Advancement in the Oropharyngeal Primary Unknown Cancer Diagnostic and Current Treatments Pathway: A Narrative Review

Objective: The objective of this article is to define a correct diagnostic pathway for oropharyngeal cancer of unknown primary (OPCUP) identification. Background: OPCUP represents one of the most frequent causes of neck metastases onset without the identification of the primary tumor. Therefore, there is a high percentage of late or missing diagnoses, resulting in treatment delay or in a wrong therapeutic process. The up-to-date diagnostic procedures can help us to begin therapies at the right time. Methods: This is a review of the latest articles about diagnostic pathways in the OPCUP. A selection of the references was carried out in PubMed, EMBASE, Cochrane, and CENTRAL electronic databases. Conclusion: The oropharynx represents the most common site of primary unknown head and neck cancer (HNCUP). Recent epidemiologic data reported an increasing incidence of HNCUP related to human papilloma virus positive squamous cell carcinoma. Positron emission tomography combined with computerized tomography scanning or magnetic resonance imaging allows for improving the detection of primary unknown tumors and distant and locoregional metastases. Finally, the introduction of the trans-oral robotic surgical approach has introduced a new role of surgery in the HNCUP diagnosis and treatment. Hence, the new technological improvement allows reaching in most HNCUP patients an early diagnosis, achieving targeted management and better treatment outcomes, as well as decreasing toxicity and the side effects of treatment options.