What is Head and Neck Cancer?

Head and neck cancer is the term given to a variety of malignant tumours that occur in the head and neck region.
have been divided into the following sites:



Larynx (C32):

• There are three main parts of the larynx; the glottis (middle section of the larynx where the vocal chords are), the supraglottis (tissue above the glottis), and the subglottis (tissue below the glottis).
• Approximately 95% of laryngeal cancers are squamous cell carcinomas.
• Other cancers include verrucous carcinomas, sarcomas, adenocarcinomas and neuroendocrine tumours

Oral cavity (C00-C06):

• The oral cavity comprises the tongue, hard palate (roof of mouth), the floor of the mouth, the inner lining of the lips and cheeks (buccal mucosa), the alveolar ridge, and the retromolar trigone.
• These cancers are squamous cell carcinomas.

Pharynx (C09-C14):

• The pharynx comprises:
• the hypopharynx (bottom part of the throat),
• the nasopharynx (upper part of the throat)
• the oropharynx (part of the throat at the back of the mouth including the base of the:tongue,tonsil, tonsillar pillar and the soft palate).

Salivary gland (C07-C08):

• Salivary gland tumours account for approximately 5% of all head and neck cancers.
• The major salivary glands are

• the parotids,
• submandibulars and
• sublingual.

• The minor glands are located throughout the upper aero-digestive tract.

• Approximately 90% of salivary gland tumours occur in the parotid gland. These tumours include:
  

• adenocarcinoma,
• epidermoid carcinoma,
• acinic cell carcinoma,
• mucoepidermoid carcinoma and
  
• adenoid cystic carcinoma.

Thyroid gland (C73):

• The thyroid is a small gland in thefront of the neck just below the larynx that produces the two main hormones,

• thyroxine
• triiodothyronine.

• Different types of thyroid cancer develop at different ages.

• Papillary (accounting for approximately 60%),
• follicular (15%) and
• medullary (5-10%) thyroid cancer, occur mainly in younger and middle aged people.
• Anaplastic thyroid cancer (accounting for approximately 15%) tends to develop in older people.

Other:

• cancers of the ear and nose (C30)
• and accessory sinuses (C31). These are mainly squamous cell carcinomas.

Cancers of the external skin (C43 & C44) and

• mucosal surfaces of the nose and paranasal sinuses include :
• basal cell carcinoma,
• squamous cell carcinoma and
• malignant melanoma.

Symptoms

• Most head and neck cancers are asymptomatic in their early stages.
• Symptoms may vary according to the site of the tumour,

Symptoms of head and neck cancer include an :

• ulcer orsore throat that does not heal,
• difficulty or pain in swallowing or chewing,
• swelling or lump in the mouth or neck,
• breathing trouble,
• voice changes,
• a persistent blocked nose or earache.
• the lining of the mouth or on the tongue as white patches (leukoplakia) or red patches (erythroplakia).
• The usual presentation of thyroid cancer is that of a palpable mass or a hoarse voice.

Diagnosis

• A full ear nose and throat (ENT) examination is necessary to examine
• A biopsy from the head and neck region may be taken directly or through an
• endoscope, and a fine needle aspiration (FNA) biopsy may be performed

Imaging techniques such as computerised tomography (CT),

• magnetic resonance imaging (MRI),
• x-rays, ultrasound, thyroid scan (isotope/gamma camera scan) and bone scans may be performed to outline the full
• extent of the tumour, assist staging and identify any metastasis or impalpable neck
• nodes.

Risk Factors

• Smoking & Alcohol - Smoking and alcohol consumption act separately and synergistically.
• Tobacco is the main factor associated with the development of head and neck cancers with over 90% of patients having a history of smoking.
• Together, smoking and excessive alcohol intake increase the risk of head and neck cancers by up to 15 times.
• Snuff and chewing tobacco or
• betel nuts are also implicated
• Age & Sex - Head and neck cancers are more common in men than in women (2:1 ratio) and occur mainly in middle-aged andolder people.

Conditions & Viruses

• Oral lesions and conditions may indicate a cancerous or pre-cancerous condition.
• leukoplakia (white patches) and erythroplakia (red patches) which are mainly found in people who smoke or chew tobacco.
• Leukoplakia is more common, but less likely to progress to malignancy than erythroplakia.
• Human papillomavirus
• (HPV) has been detected in squamous cell carcinomas of the head and neck,
• and Epstein-Barr virus (EBV) is well recognised in association with nasopharyngeal carcinoma.

Other Factors - A deficient diet is thought to predispose towards the development of oral cancers, particularly diets deficient in

• vitamin A, C, E, iron and selenium.
• There is also a recognised association between the furniture industry (wood dust) and
• malignancies of the paranasal sinuses. Exposure to polycyclic hydrocarbons, as in the textile industry, has been linked to
• tumours of the oral cavity.

The cancer is also observed in survivors of atomic explosions or accidents.
Exposure to the sun is an important risk factor for cancers of the lips and skin.

Treatment

The treatment of head and neck cancer is dependent on factors relating to

• the disease site(s),
• stage,
• anatomical accessibility
• and the patients general health.

Surgery and radiotherapy are the main forms of curative treatment for head and neck cancer.

• In general, small primary lesions are best treated with surgery or radiotherapy alone, while advanced lesions are more likely to
• need both surgery and radiotherapy.

Surgery

• Surgical resection aims to remove the whole tumour with a margin adequate to allow for the removal of surrounding microscopic invasion.
• Laser surgery may be used to remove small tumours in the oral cavity and the larynx.
• Surgical excision is preferable for advanced tumours invading bone or cartilage, as radiotherapy may cause osteoradionecrosis.
• neck dissection may be performed depending on the site, stage and location of the tumour.
• The degree of dissection will be determined by the risk of nodal involvement and may involve the removal of ipsilateral lymph nodes,
• The internal jugular vein,
• the accessory nerve and
• sternocleidomastoid muscle.

Radiotherapy

• Smaller tumours may be initially treated with radiotherapy, reserving surgery for local recurrence.
• Radiotherapy has the advantage of preserving the voice, speech, swallowing and tissues that surgery would sacrifice and is therefore better for smaller tumours.
• Radiotherapy may be used if an excision has been incomplete or if there is recurrence after surgery.

Radiotherapy is inappropriate for treating:

• locally advanced or bulky disease,
• can be used after surgery
• the palliative setting, where bleeding or ulceration are problematic symptoms.

For papillary or follicular thyroid cancer that has recurred or spread, or after treatment with surgery, targeted radiotherapy with a radioactive form of Iodine (I131) is used to kill the cancer
cells.
Anaplastic thyroid cancer may be treated with external beam radiotherapy if surgery cannot remove the tumour.


Most laryngeal cancers present relatively early and radiotherapy confined to the larynx plus a margin may be the preferred
initial treatment.
Larger advanced tumours may require a total laryngectomy (removal of the larynx), with postoperative radiotherapy.


Unlike other head and neck cancers, the primary treatment for nasopharyngeal carcinoma is radiotherapy, often
in combination with chemotherapy.

Chemotherapy

Chemotherapy is generally not used for small lesions, but may be used to:

1. eradicate
2. control early metastasis,
3. shrink a tumour before surgery or radiotherapy,
4. be used as palliation.