 1.27 and 95%CI: 1.07-1.50 for Trp/Trp versus Arg/Arg + Arg/Trp) and esophageal cancer (OR = 1.68 and 95%CI: 1.33-2.13 for Trp/Trp versus Arg/Arg + Arg/Trp).
Two non-synonymous polymorphisms Arg194Trp and Arg399Gln in the DNA-base excision repair gene X-ray repair cross-complementing group 1 (XRCC1) have been implicated in risk for esophageal cancer.