Dr Sun on the Importance of Biomarker Testing in Head and Neck Cancers

“Head and neck cancer actually encompasses a number of diverse malignancies, and in many of these cancers, biomarkers are fundamentally necessary to help us figure out what cancer we’re [managing] and how to make treatment decisions.”

Fangdi Sun, MD, an assistant professor of medicine (oncology) at Stanford University, emphasized the critical role of biomarkers in navigating the complexity of the diverse malignancies that comprise the head and neck cancer umbrella.

Sun highlighted that identifying specific biomarkers is no longer optional but fundamentally necessary to differentiate between various types of head and neck cancer and to guide informed treatment decisions. Sun observed that a wide array of distinct diseases fall under the category of head and neck cancer, each requiring a tailored treatment approach. For instance, in advanced salivary gland malignancies, the application of next-generation sequencing (NGS) is both diagnostically and therapeutically useful, she said. Sun pointed out that characteristic molecular findings—such as MYB fusions in adenoid cystic carcinoma or NTRK fusions in secretory carcinoma—are essential for confirming a diagnosis. Furthermore, these biomarkers can reveal targetable vulnerabilities, allowing for the off-label use of existing drugs to treat androgen receptor or HER2 expression, which are commonly found in salivary ductal carcinomas, according to Sun.

Regarding head and neck squamous cell carcinoma, which spans sites from the oral cavity to the hypopharynx, Sun stressed the mandatory nature of biomarker testing, particularly for oropharyngeal primary sites. Sun noted that oncologists must determine whether a tumor is HPV associated using p16 immunohistochemistry as a proxy, or through direct high-risk HPV in situ hybridization (ISH). This distinction is vital because the patient characteristics and prognostic outlooks for HPV-positive vs HPV-negative tumors are different, she stated. Similarly, for nasopharyngeal cancers, Sun advocated for testing for EBV via EBER ISH to ensure diagnostic accuracy, especially in non-endemic regions for HPV-related disease, such as the United States.

Finally, Sun addressed the diagnostic challenge of identifying the primary source of squamous cell carcinoma when it is isolated to a lymph node. In such cases, Sun highlighted the use of NGS or tumor mutational burden to identify signatures of UV-induced damage, which helps oncologists distinguish between cutaneous and mucosal primary tumor sites. Sun concluded that because diagnosis is so inextricably tied to treatment, a deep molecular understanding of the disease is the only way to provide effective, modern care.

Check out the OncLive Biomarker Consortium site for more biomarker insights in head and neck cancer and beyond!