Polymorphisms in the epidermal growth factor receptor gene and the risk of primary lung cancer: a case-control study

Polymorphisms in Epidermal Growth Factor Receptor (EGFR) gene may influence EGFR production and/or activity, thereby modulating susceptibility to lung cancer. To test this hypothesis, we investigated the association between polymorphisms in the EGFR gene and the risk of lung cancer in a Korean population. We first examined the frequencies of 39 candidate polymorphisms in the EGFR gene in 27 healthy Korean individuals. After then, we genotyped five polymorphisms (127378C>T, 142285G>A, 162093G>A, 181946C>T and 187114T>C) that have variant allele frequencies greater than 10%, in 582 lung cancer patients and in 582 healthy controls. Of the 5 polymorphisms, the 181946C>T genotype distribution was significantly different between the cases and controls (P = 0.04). Compared with the 181946 CC + CT genotype, the 181946 TT genotype was associated with a significantly decreased risk of lung cancer (adjusted OR = 0.63, 95% CI = 0.45-0.88, P = 0.007). When the analyses were stratified by smoking status, the protective effect of the TT genotype was statistically significant in ever-smokers (adjusted OR = 0.59, 95% CI = 0.41-0.86, P = 0.007), but not in never-smokers (adjusted OR = 0.89, 95% CI = 0.45-1.75, P = 0.73; P = 0.08, test for homogeneity). Consistent with the results of the genotyping analysis, the CGGCT haplotype with the 181946C allele was associated with a significantly increased risk of lung cancer compared to the CGGTT haplotype carrying the 181946T allele (adjusted OR = 1.50, 95% CI = 1.09-2.07, P = 0.012 and Bonferroni corrected P-value = 0.048). These results suggest that the EGFR polymorphisms, particularly the 181945C>T polymorphism, could be used as markers for the genetic susceptibility to lung cancer.