A review of the 8th edition of the AJCC staging system for oropharyngeal cancer according to HPV status

Background The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has increased substantially in recent decades, particularly p16-positive human papillomavirus (HPV)-related OPSCC, which has risen by 50% in western countries. HPV-positivity is the most favourable non-anatomic predictor of oropharyngeal cancer outcomes, which underscores the importance of incorporating this variable into the cancer staging system. Methods In the present article, we review the differences between the 7th and 8th editions of the AJCC staging system, with particular focus on the role of HPV-positivity in patients with head and neck cancer. Results In the previous edition (7th edition) of the AJCC/UICC manual, HPV status and its correlation with nodal metastasis were not considered, thereby leading to incorrect lymph node (N) staging and, potentially, inadequate treatment and worse outcomes. The 8th edition of the AJCC manual addresses these issues, providing more accurate discrimination between groups and better risk stratification in patients with HPV-positive OPSCC. In the future, additional adjustments are likely to be needed, such as unification of the pathological and clinical staging models. Conclusions The new staging system is substantially more accurate than the previous system and should be widely adopted in routine clinical practice.