High prevalence of EGFR R479K (rs2227983) polymorphism in Indian Head and Neck Cancer Patients: Association with Unfavourable Clinical Outcome

The Epidermal growth factor receptor (EGFR) gene, is one of the most altered genes reported across various cancers. Polymorphism exists in the EGFR gene, and R497K (rs2227983) is a common single nucleotide polymorphism (SNP) of the gene that affects the protein's function. The current study was done to screen for EGFR R497K polymorphism in Indian patients with Head and Neck squamous cell carcinoma (HNSCC) and study the effect of this polymorphism on disease prognosis. In HNSCC patients (n = 50), genomic DNA was extracted, and polymerase chain reaction coupled with restriction fragment length polymorphism (PCR-RFLP) technique was applied for screening. In the cohort, 84% of patients carried the EGFR R497K variant in either homozygous (6%) or heterozygous (78%) condition and only 16% were wild type. We re-confirmed our PCR-RFLP data with Sanger sequencing. Kaplan-Meier statistical analysis was used to correlate the SNPs in patients to survival factors. Analysis revealed a decreased overall survival (OS) and progression-free survival (PFS) in the patients carrying the R497K polymorphism compared to the wild-type patients. This study concludes that the prevalence of R497K of the EGFR gene is high in Indian HNSCC patients and it is associated with poor prognosis.