Laryngeal cancer
Definition
Cancer of the throat.
Pathophysiology
Laryngeal cancers are almost exclusively squamous cell carcinomas. They are classified according to anatomy:
- Supraglottic - including the epiglottis, aryepiglottic folds, arytenoids, false cords... basically everything above the vocal cords
- Glottic - the vocal cords
- Subglottis - below the vocal cords
Epidemiology
Glottic is the most common accounting for 60% of cases of laryngeal cancer. Supraglottic accounts for a further 30% and subglottic accounting for the remaining 10%.
Risk Factors
- Smoking - by far the biggest risk factor. Really big. 10x that of non-smokers with pipe or cigar smoking actually worse than cigarettes
- Alcohol & smoking - there is a synergistic effect i.e. the risk is far more than simply adding the risk of smoking and alcohol together
- Diet
- Occupational exposure to carcinogens - asbestos, formaldehyde, nickel, sulphufric acid in particular
- HPV - implicated in upper airway tract cancer
Clinical Features
Glottic cancers mainly present with hoarseness (90%). The other two big symptoms are pain on swallowing (30-40%) and dysphagia (30%).
Supraglottic cancers tend to present late because there's a lot of space for them to take up before they start having an effect. Muffling of the voice, rarely hoarseness can present. Dysphagia that is painful occurs with aryepiglottic tumours. Metastatic neck nodes are occasionally the presenting feature.
Subglottic usually present with respiratory distress due to obstruction. If they expand upwards, they can present with hoarseness.
Investigations
Diagnosis and staging are done through a combination of CXR, CT, MRI and bronchoscopy with tissue biopsy.
Staging
- T1S - carcinoma in situ
- T1 - one anatomical site
- T2 - two sites, mobile vocal cords
- T3 - fixed vocal cords
- T4 - outside of larynx
Management
Pretty standard really - radiotherapy or surgery which can be a total laryngectomy if necessary.