Purpose: To analyze the frequencies of two single nucleotide polymorphisms (SNPs) of EGFR gene, -191C/A and 181946G/A, among lung cancer patients from the Republic of Srpska, Bosnia and Hercegovina, as well as to assess the association of SNP genotypes with the cancer type and other demographic characteristics of patients, particularly with the smoking status.
Methods: This study enrolled 41 lung cancer patients from the territory of Republic Srpska, Bosnia and Herzegovina. Detection EGFR SNPs was performed using PCR-RFLP methodology. PCR was performed on 2720 Thermal Cycler (Applied Biosystems, United States). PCR, as well as RFLP products, were detected by gel electrophoresis. SPSS-17 software (SPSS, Inc.) was used for statistical analyses.
Results: There was significantly more male than female smokers in our cohort (p=0.006). In addition, the proportion of smokers was higher among patients with adenocarcinoma in comparison to patients with other lung cancer types (p=0.044). Adenocarcinoma was less common in patients older than 64 years (p=0.035). The wild type homozygous genotype of both SNPs was the most frequent genotype in all the tested demographic groups. Using dominant genetic model for -191C/A SNP, we observed statistically significant association of -191CC genotype and adenocarcinoma (p=0.043) in the subgroup of patients younger than 64 years. Namely, patients younger than 64 years and carriers of -191CC genotype had higher risk (odds ratio/OR=9.6; 95% confidence interval/CI= 0.8477 to 108.7214) for adenocarcinoma than the ones carrying -191CA or -191AA genotype.
Conclusions: Patients younger than 64 years and carriers of -191CC genotype have significantly higher risk for adenocarcinoma than carriers of -191CA or -191AA genotype. Further studies on larger cohorts are necessary to evaluate -191C/A SNP as a potential biomarker.