Next Lesson - Imaging of the Head and Neck
Core
Introduction to Head and Neck Cancers
Head and neck cancer is a collective term for malignancies of the oral cavity (mouth), nasal cavity, paranasal sinuses (air-filled spaces in the bones around the nose), pharynx (throat), larynx (voice box) or salivary glands.
The majority (around 90%) of head and neck cancers are squamous cell carcinomas (HNSCCs), which start in the flat cells lining the mouth, nose and throat. Other rarer types include lymphomas, blastomas (tumours of immature cells), sarcomas and neuroendocrine tumours (tumours of cells with features of both nerve cells and hormone-producing cells).
Risk factors for head and neck cancer include the following. Smoking and alcohol are the most important, and the risk is highest when they are combined. Some of the other factors are linked to one site only.
- Smoking
- Alcohol
- Betel nut chewing
- Human papillomavirus (HPV) infection, mainly type 16 (linked to oropharyngeal cancer, which starts in the part of the throat behind the mouth, usually the tonsils or the base of the tongue)
- Epstein-Barr virus (EBV) infection (linked to nasopharyngeal cancer, in the upper throat behind the nose)
- Wood dust inhalation
The presentation of HNSCCs varies depending on the site of the tumour. However, constitutional symptoms (symptoms affecting the whole body) such as weight loss may be present in more advanced disease, as may lymphadenopathy (enlarged lymph nodes).
Red flags are features that should prompt you to consider a suspected cancer pathway referral, which is an urgent referral to a specialist team. This is usually to ear, nose and throat (ENT) surgeons, or to oral and maxillofacial surgeons, who treat the mouth, jaws and face. Mouth lesions are often assessed first by a dentist. Examples from NICE guideline NG12 include:
- Persistent, unexplained hoarseness of voice in people aged 45 and over
- Persistent, unexplained neck lump, or an unexplained neck lump in people aged 45 and over
- Mass on the lip or oral cavity
- Erythroplakia or erythroleukoplakia
- Unexplained oral ulceration lasting longer than 3 weeks
Oral cancer can affect any part of the oral cavity, including the lip and tongue.
Patients may present with a mouth ulcer that does not heal, a lump in the oral cavity or a red or white patch. The lesion may be painless, or it can be painful and bleed.
Oral cancer is associated with certain premalignant lesions (abnormal areas of the lining that may turn into cancer) such as leukoplakia (white patches that do not rub off, unlike thrush, a fungal infection), erythroplakia (red patches) and erythroleukoplakia (a combination of both). Erythroplakia is classically thought to have the highest risk of becoming cancer.
Treatment is commonly with surgery. More advanced disease may require chemotherapy and/or radiotherapy.
Image - Leukoplakia of the lower lip and gum
Public Domain Source by National Cancer Institute [Public domain]
Pharyngeal cancer (cancer of the throat) may involve the nasopharynx (the upper throat, behind the nose), the oropharynx (the middle throat, behind the mouth) or the hypopharynx (the lower throat, behind the larynx, also called the laryngopharynx).
Many patients present with advanced disease. Symptoms include odynophagia (painful swallowing), dysphagia (difficulty swallowing) and referred otalgia (ear pain, felt in the ear although the problem is in the throat). A neck lump due to cervical lymphadenopathy (enlarged lymph nodes in the neck) may also be present. It is often the first sign of nasopharyngeal cancer, and it is the most common symptom of oropharyngeal cancer.
Treatment depends on which part of the pharynx is affected. Nasopharyngeal cancer of stage 2 and above is treated with radiotherapy plus chemotherapy (chemoradiotherapy). Early oropharyngeal cancer can be treated with transoral surgery (surgery through the mouth) or with radiotherapy. Larger tumours, and those that have spread to lymph nodes, are treated with radiotherapy combined with chemotherapy or surgery. Neck dissection (surgery to remove lymph nodes from the neck) is not needed after chemoradiotherapy if scans show no residual disease, but is used if disease persists.
Laryngeal cancer may involve the supraglottis (above the vocal cords), glottis (the vocal cords themselves) or subglottis (below the vocal cords).
