Prognostic significance of tumour progression and human papillomavirus in advanced tonsillar cancer classified as stage IVa

Objective: To identify clinical factors that can explain the differences in treatment outcome, and examine the value of human papillomavirus infection as a prognostic biomarker in stage IVa tonsillar carcinomas. Methods: Fifty-nine patients with tonsillar carcinoma classified as stage IVa were retrospectively analysed for survival outcomes according to various clinical factors. Human papillomavirus infection was evaluated using a human papillomavirus DNA chip test and immunohistochemical staining for p16 and p53. Results: Lower disease-free survival rates were associated with increasing local invasiveness and nodal status. Although human papillomavirus positivity and p16 expression was more common in locally advanced tonsillar carcinomas with advanced nodal status, the overall survival rate was better for patients with human papillomavirus positive, p16-positive tumours. Conclusion: The disease-free survival rate may differ according to local tumour invasiveness and nodal status, even for stage IVa tonsillar cancers. Human papillomavirus infection may be a useful biomarker for predicting treatment outcomes for stage VIa tumours.