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Risk factors for laryngeal CA
Tobacco, alcohol, plummer vinson, h/o juvenile papillomatosis, environental factors (metal, plastics, paint, wood dust, asbestos)
What's the quadrangular membrane?
fibroelastic membrane, supports supraglottis, extends from epiglottis to arytenoid and corniculate cartilage.
What's the conus elasticus?
Fibroelastic membrane, supports vocal fold, extends from cricoid cartilage to merge with vocal ligament. Resists spread of glottic and subglottic cancers.
What defines the pre-epiglottic space? What are the pathways of tumor spread into the pre-epiglottic space?
- Bound by hyoid bone, thyrohyoid membrane, hyoepiglottic ligament, thyroepiglottic ligament, and epiglottis.
- may enter from anterior commissure or with supraglottic extension; contiguous with paraglottic space
Define Reinke's Space
Superficial lamina propria of TVC. Lack of lymphatics and blood vessels allow tumor spead.
What is the source of the controversy regarding spread of tumor via Broyles tendon?
- Allows spread: no perichondrium at insertion site of thyroid cartilage
- Inhibits spread: histopathologic studies demonstrate barrier.
The most common site of supraglottic SCC
Embryologic derivation of larynx
- Supraglottis: 3rd and 4th branchial arches. Embryotic fusion plate between supraglottis and glottis, different lymphatics, barrier to tumor spread
- Glottis/subglottis: 6th branchial arch
What neck levels are at risk for regional mets in supraglottic CA?
II, III, IV bilaterally. Even low grade have >20% risk of mets, so must treat both necks even without clinically apparent nodes (some authors say T2 and greater).
Name of a tumor found at the aryepiglottic fold, usually a basaloid squamous cell carcinoma.
Marginal tumor. Aggressive, similar to a hypopharyngeal pyriform sinus tumor.
What type of epithelium is found in the larynx?
- Supraglottis: pseudostratified, ciliated, columnar epithelium
- Glottis: stratified squamous epithelium
- Subglottis: pseudostratified, ciliated, columnar epithelium
Lymphatic drainage of the glottis
Ipsilateral II, III, IV. Elective neck dissection NOT indicated for early glottic cancer, rate of occult mets less than 20%. Address these levels for N0 T3/T4 Ca. MRND for palpable nodes.
VF fixation suggests involvement of which structures?
- thyroarytenoid, lateral or posterior cricoarytenoid, interarytenoid muscles
- cricoarytenoid joint
- perineural invasion
For what type of malignant lesions is microflap excision indicated?
T1, superficial, midmebranous lesions. Dissects superficial lamina propria, spares the vocal ligament.
Management of carcinoma in situ or microinvasive laryngeal carcinoma
- smoking/alcohol cessation
- radiation vs surgical excision
- f/u ever 2-3 months for 5 years, low threshold for biopsy
- repeat biopsy every 3 months until 2 consecutive negative results
What did intergroup R91-11 demonstrate regarding the timing of chemo and RT in advanced glottic ca?
RT with concurrent chemo had better organ preservation than induction chemo followed by RT or RT alone.
Do you address the neck in an N0 subglottic ca?
No. Ipsilateral MRND for clinical nodal disease.
6 contraindications for partial laryngectomy
- fixed vocal cords (except supracricoid laryngectomy)
- cartilage invasion
- subglottic extension
- significant oropharyngeal extension
- interarytenoid involvement
- tumor spread into the neck
When is a cordectomy (transoral or via laryngofissure) indicated?
T1 glottic limited to the middle third of the cord. No extension to the vocal process or anterior commissure. No involvement of subglottis, ventricle, or false cord.
Contraindications to a supraglottic laryngectomy (horizontal hemilaryngectomy)
- advanced disease, some T3 tumors amenable
- involvement of VF, ventricle, thyroid cartilage, arytenoid, interarytenoid region, piriform, or base of tongue
- FEV1/FVC must be >50%
What is removed in a supraglottic partial laryngectomy?
- Epiglottis, AE folds
- False vocal cords
- Preepiglottic space, portions of hyoid, thyroid cartilage
- spares TVC and arytenoids (endoscopic procedure preserves SLN and hyoid)
An extended supraglottic partial laryngectomy includes what structures in addition to those in the standard procedure?
base of tongue, hypopharynx, or one arytenoid
Contraindication for a vertical partial laryngectomy?
