Aim: We examined the relationship between p16, a surrogate marker of human papilloma virus (HPV), and FOXP3, marker of regulatory T-cells, in tonsillar squamous cell carcinoma (TSCC), and assessed their prognostic potential.
Materials and methods: The tumors of 79 patients with locally advanced TSCC treated from 2000 to 2008 were subjected to immunohistochemistry (IHC) assays for p16 and FOXP3 using tissue microarrays.
Results: Sixty-three tumors (80%) were p16-positive and 38 (48%) were FOXP3-positive on IHC. FOXP3 correlated positively with p16 (p=0.011). The p16-positive group had a significantly higher 5-year overall survival (OS) rate than the p16-negative group [78% vs. 63%, hazard ratio (HR)=0.347, p=0.025]. The FOXP3-positive group had a significantly higher 5-year OS rate than the - negative group (89% vs. 61%, HR=0.158, p=0.003). Multivariate analysis indicated that FOXP3 is an independent prognostic factor (HR=0.11, p=0.001) but p16 did not reach statistical significance (HR=2.17, p=0.131).
Conclusion: FOXP3 expression is associated positively with p16 expression, and is a favorable prognostic factor for survival in TSCC.
Keywords: FOXP3; HPV; Tonsillar squamous cell carcinoma; p16; regulatory T-cell.