- These are squamous cell cancers (i.e. derived from the mucosal epithelium). Unfortunately, they usually present late and are poorly differentiated so have a poorer prognosis compared to laryngeal cancer (5-year survival around 30%).
- They are relatively rare compared to laryngeal cancer.
- The most common site for a pharyngeal cancer is in the pyriform sinus (65-85%), lateral pharyngeal wall, posterior pharyngeal wall (10-15%) or postcricoid area (5-15%).
Smoking and alcohol excess are synergistic risk factors. Rarely GORD and acid reflux are risk factors.
Tumours need to be quite large to cause symptoms:
- occasionally aspiration
- weight loss can often be secondary to this and not actual cancer
- chronic sore throat
- unilateral and well localised
- unresponsive to antibiotic treatment
- either involvement of the recurrent laryngeal nerve (CN X that runs deep to the anterior wall of the pyriform sinus) or direct invasion into the larynx
- foreign body sensation
- globus hystericus
- Referred otalgia
- via Arnold’s nerve- CN X
- neck lump
- NB more commonly a lymph node metastasis than the actual cancer
- Haemoptysis (rarer)
- Halitosis (due to necrotic tumours- also rarer)
- On endoscopy, there may be subtle signs e.g.
- salivary pooling
- asymmetrical tonsils
or the mass may be seen directly.
- Trismus (inability to fully open mouth) may suggest pterygoid involvement
NB Make sure to do a full respiratory/CVS/abdo exam to check for associated problems (pharyngeal cancer may be a met of a primary lung cancer or it may be a primary with mets in the liver).
FBC may show anaemia of chronic disease. CT of the head and neck is the key investigation. Triple endoscopy (laryngoscopy, bronchoscopy and oesophagoscopy) is often used for biopsy and further investigation.
Most tumours will have a high TNM score and so treatment will be a mix of surgery (more for symptomatic treatment), radio- and chemotherapy.