Cancer staging is one of the cornerstones of modern oncology.
The TNM classification system developed by the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) provides a common language that allows physicians worldwide to describe the extent of disease, estimate prognosis, compare outcomes, and guide treatment recommendations. Without a universally accepted staging system, meaningful interpretation of the oncologic literature would be impossible.
For decades, HPV-associated and HPV-unrelated oropharyngeal cancers were staged identically. The introduction of the AJCC 8th Edition represented a major paradigm shift. For the first time, HPV-associated oropharyngeal cancer received its own dedicated staging system.
The consequences were dramatic. Almost every HPV-positive patient was down-staged even from Stage IV disease down to Stage I. This was not because the disease had become less advanced. Rather, the old staging system failed to reflect the true prognosis of HPV-associated cancer (which is the basic aim of the TNM system). And the implications were enormous. Every study published before the introduction of HPV-specific staging must be interpreted with caution. Historical outcome data, survival analyses, and even some treatment recommendations were generated using a classification system that no longer accurately reflects the biological reality of HPV-driven disease.
The AJCC has moved away from the traditional model of releasing a new “edition” every several years and has adopted a more dynamic “version” system. The goal is to allow staging systems to evolve more rapidly as new evidence becomes available, even at different times across disease sites.
Where to find AJCC Content:
- Commercial software and applications through AJCC API or AJCC DLL
- Individual subscriptions through AJCC Staging Online containing both AJCC 8th edition and Version 9
- Individual purchases through Amazon ebook or print
- Facility or institution through library services
For HPV-associated oropharyngeal cancer, Version 9 provides refinements intended to improve prognostic accuracy. The most clinically relevant modification affects pathological nodal staging. In practical terms, pathological N classification has become slightly more stringent: previously less than 4 N+ nodes was pN1, and more than 4 pN2, there was no pN3. Now 1 N+ is pN1a, 2 to 4 pN1b, and more than 4 pN2. If ENE is present, less than 4 is pN2, and more than 4 pN3. Some patients who would previously have received a lower pathological nodal stage may now be assigned a higher category.
Although the impact on overall stage grouping is modest, this adjustment reflects growing evidence regarding the prognostic significance of nodal burden in surgically treated patients. However, the last update of the NCCN guideline for Head&Neck Cancer (version 2.2026) still remarks that “ The recomendations for patients at high risk with ENE and positive margins are based on randomized studies involving patients for whom the HPV status of their tumors was not specified“.
The change in the pathological staging is important because postoperative treatment decisions often depend on pathological findings, and there is a clear trend towards primary surgical treatment for patients with HPV-Associated Oropharyngeal Cancer.
AJCC Version 9 for HPV-associated oropharyngeal cancer became effective in January 2026. It is the CURRENT staging system. Clinicians should already be applying Version 9 in routine practice, and institutional databases, research registries, and outcome reporting systems should be updated accordingly.
Cancer treatment has always been personalized. But “personalized” is acquiring a new meaning with AI
Perhaps the most interesting question is whether traditional staging systems themselves will eventually become insufficient. TNM remains extraordinarily valuable because it provides a simple, reproducible framework that can be used worldwide. However, in many ways, cancer treatment has always been personalized. Experienced clinicians have long integrated patient characteristics, comorbidities, pathology findings, functional outcomes, and other considerations into treatment decisions. But “personalized” treatment is acquiring a new meaning with AI.
J Granell. Jun 15, 2026