Oropharyngeal cancer, also known as oropharyngeal squamous cell carcinoma and tonsil cancer, is a disease in which abnormal cells with the potential to both grow locally and spread to other parts of the body are found in the oral cavity, in the tissue of the part of the throat (oropharynx) that includes the base of the tongue, the tonsils, the soft palate, and the walls of the pharynx. The two types of oropharyngeal cancers are HPV-positive oropharyngeal cancer, which is caused by an oral human papillomavirus infection; and HPV-negative oropharyngeal cancer, which is linked to use of alcohol, tobacco, or both. Oropharyngeal cancer is diagnosed by biopsy of observed abnormal tissue in the throat. Oropharyngeal cancer is staged according to the appearance of the abnormal cells on the biopsy coupled with the dimensions and the extent of the abnormal cells found. Treatment is with surgery, chemotherapy, or radiation therapy; or some combination of those treatments.

Signs and symptoms

The signs and symptoms of oropharyngeal cancer may include:

Risk factors

The risk factors that can increase the risk of developing oropharyngeal cancer are:

Major

Minor

Precancerous lesions

High-risk

Medium-risk

Low-risk

Pathophysiology

The cancer can spread three ways:

Diagnosis

Diagnosis is by biopsy of observed abnormal tissue in the oropharynx.

Stages

The National Cancer Institute (2016) provides the following definition:

Stage 0 (carcinoma in situ)

Abnormal cells are found in the lining of the oropharynx. These may become cancer and spread into nearby normal tissue.

Stage 1

Cancer has formed and is 20 mm or smaller and has not spread outside the oropharynx.

Stage 2

Cancer has formed and is larger than 20 mm, but not larger than 40 mm. Also, it has not yet spread outside the oropharynx.

Stage 3

Stage 4A

Stage 4B

Stage 4C

Cancer has spread to other parts of the body; the tumor may be any size and may have spread to lymph nodes.

Prevention

Regarding the primary prevention of HPV-positive oropharyngeal cancer, HPV vaccines show more than 90% efficacy in preventing vaccine-type HPV infections and their correlated anogenital precancerous lesions. A research conducted in 2017 demonstrated that HPV vaccination induces HPV antibodies levels at the oral cavity that correlate with circulating levels. Regarding the primary prevention of HPV-positive oropharyngeal cancer, safe oral sex habits should be advised (see Sex education). Regarding the primary prevention of HPV-negative oropharyngeal cancer, educating people on the risks of chewing betel quid, alcohol use, and tobacco smoking is of the prime importance in the control and prevention of oropharyngeal cancers.

Prognosis

People with HPV-positive oropharyngeal cancer tend to have higher survival rates. However, HPV is tested for by the presence of the biomarker p16, which normally increases in the presence of HPV. Some people can have elevated levels of p16 but test negative for HPV and vice versa. This is known as discordant cancer. The five-year survival for people who test positive for HPV and p16 is 81%, for discordant cancer it is 53 – 55%, and 40% for those who test negative for p16 and HPV. The prognosis for people with oropharyngeal cancer depends on the age and health of the person and the stage of the disease. It is important for people with oropharyngeal cancer to have follow-up exams for the rest of their lives, as cancer can occur in nearby areas. In addition, it is important to eliminate risk factors such as smoking and drinking alcohol, which increase the risk for second cancers.

Management

Traditionally, oropharyngeal cancer has been managed through combination of surgery and radiotherapy. Other treatments have been developed including a combination of surgery, radiotherapy, chemotherapy and immunotherapy, but with limited improvement in survival rates. Studies comparing different combinations of treatment on patient outcomes have shown insufficient evidence that any treatment combination is superior to others.

Society and culture