Oral squamous cell carcinoma risk investigation in tobacco addicts and fanconi anemia patients with egfr and CTNNB1 gene variant analysis

Oral squamous cell carcinoma (OSCC) is one of the most common types of cancer. The use of tobacco and Fanconi Anemia (FA) increases the risk of developing this disease. Epidermal growth factor receptor (EGFR) and Cadherin Related Protein Beta-1 (CTNNB1) genes function in signaling pathways which are effective in the development of various cancer types. In our study, we aim to research the effect of EGFR rs845561 and CTNNB1 rs3864004 gene variants in OSCC and compare FA patients who carry OSCC risk with tobacco addicts and healthy individuals. 29 OSCC patients, 33 FA patients, 20 tobacco addicts and 20 non-smoking healthy individuals were included in this study, and gene variant analyses were conducted with Sanger Sequencing Method. EGFR rs845561 TT genotype was found to be less in Stage 2 OSCC patients (p=0,02). A correlation between T allel frequency and tumor perineural invasion was found (p=0,05). C allel frequency was lower in OSCC patients with lymph node metastase (p=0,001). It is remarkable that in FA patients who developed OSCC, T allele frequency is higher (p<0,03). In tobacco addicts, TT genotype was found to be related to poor oral hygiene and oral wounds (p=0,01 and p=0,01). CTNNB1 rs3864004 A allele frequency was found to be related to increased tumor invasion (p=0,01) and failure to respond to chemotherapy/ radiotherapy (p=0,04 and p=0,03). G allel frequency is lower in OSCC patients who have lymph node metastase (p=0.05). OSCC patients with poor oral hygiene have less GG genotype (p=0,012). In FA patients, G allel frequency was found to be lower than the control group (p=0.02). As a result, EGFR rs845561 and CTNNB1 rs3864004 gene variants were observed to be significantly related to OSCC development, tumor invasion and response to therapy.