Laryngeal Cancer

Question 1

Why types of cancers are most laryngeal cancers?

Answer 1

Squamous cell carcinomas (SCC)

Question 2

Describe the 3 main areas of the larynx.

Answer 2

Supraglottis: above the level of the vocal cords
Glottis: at the level of the vocal cords and the
Subglottis: below the level of the vocal cords

Question 3

Describe the anatomical boarders of the larynx.

Answer 3

Anteriorly the larynx is bounded by the:

Infrahyoid or strap muscles (sternohyoid muscle, sternothyroid muscle, thyrohyoid muscle, omohyoid muscle)
Thyroid gland
Parathyroid glands

Laterally the larynx is bounded by the:

Common carotid artery
Internal jugular vein
Vagus nerve
Recurrent laryngeal nerve

Posteriorly the larynx is bounded by the oesophagus.

Question 4

Describe the blood supply to the larynx.

Answer 4

Arterial blood is supplied via the superior laryngeal artery (a branch of the superior thyroid artery) and the inferior laryngeal artery. Venous drainage is similarly via the superior and inferior laryngeal veins.

Question 5

Describe the innervation of the larynx.

Answer 5

The main nerves supplying the larynx are the superior laryngeal nerve and the recurrent laryngeal nerve.

Superior laryngeal nerve (external branch):

Cricothyroid muscle
Recurrent laryngeal nerve (inferior branch):

Posterior cricoarytenoid muscle
Lateral cricoarytenoid muscle
Transverse and oblique arytenoid muscles

Question 6

Name some risk factors of developing laryngeal cancers.

Answer 6

Smoking: over 80% of head and neck cancers are thought to be caused by tobacco, alcohol or a combination of both.
Alcohol: whilst alcohol is not directly carcinogenic, it is metabolised by the liver into acetaldehyde which is highly mutagenic.
Age: the incidence increases with age and it is most common in the 5th and 7th decade of life.
Poor oral hygiene: this has also been shown to play a contributing factor in the development of head and neck cancers.
Human papillomavirus (HPV) infection: currently, at least 2.4% of cases of laryngeal malignancy are attributable to HPV infection and this number is likely to rise.

Question 7

Describe how patients with laryngeal cancer would present.

Answer 7

Clinical features can vary depending on the anatomical location of laryngeal cancer.

Glottic tumours are more likely to present with hoarseness and stridor, and patients will therefore present earlier. Tumours at other sites can be silent until they are at a more advanced stage.

Some patients will present with enlarged neck nodes only.

Question 8

How are head and neck cancers staged?

Answer 8

TNM Classification

Question 9

Describe how early stage laryngeal cancer would be managed.

Answer 9

transoral resection of the primary lesion or primary radiotherapy.

Question 10

Describe how advanced stage laryngeal cancer would be managed.

Answer 10

Advanced stage malignancy can be managed with organ-preserving approaches in the form of curative primary chemo-radiotherapy.