Head and neck cancer is a general term encompassing multiple cancers that can develop in the head and neck region. These include cancers of the mouth, tongue, gums and lips (oral cancer), voice box (laryngeal), throat (nasopharyngeal, oropharyngeal, hypopharyngeal), salivary glands, nose and sinuses. Head and neck cancer can present a wide range of symptoms depending on where the cancer developed. These can include an ulcer in the mouth that does not heal, changes in the voice, difficulty swallowing, red or white patches in the mouth, and a neck lump. The majority of head and neck cancer is caused by the use of alcohol or tobacco (including smokeless tobacco). An increasing number of cases are caused by the human papillomavirus (HPV). Other risk factors include the Epstein–Barr virus, chewing betel quid (paan), radiation exposure, poor nutrition and workplace exposure to certain toxic substances. About 90% are pathologically classified as squamous cell cancers. The diagnosis is confirmed by a tissue biopsy. The degree of surrounding tissue invasion and distant spread may be determined by medical imaging and blood tests. Not using tobacco or alcohol can reduce the risk of head and neck cancer. Regular dental examinations may help to identify signs before the cancer develops. The HPV vaccine helps to prevent HPV-related oropharyngeal cancer. Treatment may include a combination of surgery, radiation therapy, chemotherapy, and targeted therapy. In the early stage head and neck cancers are often curable but 50% of people see their doctor when they already have an advanced disease.
Globally, head and neck cancer accounts for 650,000 new cases of cancer and 330,000 deaths annually on average. In 2018, it was the seventh most common cancer worldwide, with 890,000 new cases documented and 450,000 people dying from the disease. The usual age at diagnosis is between 55 and 65 years old. The average 5-year survival following diagnosis in the developed world is 42–64%.
Signs and symptoms Head and neck cancers can cause a broad range of symptoms, many of which occur together. These can be categorised as local (head and neck cancer-specific), general, and gastrointestinal symptoms. Local symptoms include changes in taste and voice, inflammation of the mouth or throat (mucositis), dry mouth (xerostomia), and difficulty swallowing (dysphagia). General symptoms include difficulty sleeping, tiredness, depression, and nerve damage (peripheral neuropathy). Gastrointestinal symptoms are typically nausea and vomiting. Symptoms predominantly include a sore on the face or oral cavity that does not heal, trouble swallowing, or a change in voice. In those with advanced disease, there may be unusual bleeding, facial pain, numbness or swelling, and visible lumps on the outside of the neck or oral cavity. Head and neck cancer often begins with benign signs and symptoms of the disease, like an enlarged lymph node on the outside of the neck, a hoarse-sounding voice, or a progressive worsening cough or sore throat. In the case of head and neck cancer, these symptoms will be notably persistent and become chronic. There may be a lump or a sore in the throat or neck that does not heal or go away. There may be difficulty or pain in swallowing. Speaking may become difficult. There may also be a persistent earache. Other symptoms can include: a lump in the lip, mouth, or gums; ulcers or mouth sores that do not heal; bleeding from the mouth or numbness; bad breath; discolored patches that persist in the mouth; a sore tongue; and slurring of speech if the cancer is affecting the tongue. There may also be congested sinuses, weight loss, and some numbness or paralysis of facial muscles.
Mouth
Oral cancer affects the areas of the mouth, including the inner lip, tongue, floor of the mouth, gums, and hard palate. Cancers of the mouth are strongly associated with tobacco use, especially the use of chewing tobacco or dipping tobacco, as well as heavy alcohol use. Cancers of this region, particularly the tongue, are more frequently treated with surgery than other head and neck cancers. Lip and oral cavity cancers are the most commonly encountered types of head and neck cancer. Surgeries for oral cancers include:
Maxillectomy (can be done with or without orbital exenteration) Mandibulectomy (removal of the lower jaw or part of it) Glossectomy (tongue removal; can be total, hemi, or partial) Radical neck dissection Combinational (e.g., glossectomy and laryngectomy done together). The defect is typically covered or improved by using another part of the body and/or skin grafts and/or wearing a prosthesis.
Nose
Paranasal sinus and nasal cavity cancer affects the nasal cavity and the paranasal sinuses. Most of these cancers are squamous cell carcinomas.
Nasopharynx
Nasopharyngeal cancer arises in the nasopharynx, the region in which the nasal cavities and the Eustachian tubes connect with the upper part of the throat. While some nasopharyngeal cancers are biologically similar to the common head and neck cancers, "poorly differentiated" nasopharyngeal carcinoma is lymphoepithelioma, which is distinct in its epidemiology, biology, clinical behavior, and treatment and is treated as a separate disease by many experts.
Throat
Most oropharyngeal cancers begin in the oropharynx (throat), the middle part of the throat that includes the soft palate, the base of the tongue, and the tonsils. Cancers of the tonsils are more strongly associated with human papillomavirus infection than are cancers of other regions of the head and neck. HPV-positive oropharyngeal cancer generally has a better outcome than HPV-negative disease, with a 54% better survival rate, but this advantage for HPV-associated cancer applies only to oropharyngeal cancers. People with oropharyngeal carcinomas are at high risk of developing a second primary head and neck cancer.
Hypopharynx
The hypopharynx includes the pyriform sinuses, the posterior pharyngeal wall, and the postcricoid area. Tumors of the hypopharynx frequently have an advanced stage at diagnosis and have the most adverse prognoses of pharyngeal tumors. They tend to metastasize early due to the extensive lymphatic network around the larynx.
Larynx
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