Transforming growth factor beta 1 genotype and p16 as prognostic factors in head and neck squamous cell carcinoma.
ABSTRACT Transforming growth factor β1 gene (TGFβ1) genotype is a potential p16 independent prognostic factor predicting response to chemoradiotherapy in head and neck squamous cell carcinoma (HNSCC).
Expression of p16 and epidermal growth factor receptor (EGFR) has been reported to be associated with survival in HNSCC. We have previously reported that genetic polymorphism of TGFβ1 is linked with survival in HNSCC patients who have undergone chemoradiotherapy. We evaluate here whether TGFB1 genotype can serve as a prognostic factor independent of tumor p16 and EGFR expression.
Expression of p16 and EGFR was studied by immunohistochemistry in tumors from 130 HNSCC patients. Peripheral blood DNA was used to genotype 95 patients for single nucleotide polymorphism rs1800470 within the TGFβ1 gene. The minimum follow-up time was 31 months.
p16 overexpression was associated with an improved disease-free survival (hazard ratio (HR) = 0.39, 95% CI 0.19-0.78), whereas no evident association was observed between EGFR expression and disease-free survival (HR = 0.90, 95% CI 0.68-1.19). Among the 37 patients who had received chemoradiotherapy, TGFβ1 genotype was associated with disease-free (HR = 0.44, 95% CI 0.19-1.02) and overall survival (HR = 0.31, 95% CI 0.12-0.80) independent of tumor p16 expression.