Oropharyngeal cancer

Human papillomavirus (HPV) infection is strongly implicated in the majority of oropharyngeal carcinomas in developed countries. Tobacco and alcohol use are known risk factors in cases not driven by HPV. In medium and low human development index countries, betel nut chewing is also associated with oropharyngeal cancer.

Signs of oropharyngeal cancer at the primary site in the oropharynx include sore throat, referred oral pain, dysphagia, and trismus. Unintentional weight loss and neck mass can be the first signs of otherwise asymptomatic oropharyngeal cancer. In HPV-associated oropharyngeal cancer, patients are often asymptomatic at the primary site, and a neck mass is the most common presenting symptom.

Patients should be referred to an ear, nose, and throat surgeon for biopsy and histological diagnosis.

Diagnosis is made through biopsy of the primary tumour or ultrasound-guided fine needle aspiration cytology of a metastatic lymph node. Staging is through computed tomography (CT) scan or magnetic resonance imaging of the head and neck with contrast, positron emission tomography (PET) or PET-CT, and nasolaryngoscopy. Triple endoscopy with the addition of oesophagoscopy and bronchoscopy is reserved only for patients with active risk factors such as tobacco and alcohol use, as the risk of a synchronous second primary cancer in HPV-associated oropharyngeal cancer is very low.

Treatment regimens vary depending on the stage of the cancer and may involve surgery, radiotherapy, chemotherapy, and/or immunotherapy. Employment of multimodality therapy is common in the treatment of oropharyngeal cancer. Patients should be managed in specialised head and neck centres by a multidisciplinary team to optimise oncological and functional outcomes.

Oropharyngeal cancer is predominantly (90%) a squamous cell carcinoma arising from the subsites of the oropharynx: the base of the tongue, soft palate, palatine tonsillar fossa and pillars, and lateral and posterior pharyngeal wall.[1]El-Naggar AK, Chan JKC, Grandis JR, et al. eds. WHO classification of head and neck tumours. WHO classification of tumours, 4th ed. Vol 9. IARC Press; 2017.​ Non-epithelial tumours, such as minor salivary gland carcinomas, lymphoma, and sarcoma, are possible but less common. They should remain a part of the differential diagnosis until histological confirmation of exact pathology. Lymph node involvement can be observed in the majority of patients, particularly those with human papillomavirus associated oropharyngeal cancer.[2]National Comprehensive Cancer Network. NCCN clinical practice guidelines in oncology: head and neck cancers [internet publication]. https://www.nccn.org/professionals/physician_gls/default.aspx