What should all oropharyngeal cancers be tested for?

Testing for p16 overexpression is critical in all oropharyngeal cancers as it serves as a biomarker for identifying human papillomavirus (HPV)-associated malignancies. HPV-positive oropharyngeal cancers have a distinct etiology compared to HPV-negative cancers, often linked to tobacco and alcohol use. These HPV-positive cancers typically exhibit p16 overexpression due to the action of the viral E7 protein, which inactivates the pRb protein, resulting in increased levels of p16.

The presence of p16 overexpression in tumors is a strong indicator of HPV involvement and has implications for prognosis and treatment. Patients with HPV-positive oropharyngeal cancers generally have better outcomes and may be eligible for less aggressive treatment protocols. Thus, testing for p16 overexpression is not only essential for diagnosis but also plays a crucial role in guiding clinical management and therapeutic decisions.

In contrast, while there are testing protocols for other biomarkers such as p53 mutations, HER2/neu amplification, and EGFR expression, these do not hold the same universal significance for oropharyngeal tumors as the presence of p16. The pivotal role of p16 in the context of HPV-related oropharyngeal cancer makes it a standard