Larynx Flashcards
The peak incidence of larynx cancer
50-60 years old, more common in men than women
Location of larynx cancer
65% occur in the true glottis
30% in the supraglottis
5% in the subglottis
Risk factors of larynx cancer
Usually associated with smoking (10 fold risk) and alcohol consumption
It maybe due to occupational exposure
Or use of voice extensively
Most common pathology of larynx cancer
SCC is the most dominant
Signs and symptoms of larynx cancer
True glottic tumours affect speech (hoarseness)
Advanced tumours may cause difficulty breathing and pain
The spread of larynx cancer
Lymph node spread only if an extensive disease that is creeping superiorly into the supraglottic region
T1 stage larynx cancer (glottis)
Tumour limited to vocal cords with normal mobility
T1a: tumour limited to one vocal cord
T1a: tumour involves both vocal cords
T2 stage larynx cancer (glottis)
Tumour extends to supraglottis or subglottis with impaired vocal cord mobility
T3 stage larynx cancer (glottis)
Tumour limited to the larynx with vocal cord fixation OR invasion of paraglottic space OR inner cortex of thyroid cartilage
T4 stage larynx (glottis)
T4a: moderately advanced local disease
T4b: very advanced local disease
T1 stage larynx (supraglottis)
T1: the tumour is limited to one subsite of the supraglottis with normal vocal cord mobility
T2 stage larynx (supraglottis)
Tumour invades mucosa or more than one adjacent structure without fixation of the larynx.
T3 stage laynx (supraglottis)
Limited to larynx with vocal cord fixation or invades post cricoid cartilage, pre-epiglottic space or para-glottic space
T4 stage larynx (supraglottis)
T4a: moderately advanced local disease
T4b: very advanced local disease
T1 stage larynx (subglottis)
Limited to subglottis
T2 stage larynx (subglottis)
Extends to vocal cords with normal or impaired mobility
T3 stage larynx (subglottis)
limited to larynx with vocal cord fixation
T4 stage larynx (subglottis)
T4a: moderately advanced local disease
T4b: very advanced local disease
N1 stage head and neck (except nasopharynx, oropharynx, hypopharynx, and thyroid)
Single ipsilateral lymph node, <3cm in greatest dimension
N2 stage head and neck (except nasopharynx, oropharynx, hypopharynx, and thyroid)
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.
N3 stage head and neck (except nasopharynx, oropharynx, hypopharynx, and thyroid)
Metastasis in a lymph node >6cm in greatest dimension
Lymphatic draining of the larynx
Glottis: extremely rare nodal involvement
Subglottis: into the peritracheal and low cervical nodes
Supraglottis: into the peritracheal, cervical, submental, and submaxillary
Expected direct spread of larynx tumour
True cords False cords Arytenoid muscles Epiglottis Hypopharynx Aryepiglottic folds Venticles
Treatment method for in-situ larynx cancer
Endoscopic stripping
Laser excision
RT
Or stringent follow-up
Treatment method for T1-2 stage larynx cancer
RT is preferred, voice quality is better with RT, easily accomplished with minimal side effects
Surgery is reserved for salvage
Treatment method for T3-4 stage larynx cancer
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
Negative prognosis factors for head and neck cancers
Tumours that cross the midline Invasion of the lamina propria or submucosa Poorly differentiated Non-SCC Fixed lymph nodes Cranial nerve involvement Vascular invasion
Larynx anatomy
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.
Common TDF’s for treatment of larynx cancer
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.
Radiation therapy of larynx cancer
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.
Survival rates of larynx cancer
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
