ESTRO 2025 - Abstract Book

S1076

Clinical – Head & neck

ESTRO 2025

Conclusion: “Tonsil/BOT” tumors were much more common than other OPSCC with a marked increase in HPV-association over time. The frequency of p16-expression and lack of prognostic impact seen in tumors arising in the “distant subsites” is comparable to that of non-oropharyngeal HNSCC. This indicates that grouping all p16-positive OPSCC as one entity for staging and prognostication, as currently done in TNM8, is probably too simple as it does not accurately depict the differences in biology and the consequent treatment response of the tumors.

Keywords: Oropharynx cancer, subsite, HPV