Larynx

Question 1

The peak incidence of larynx cancer

Answer 1

50-60 years old, more common in men than women

Question 2

Location of larynx cancer

Answer 2

65% occur in the true glottis
30% in the supraglottis
5% in the subglottis

Question 3

Risk factors of larynx cancer

Answer 3

Usually associated with smoking (10 fold risk) and alcohol consumption
It maybe due to occupational exposure
Or use of voice extensively

Question 4

Most common pathology of larynx cancer

Answer 4

SCC is the most dominant

Question 5

Signs and symptoms of larynx cancer

Answer 5

True glottic tumours affect speech (hoarseness)

Advanced tumours may cause difficulty breathing and pain

Question 6

The spread of larynx cancer

Answer 6

Lymph node spread only if an extensive disease that is creeping superiorly into the supraglottic region

Question 7

T1 stage larynx cancer (glottis)

Answer 7

Tumour limited to vocal cords with normal mobility
T1a: tumour limited to one vocal cord
T1a: tumour involves both vocal cords

Question 8

T2 stage larynx cancer (glottis)

Answer 8

Tumour extends to supraglottis or subglottis with impaired vocal cord mobility

Question 9

T3 stage larynx cancer (glottis)

Answer 9

Tumour limited to the larynx with vocal cord fixation OR invasion of paraglottic space OR inner cortex of thyroid cartilage

Question 10

T4 stage larynx (glottis)

Answer 10

T4a: moderately advanced local disease
T4b: very advanced local disease

Question 11

T1 stage larynx (supraglottis)

Answer 11

T1: the tumour is limited to one subsite of the supraglottis with normal vocal cord mobility

Question 12

T2 stage larynx (supraglottis)

Answer 12

Tumour invades mucosa or more than one adjacent structure without fixation of the larynx.

Question 13

T3 stage laynx (supraglottis)

Answer 13

Limited to larynx with vocal cord fixation or invades post cricoid cartilage, pre-epiglottic space or para-glottic space

Question 14

T4 stage larynx (supraglottis)

Answer 14

T4a: moderately advanced local disease
T4b: very advanced local disease

Question 15

T1 stage larynx (subglottis)

Answer 15

Limited to subglottis

Question 16

T2 stage larynx (subglottis)

Answer 16

Extends to vocal cords with normal or impaired mobility

Question 17

T3 stage larynx (subglottis)

Answer 17

limited to larynx with vocal cord fixation

Question 18

T4 stage larynx (subglottis)

Answer 18

T4a: moderately advanced local disease
T4b: very advanced local disease

Question 19

N1 stage head and neck (except nasopharynx, oropharynx, hypopharynx, and thyroid)

Answer 19

Single ipsilateral lymph node, <3cm in greatest dimension

Question 20

N2 stage head and neck (except nasopharynx, oropharynx, hypopharynx, and thyroid)

Answer 20

N2a: Single ipsilateral lymph node >3 but <6cm in greatest dimension
N2b: in multiple ipsilateral lymph nodes none >6cm in greatest dimension
N2c: metastasis in bilateral or contralateral lymph nodes >6cm in the greatest dimension.

Question 21

N3 stage head and neck (except nasopharynx, oropharynx, hypopharynx, and thyroid)

Answer 21

Metastasis in a lymph node >6cm in greatest dimension

Question 22

Lymphatic draining of the larynx

Answer 22

Glottis: extremely rare nodal involvement
Subglottis: into the peritracheal and low cervical nodes
Supraglottis: into the peritracheal, cervical, submental, and submaxillary

Question 23

Expected direct spread of larynx tumour

Answer 23

True cords
False cords
Arytenoid muscles
Epiglottis
Hypopharynx
Aryepiglottic folds
Venticles

Question 24

Treatment method for in-situ larynx cancer

Answer 24

Endoscopic stripping
Laser excision
RT
Or stringent follow-up

Question 25

Treatment method for T1-2 stage larynx cancer

Answer 25

RT is preferred, voice quality is better with RT, easily accomplished with minimal side effects
Surgery is reserved for salvage

Question 26

Treatment method for T3-4 stage larynx cancer

Answer 26

Fixed cord lesions indicate deep muscle &/or cartilage infiltrations.
Some can be treated with RT with surgery to salvage
If bilateral then surgery is required

Question 27

Negative prognosis factors for head and neck cancers

Answer 27

Tumours that cross the midline
Invasion of the lamina propria or submucosa
Poorly differentiated
Non-SCC
Fixed lymph nodes
Cranial nerve involvement
Vascular invasion

Question 28

Larynx anatomy

Answer 28

Is contiguous with the lower portion of the pharynx above.

It extends from the tip of the epiglottis at the level of the C3 vertebrae to the lower border of the cricoid cartilage.

Question 29

Common TDF’s for treatment of larynx cancer

Answer 29

The hypofractionated dose of 6600cGy/220cGy/# to the gross tumour with 5400cGy to elective lymph nodes.
A conventional fractionation dose of 7000cGy at 200cGy/# to the gross tumour volume and a lower dose to elective lymph nodes.

Question 30

Radiation therapy of larynx cancer

Answer 30

Typically treated with two opposing lateral fields.
The typical field size of 5x5cm for T1/T2 lesions up to 6x6cm.
Daily fraction doses of 200cGy or more results in superior outcomes to smaller daily doses.
The treatment of small fields for early glottic cancers rarely in severe complications.
Large T3/T4 lesions are treated with RT alone, salvage surgery can be done at the time of recurrence.
RT is the best method for voice preservation.
Equivalent control rates have been seen for both surgery and RT, usually decided at the discretion of the RO.

Supraglottic tumours tend to be large and bulky with spread superiorly to the epiglottis, and lymph node spread in 40-50% of cases therefore the treatment area is much larger than glottic tumours.

• surgery can control 80% of supraglottic tumours while RT offers 75% local control.
• RT for T3/T4 supraglottic nodes in contraindicated.

Subglottic lesions are treated with total laryngectomy with postoperative radiation therapy.

Question 31

Survival rates of larynx cancer

Answer 31

Glottic cancer: 
- 80-90% without cord fixation 
- 50-60% with cord fixation
Supraglottic cancer:
- 60-75% 5-year survival without involved lymph nodes
- 30-50% with involved nodes