Detection of Occult Recurrence Using Circulating HPV Tumor DNA Among Patients Treated for HPV-driven Oropharyngeal Squamous Cell Carcinoma

Current perspectives on recurrent HPV-mediated oropharyngeal cancer

In the recent years, the prevalence of HPV-positive oropharyngeal squamous cell carcinoma (OPSCC) has increased significantly. Currently, nearly 80-90% of all oropharynx tumors are HPV-positive. In addition, it is now recognized that HPV-positive tumor status is associated with good prognosis and improved response to chemoradiation. However, within this setting, there are still patients with HPV-positive OPSCC who will experience recurrence. With the increasing incidence of HPV-mediated OPSCC, recurrent HPV disease is also becoming more prevalent and there is an increasing need to understand the unique presentation and treatment of recurrent HPV-mediated disease. In this review, we will discuss epidemiology of recurrent HPV-positive OPSCC, role of surgical salvage, re-irradiation, and the role of upcoming novel treatments and immunotherapy. Historically, recurrent oropharyngeal disease has been associated with poor prognosis and high morbidity. However, recent advances have transformed the landscape for salvage treatment of HPV-mediated OPSCC. Liquid biomarkers offer potential for early detection of recurrence, robotic techniques may reduce morbidity of surgical salvage, improvements in re-irradiation approaches reduce toxicities, and novel immune based therapies on the horizon are offering promising results. These advances combined with the improved prognosis of HPV-positive disease offer to transform our approach to recurrent disease of the oropharynx.

Programmed cell death protein 1 axis blockade in locally advanced squamous cell carcinoma of the head and neck: Neoadjuvant and adjuvant approaches

Immunotherapy and in particular programmed cell death protein 1 (PD-1) inhibitors have been applied not only in the management of recurrent or metastatic disease but also as component of potentially curative treatment for many solid tumors. The incorporation of immunotherapy as neoadjuvant and /or adjuvant therapy in the treatment paradigm of locally advanced squamous cell carcinoma of the head and neck (SCCHN) is appealing with the goals of enhancing antitumor efficacy and, at the same time, reduce toxicity. This review analyzes the rationale for employing immunotherapy in the neoadjuvant and adjuvant settings, reviews the results of relevant clinical trials, and examines the potential benefits and caveats of neoadjuvant and/or adjuvant approaches in patients with SCCHN.

The Promise of Circulating Tumor DNA in Head and Neck Cancer

As the seventh most common cancer globally, head and neck cancers (HNC) exert considerable disease burden, with an estimated 277,597 deaths worldwide in 2020 alone. Traditional risk factors for HNC include tobacco, alcohol, and betel nut; more recently, human papillomavirus has emerged as a distinct driver of disease. Currently, limitations of cancer screening and surveillance methods often lead to identifying HNC in more advanced stages, with associated poor outcomes. Liquid biopsies, in particular circulating tumor DNA (ctDNA), offer the potential for enhancing screening, early diagnosis, and surveillance in HNC patients, with potential improvements in HNC patient outcomes. In this review, we examine current methodologies for detecting ctDNA and highlight current research illustrating viral and non-viral ctDNA biomarker utilities in HNC screening, diagnosis, treatment response, and prognosis. We also summarize current challenges and future directions for ctDNA testing in HNC patients.