Effects of ERCC1 expression in peripheral blood on the risk of head and neck cancer

Squamous cell carcinoma of the head and neck (SCCHN) accounted for 3.5% of all cancers registered in Korea during 2001. Although tobacco smoking and alcohol consumption are known risk factors of SCCHN, only a small fraction of the populations exposed to tobacco or alcohol develop SCCHN. Therefore, differences in the susceptibility of SCCHN with respect to DNA repair and xenobiotic metabolisms have focused upon attempts to determine the causes of SCCHN. Here, we investigated factors that affect ERCC1 mRNA expression in peripheral blood. The study subjects were all Koreans (67 patients and 73 control subjects); 72.9% of all subjects were male; 68.4% were current or former smokers; and 62.4% were current or former alcohol drinkers. We also studied the association between ERCC1 mRNA expression and the C8092A polymorphism of ERCC1, and found lower ERCC1 mRNA expression in SCCHN patients than in controls (P<0.01). In the present study, we found that ERCC1 C8092A polymorphism is not related to the risk of SCCHN or expression of ERCC1 mRNA. In addition, we found a positive association between ERCC1 mRNA expression in peripheral blood and tumour tissues and inverse associations between ERCC1 mRNA expression and age or the number of cigarettes smoked. Therefore, our study suggests that ERCC1 mRNA expression is reduced by age and smoking and has a weak effect on SCCHN risk as compared with the effects of age and tobacco-smoking expression.