Current and Emerging Protein Biomarkers for the Diagnosis and Prognosis of Head and Neck Cancer

Head and neck cancer represents a heterogeneous group of malignancies. Oral squamous cell carcinoma (OSCC) is the most prevalent form of head and neck cancer, with a rising incidence in recent years. Risk factors for developing OSCC include exposure to carcinogens, such as alcohol and tobacco products, that can lead to molecular alterations in the oral mucosa and progression from premalignant lesions to invasive phenotypes. Despite the relative curative potential of localized OSCC, the overall prognosis of OSCC has not significantly improved for decades due to a frequently delayed diagnosis and limited targeted treatment options. There remains a need to better characterize the molecular biomarkers of OSCC progression, especially in dysplastic mucosal lesions, before their malignant transformation. In this review, we discuss several molecular biomarkers highly implicated in OSCC tumorigenesis that have demonstrated correlation with clinicopathological parameters and clinical outcomes. These biomarkers are typically involved in vital pathways of carcinogenesis, including cell cycle control, growth factor signaling, and stress responses. They include ubiquitous cancer biomarkers such as p53 and PTEN, as well as those more specific to OSCC, such as DJ-1 and Cornulin. Collectively, we envision that a diverse panel of these biomarkers can provide the greatest clinical benefit in enhancing early detection and prognostic accuracy, while some individual biomarkers may also serve as therapeutic targets for personalized approaches to head and neck cancers.