Hoarseness of voice is one of the most common symptoms of laryngeal cancer. Patients may also present with dysphagia (difficulty swallowing), odynophagia (painful swallowing), persistent cough, stridor (noisy breathing caused by a narrowed airway) and/or referred otalgia (ear pain).
The glottis and supraglottis are the commonest sites. In a recent west of Scotland study, supraglottic cancers (58%) were more common than glottic cancers (33%), the reverse of the position about 20 years earlier. Glottic cancers have a better prognosis. Hoarse voice leads to earlier presentation, and early glottic tumours rarely spread to lymph nodes.
Small tumours can be treated with transoral laser microsurgery (removal with a laser through the mouth) or with radiotherapy. Neck dissection (surgery to remove lymph nodes from the neck) is rarely needed for small glottic tumours, but supraglottic tumours spread to lymph nodes more often. Larger tumours can be treated with chemoradiotherapy (radiotherapy given with chemotherapy), which aims to keep the larynx, or with surgery followed by radiotherapy. The most advanced tumours may need laryngectomy (removal of the larynx) followed by radiotherapy, with or without chemotherapy. Laryngectomy is also used if the cancer returns after chemoradiotherapy.
Patients with an obstructive laryngeal cancer (one that blocks the airway) may need a tracheostomy. This involves making a hole in the anterior (front of the) neck and passing a tracheostomy tube directly into the trachea to allow the patient to breathe.
After a total laryngectomy the patient breathes through a permanent hole in the neck called a stoma, because there is no longer a connection between the mouth, nose and lungs. This is not the same as a tracheostomy, and the difference matters in an airway emergency.
Diagram - Creation of a tracheostomy
Public Domain Source by National Heart Lung and Blood Institute (NIH) [Public domain]
Thyroid cancer is not usually classed as a head and neck cancer, but it is an important differential (one of the possible causes) for a neck lump.
The most common type of thyroid cancer is papillary carcinoma, followed by follicular carcinoma. Both are called differentiated thyroid cancers, because the cancer cells still look like normal thyroid cells. Rarer types include medullary (which can run in families), anaplastic (undifferentiated, so the cells look very unlike normal thyroid cells) and lymphoma.
Image - Histology (microscope appearance) of papillary thyroid carcinoma
Creative commons source by Nephron [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)]
Risk factors include:
- Female sex
- Family history, including inherited syndromes such as Multiple Endocrine Neoplasia (MEN)
- Previous radiotherapy
- Hashimoto’s thyroiditis (an autoimmune condition of the thyroid), which is linked to thyroid lymphoma
Thyroid cancers most commonly present as a palpable neck lump (one you can feel). Thyroid cancer is more likely if there is evidence of rapid growth, tethering (the lump being fixed to the tissue around it), lymphadenopathy, hoarse voice or weight loss. Thyroid tumours very rarely produce thyroid hormone so most patients with thyroid cancer are euthyroid (they have normal thyroid hormone levels). Thyroid function tests (blood tests of thyroid hormone levels) are usually normal, but an abnormal result does not exclude thyroid cancer. For more information, check out our articles on Lymph Nodes and Neck Lumps, and The Thyroid Gland.
Thyroid cancers are diagnosed with ultrasound and Fine Needle Aspiration Cytology (FNAC) to look for malignant cells.
Treatment options for thyroid cancer include:
- Surgery - either hemithyroidectomy (removal of half of the thyroid) or total thyroidectomy (removal of the whole thyroid). Patients without a thyroid gland will require lifelong thyroxine replacement.
- Radioiodine therapy (radioactive iodine, which is taken up by thyroid cells) - in differentiated thyroid cancer, offered after total thyroidectomy to people at higher risk, to destroy any thyroid tissue left behind, including cancer cells. It is not offered for small, low-risk tumours unless there are adverse features or spread.
- Radiotherapy - used in selected cases, usually as adjunct therapy rather than primary treatment.
Reviewed by: Dr. Thomas Burnell and Dr. Marcus Judge
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