Effects of KRAS Mutation and Polymorphism on the Risk and Prognosis of Oral Squamous Cell Carcinoma

[[abstract]]Background Mutations or single nucleotide polymorphism (SNP) of relevant genes may affect the risk and prognosis of malignancies. The purpose of this study was to analyze whether the KRAS polymorphisms and mutations can be useful prognostic or risk markers in oral squamous cell carcinoma (OSCC). Methods DNA was extracted from tumor tissues of 47 patients with OSCC and blood cells of 84 normal controls and subjected to sequencing for the KRAS. Results No mutation in the KRAS was found in 47 OSCC samples. However, 2 polymorphisms (rs1137282 and rs712) were detected. Individuals with KRAS SNP rs712 genotypes of G/T or T/T have a reduced risk for OSCC than those with genotype G/G (hazard ratio [HR], 0.26; 95% confidence interval [CI], 0.10–0.60; p = .004). The overall survival between different SNPs were not statistically significant (p = .147 for rs1137282 and p = .202 for rs712). Conclusion These data demonstrate a role for rs712 polymorphism of the KRAS in susceptibility of OSCC. © 2011 Wiley Periodicals, Inc. Head Neck, 2011 Head and neck cancer is one of the 10 leading cancers all over the world. In Taiwan, oral squamous cell carcinoma (OSCC) is the most prevalent tumors of the head and neck cancer. Radical surgery remains the major modality in treating patients with OSCC. However, the locoregional failure rate is still high for patients with advanced-stage disease, even postoperative adjuvant radiotherapy with/without chemotherapy delivery.1–3 Identification of useful biomarkers related to both cancer susceptibility and prognosis is an important approach that could improve treatment outcome. Recent advances in molecular biology have demonstrated that mutations or single nucleotide polymorphism (SNP) of the relevant genes may affect the risk and prognosis of many malignancies. In addition, understanding of the oncogenesis pathway has resulted in successful development of several targeted drugs in the market. Functional genomic analysis identified epidermal growth factor receptor (EGFR) activation as the most common genetic event in OSCC.4 High EGFR expression had been reported to be associated with poor prognosis in OSCC.5 The KRAS protein is known as an important downstream molecule of the EGFR pathway.6 Thus, KRAS mutations or polymorphisms may play a role in predicting cancer formation or treatment outcome. The purpose of this study was to analyze whether the KRAS polymorphisms and mutations can be useful prognostic or risk markers in Taiwanese OSCC