Pharyngeal Cancer

The pharynx (throat) is a muscular passage lined with mucosa that begins behind the nasal cavity and extends down to the oesophagus (food pipe). Cancers that develop in this area, which is shared by the airway and the digestive tract, are called pharyngeal cancer. Symptoms and treatment differ according to the part of the pharynx in which the tumour is located.

What is pharyngeal cancer?

The great majority of pharyngeal cancers arise from the flat cells that line the inner surface of the pharynx; these tumours are called squamous cell carcinoma. Less often, tumours arising from lymphoid tissue or from the minor salivary glands are seen. The pharynx has three parts, and cancer can develop in any of them:

• Nasopharynx: The upper part, directly behind the nasal cavity.
• Oropharynx: The middle part behind the mouth, which includes the tonsils, the base of the tongue, the soft palate and the back wall of the throat.
• Hypopharynx: The lower part, behind and to the sides of the voice box (larynx), which opens into the oesophagus.

Risk factors

Long-term tobacco and alcohol use, especially in combination, are the best-known risk factors. Some oropharyngeal cancers are linked to the human papillomavirus (HPV), while in nasopharyngeal cancer the Epstein-Barr virus and a family history are more prominent. Dietary habits, long-standing reflux and certain occupational exposures may also contribute. Having these risk factors does not mean cancer will develop; it only increases the likelihood.

Symptoms

Pharyngeal cancer may be silent at first or cause mild complaints resembling an ordinary throat infection. Common symptoms include:

• A persistent sore throat or a feeling of something stuck in the throat
• Difficulty swallowing or pain on swallowing
• Constant earache on the same side
• A change in the voice or a muffled voice
• A painless lump in the neck
• Unexplained weight loss
• In nasopharyngeal tumours, nasal blockage, blood-stained nasal discharge or reduced hearing on one side

Diagnosis

Assessment begins with a detailed history and an ear, nose and throat examination. Because the lower parts of the pharynx cannot be seen directly through the mouth, they are examined with a thin, flexible camera (endoscope). If a suspicious area is seen, a small tissue sample (biopsy) is taken to confirm the diagnosis. Imaging such as computed tomography, magnetic resonance imaging or a PET scan is used to determine the extent of the tumour and the state of the lymph nodes in the neck. This information is brought together to determine the stage of the disease (stage I–IV).

Treatment

The treatment plan depends on the location and stage of the tumour, your general health, and the likelihood of preserving swallowing and speech. The main options are surgery, radiotherapy and chemotherapy, used alone or in combination. A single method may be sufficient for early-stage tumours, while more advanced stages may require a combination of methods. The decision is made jointly by a tumour board made up of doctors from different specialties.

When should you see a doctor?

If you notice a sore throat, difficulty swallowing, earache on one side, a change in your voice or a growing lump in the neck lasting more than a few weeks, you are advised to see an ear, nose and throat specialist. Most of these complaints have benign causes, but early assessment allows a possible tumour to be caught while it is still small.