The role of human papillomavirus marker p16 in identifying the primary focus in patients with metastases of squamous cell carcinoma from an undiagnosed primary focus

Introduction. Squamous cell carcinoma of the oropharynx associated with Human papilloma virus (Hpv) has been identified as a distinct nosological unit among squamous cell carcinoma of the head and neck. This is due to the peculiarities of the disease and localization (the tumor mainly occurs in the palatine or lingual tonsils). primary squamous cell carcinoma of the oropharynx often debuts in the form of cancer metastases from an undiagnosed primary focus.

Aim. To show relationship between presence of the Hpv marker p16 in patients with metastases from an undiagnosed primary focus with primary squamous cell carcinoma of the oropharynx.

Materials and methods. The retrospective study included 151 patients with cervical lymph node metastases from an undiagnosed primary focus, treated from 2014 to 2024 in the Oncology Department of Surgical methods of Treatment No. 10 of the N. N. Blokhin National medical Center of Oncology, 83 of whom were found to have p16 – a surrogate marker of Hpv.

Results. The findings suggest a strong relationship between the presence of Hpv in the metastatic focus and oropharyngeal squamous cell carcinoma. The difficulty of identifying the primary focus is most likely due to the small size of this focus and its submucosal location, as well as with early metastasis to the lymph nodes.

Conclusion. In order not to miss clinically latent squamous cell carcinoma of the oropharynx, interdisciplinary collaboration and conduct of thorough immunohistological study, especially a surrogate marker test for Hpv p16, are needed.