- only for select T1, T2 lesions
- extends beyond 1/3 of opposite cord
- <10 mm anterior subglottic extension, <5 mm posterior subglottic extension
- posterior commisure, cricoarytenoid, AE fold, posterior surface of arytenoid involvement
- paraglottic space
- must have FEV1/FVC >50%
What is removed in a vertical partial laryngectomy?
- involved cord from anterior commisure to vocal process
- up to half of the contralateral cord
- ipsilateral false cord, ventricle, paraglottic space, and thyroid cartilage (3mm strip of posterior cartilage is preserved)
What structures are removed in a supracricoid laryngectomy?
- Entire thyroid cartilage
- bilateral true and false vocal cords
- one arytenoid (can spare both if neither are involved)
- paraglottic space
- preserved: cricoid, hyoid, at least one arytenoid for speech and swallowing. Epiglottis can be spared. May perform cricohyoidopexy or cricohyoidoepiglottopexy)
Indications for a supracricoid laryngectomy?
- Select T3/T4 glottic cancers that involve the paraglottic space, preepiglottic space, ventricle, limited thyrodi cartilage or epiglottis.
- must have FEV1/FVC >50%
Contraindications for a supracricoid laryngectomy?
- arytenoid fixationinfraglottic extension to cricoid
- major pre-epiglottic involvement
- invasion of thyroid cartilage perichondrium, posterior arytenoid mucosa, hyoid bone
- extralaryngeal involvement
- FEV1/FVC must be greater than 50%
What is a near-total or 3/4 laryngectomy?
- creates communication between pharynx and trachea
- preserves one arytenoid to prevent aspiration through this shunt
- Suprahyoid epiglottis
- Infrahyoid epiglottis
- Laryngeal surface of AE folds
- Posterior surface of AE folds
- False cords
How do you treat the neck in a T3 glottic ca?
T3 has rare nodal mets, unless there is transglottic spread. There's no need to address an N0 neck.
What are the rates of malignant transformation in mild dysplasia of the larynx? Severe dysplasia?
- mild dysplasia: as high as 11%
- severe dysplasia and CIS: up to 45%, but 30% is generally accepted
Benefits of surgery in CIS? Benefits of RT?
Surgery gives you a histologic diagnosis and can be repeated as often as necessary. However, the recurrence rate after surgery is about 20%. With repeated procedures, the control rate for surgery is equivalent to RT.
Two most widely used lasers for in-office treatment of dysplasia, leukoplakia, and keratosis.
585nm PDL and 532nm pulsed KTP lasers
Define the paraglottic space and it's role in laryngeal cancer spread.
The paraglottic space lies lateral to the true and false cords and extends laterally to the thyroid cartilage. Anteriorly, the PGS is contiguous with the pre-epiglottic space, and tumors can spread along this pathway. Paraglottic space involvement in either a glottic or supraglottic tumor is staged as at least a T3. Tumors in this space may spread to involve all three divisions of the larynx.
What are the indications for primary total laryngectomy?
- advanced T3/4 tumors, poor candidates for laryngeal preservation
- posterior commissure or b/l arytenoid involvment
- circumferential submucosal disease
- invasion of cricoid cartilage
- hypopharyngeal tumor with involvement of the postcricoid mucosa
- large metastatic or thyroid tumors invading larynx bilaterally
- Poor pulmonary function or high risk of aspiration
- tumors resistant to chemo-rt and unable to be cured by endoscopic resection (e.g. adenocarcinoma, spindle cell, soft tissue sarcoma, minor salivary gland, large cell neuroendocrine, and chondrosarcoma)
How should the thyroid be addressed in a TL?
Controversial. Higher risk of direct gland involvement in patients who have invasion of the thyroid or cricoid cartilage. The highest risk is in transglottic cancers that extend more than 1 cm subglotticaly. High risk pts should have a thyroidectomy.
What are the predisposing risk factors for the development of a post-laryngectomy pharyngo-cutatneous fistula? How would you manage this complication?
Most common complication after laryngectomy (8-25%). Predisposing factors include, pharyngolaryngectomy, chronic CHF, postoperative Hgb level less than 12.5, patients who previously underwent trach, preoperative RT, diabetes, malnutrition. Majority close spontaneously (70%).
What did the Veterans Affairs Laryngeal Cancer Study Group find?
Induction chemotherapy plus radiation compared with surgery plus radiation in patients with advanced laryngeal cancer. Chemotherapy and RT preserved the larynx in 64% of patients, without compromising overall survival (failures went on to TL).