HPV-related head and neck cancer: clinical features and implications for tumor staging and therapeutic strategies

In this dissertation, head and neck tumours caused by the human papillomavirus (HPV) were studied. The ‘tracing’ role of the HPV-positive cervical lymph nodes that provide an early indication of a smaller primary oropharyngeal tumour was discovered. The data showed such a reduced prognostic value of the HPV-positive lymph gland that an adaptation of the TNM classification necessitated a separate staging for HPV-related oropharyngeal tumours. The addition of non-anatomic parameters (smoking habits, age) to this staging allows for a more careful stratification of treatment groups, for example, when investigating outcomes of the promising HPV-targeted immunomodulation. This dissertation further shows that HPV-targeted diagnostics are currently based on a balance between accuracy and clinical applicability, and that both components need improvement. In lymph node metastases of unknown primary tumours, HPV diagnostics do not contribute to a more accurate detection of the primary tumour. However, de-escalation of irradiation volumes appears to be safe (i.e. without pharyngeal axis, and control side neck, in glands <3cm), which leads to less disease burden in this group.