Oropharyngeal cancer (OPC) is one of the most common head and neck squamous cell carcinomas globally (84). OPC includes cancer of the tonsils, tonsillar crypt and pillars, base of tongue and oropharynx. Traditional risk factors are smoking and excessive alcohol use (85) but in the past two decades, there is a rise in HPV-associated OPC in developed countries among non-smoking individuals, aged 35-55 years (86, 87). More males are affected compared to females with a ratio of approximately 3:1 (88, 89). HPV causes approximately 70% of OPC in the United States (90). In particular, HPV-16 is associated with 90% of HPV-associated OPC (90). Compared to individuals with HPV-negative OPC, those with HPV-associated OPC are younger with a median age of 54 years, have less exposure to tobacco and alcohol, and have better five-year survival (82% vs. 35% in HPV-negative cancers) (91, 92).
There is currently no consensus on screening for OPC and, consequently, precancerous lesion may not recognised. Salivary oral rinse with or without abrasion may be used to detect HPV DNA (93). However, the presence of HPV does not equate with definite risk of progression to cancer. HPV is found in the oropharynx of healthy adults and the vast majority will clear the virus naturally and without any symptoms. Further, oral HPV infection may lie dormant for many years (94). The United States National Health and Nutrition Examination Survey (NHANES) estimates that prevalence of any HPV in adults aged 18 to 69 years was 7.3% (95).
There are no definitive symptoms pathognomonic for OPC. Potential symptoms may include an unhealing sore or ulcer, discoloration in the soft tissues, difficult or painful swallowing, persistent sore throat or hoarse voice, earache, swollen cervical lymph nodes, and a swelling or lump. Individuals may also have loss of appetite and/or weight, and general malaise.
Examination under anaesthesia is recommended but not mandatory. Histologic diagnosis from a biopsy of the tissue sample is needed, especially for those undergoing curative treatments. HPV testing is recommended for all OPC. Staging investigations includes MRI or CT scan.
Radiotherapy is the mainstay of treatment though the stage of cancer will determine the optimal modality: chemotherapy, radiotherapy and/or surgical resection. In recent years, use of minimally invasive surgery has resulted in good survival rates (96, 97). More details of management guidelines can be found elsewhere (98).