Ser326Cys polymorphism in hOGG1 gene and risk of esophageal cancer in a Chinese population

Ser326Cys polymorphism in the hOGG1 gene, which is involved in the repair of 8‐hydroxyguanine in oxidatively damaged DNA, has been identified and the variant genotype appears to be related to susceptibility to certain cancers. We investigated the association between Ser326Cys polymorphism and squamous‐cell carcinoma of the esophagus among a Chinese population. hOGG1 gene polymorphism was detected by PCR‐based single‐strand conformation polymorphism and DNA sequencing among 201 normal controls and 196 patients with esophageal cancer from Linxian, China, a high‐risk area for the disease. The association between this genetic polymorphism and risk of the cancer was examined by a multivariate analysis. We found that the distribution of hOGG1 Ser326Cys genotypes among controls (Ser/Ser, 33.8%; Ser/Cys, 52.8%; and Cys/Cys, 13.4%) was significantly different from that among esophageal cancer cases (39.8%, 38.8% and 21.4%, respectively) (p < 0.05). Homozygosity for the Cys/Cys genotype significantly increased the risk of developing esophageal squamous‐cell carcinoma, with the odds ratio (OR) adjusted for age, sex and smoking being 1.9 (95% confidence interval [CI] = 1.3–2.6). Although smoking alone also significantly increased esophageal cancer risk in this case‐control study (adjusted OR = 2.6; 95% CI = 1.7–3.9), no significant interaction between smoking and the Cys/Cys genotype was observed in terms of risk. Our results suggest that the hOGG1 326Cys allele might play a role in the carcinogenesis of the esophagus. © 2001 Wiley‐Liss, Inc.