Overview
The larynx is the second most common site of head and neck cancer. It accounts for 1-5% of all malignancies. The mean age of laryngeal cancer presentation is 40-70 years. It has a 5-year survival rate of 65%.
- Risk factors
- Smoking and alcohol use
- Highest risk in current smokers
- Risk increases with the number of cigarettes
- Risk reduces to level of individual who have never smoked approximately 20 years after cessation
- History of Recurrent Respiratory Papillomatosis (HPV)
- Previous head and neck Radiation
- Plummer-Vinson Syndrome
- Premalignant lesions: Leukoplakia, Hyperkeratosis with atypia, Carcinoma in Situ
- Genetic mutations: p53, p16, cyclin D1
- Occupational toxins: Asbestos, wood dust, coal dust, cement dust, polycyclic aromatic hydrocarbons
- Fanconi’s anemia
- Congenital dyskeratosis
- Low socioeconomic status
- Smoking and alcohol use
- Signs and symptoms
- Hoarseness
- Persistent
- Hoarseness
- Differential diagnosis
- Fungal laryngitis
- Sarcoidosis
- Tuberculosis
- Wegener’s granulomatosis
- Benign vocal cord tumors: Polyp, Cyst, Hemangioma, Papilloma
Sites of Laryngeal Carcinoma
Anatomic Boundaries
| Site | Anatomical boundaries | Histology |
|---|---|---|
| Supraglottic Site | From the epiglottis to the junction of the ventricle and true vocal cord | Respiratory epithelium |
| Glottic Site | From the superior surface of the true vocal fold to 1 cm below the true vocal folds | Stratified squamous epithelium |
| Subglottic Site | From 1cm below the true vocal folds to the inferior cricoid cartilage | Respiratory epithelium |
Supraglottic Laryngeal Cancer
Accounts for 40% of laryngeal cancer. It has a poor prognosis due to early spread and late detection. The embryological fusion plate forming between the supraglottis and glottis functions as a barrier for the tumor and creates separate vascular supplies. Supraglottic tumors invade superiorly towards the base of the tongue. They have a 25-75% risk of regional metastasis, primarily to nodal levels II, III, IV with bilateral nodal metastasis.
Marginal Tumor: a tumor found at the aryepiglottic fold, usually basaloid SCC, aggressive, and similar to a hypopharyngeal piriform sinus tumor
- Signs and symptoms
- Sore throat
- Hemoptysis
- Aspiration
- Dysphagia
- Odynophagia
- Stridor (airway obstruction)
- Referred otalgia
- Weight loss
- Globus sensation
AJCC Staging Primary Tumor
| Primary tumor | Description |
|---|---|
| T1 | Tumor limited to 1 subsite of the supraglottis with normal vocal cord mobility |
| T2 | Tumor invades the mucosa of more than 1 adjacent subsite of the supragllotis or glottis or region outside the supraglottis without vocal cord fixation |
| T3 | Vocal cord fixation or tumor invades the post-cricoid area, pre-epiglottic space, praglottic space, or inner cortex of thyroid cartilage |
| T4a | Invasion through the thyroid cartilage or tissues beyond the larynx |
| T4 | Invades prevertebral space, encases the carotid artery, or invades mediastinal structures |
Glottic Carcinoma
Glottic carcinoma is the most common site of laryngeal cancer, accounting for 60%. It is diagnosed at early stages due to Hoarseness and barriers that limit its spread (vocal ligament, thyroglottic ligament, and conus elasticus). The glottis has poor lymphatic supply, hence limited regional spread. Primarily drains to nodal level II, III, IV. Lymphatic spread is ipsilateral and occurs only after it has spread beyond the vocal cords.
- Signs and symptoms
- Hoarseness of voice (early)
- Stridor (large growth)
- Aspiration
- Dysphagia
- Odynophagia
- Airway obstruction
- Weight loss
- Sore throat
AJCC Staging primary tumor
| Primary tumor | Description |
|---|---|
| T1 | Tumor limited to vocal folds with normal mobility |
| T2 | Tumor extends to the subglottis or supraglottis, or impaired vocal fold mobility |
| T3 | Vocal fold fixation, or invasion of paraglottic space, or invasion of the inner cortex of the thyroid cartilage |
| T4 | Further invasion |
Subglottic Carcinoma
Subglottic carcinoma is rare. It is often silent, poorly differentiated and extends towards the cricoid cartilage. It has poor prognosis. Spreads to paratracheal nodes (Level VI). It may invade the cricothyroid membrane, thyroid glands, and muscles of the neck.
- Signs and symptoms
- Stridor (early and biphasic)
- Hoarseness (Late)
- Dysphagia
- Odynophagia
- Hemoptysis
- Weight loss
- Sore throat
AJCC Staging primary tumor
| Primary tumor | Description |
|---|---|
| T1 | Tumor limited to the subglottis |
| T2 | Tumor involves the vocal folds with normal or impaired mobility |
| T3 | Tumor limited to the larynx with vocal fold fixation, or invasion of the paraglottic space, or invasion of the inner cortex of the thyroid cartilage |
| T4 | Further invasion |
Histological Subtypes
| Histology | Description |
|---|---|
| Squamous Cell Carcinoma | >95% of Laryngeal Cancer. Basaloid SCC is the most aggressive high-grade variant. |
| Verrucous Carcinoma (Ackerman’s Tumor) | Slow-growing and locally destructive. Appears exophytic (warty), fungating, and grey-white in color. It rarely metastasizes and has excellent prognosis. |
| Adenocarcinoma | 1% of laryngeal cancer. Primarily in the supraglottic and subglottic regions. More aggressive than SCC. |
| Adenoid Cystic Carcinoma | Perineural spread, indolent course and may present with distant metastasis years after primary treatment |
| Spindle Cell Carcinoma | Poorly differentiated variant of SCC with spindle cell stroma component |
| Neuroendocrine Tumors | Paragangliomas, Carcinoid tumors, Small cell carcinoma |
| Sarcomas | Fibrosarcoma, chondrosarcoma, malignant fibrous histiocytoma, rhabdosarcoma |
| Metastatic | Rare. Primaries from the kidney, prostate, breast, stomach, and lung. |
Premalignant Glottic Lesions
| Histology | Description |
|---|---|
| Hyperplasia and Hyperkeratosis | An increase in the number of cells and keratin production |
| Mild Dysplasia | Mild atypia |
| Moderate Dysplasia | Moderate atypia |
| Severe Dysplasia (Carcinoma in Situ) | Full thickness features of malignancy without invasion of the basement membrane |
| Microinvasive Carcinoma | Discrete foci invade beyond the basement membrane |
| Invasive Carcinoma | Invasion through the basement membrane |
Management
- Investigations
- Indirect laryngoscopy
- Flexible nasolaryngoscopy: to visualize cord mobility
- Rigid endoscopy of the larynx
- Direct laryngoscopy under general anaesthesia + Biopsy
- Incisional biopsy: less morbidity. May risk missing the tumor
- Excisional biopsy: therapeutic for early glottic carcinoma
- Microflap excision: spares the vocal ligaments
- Vocal fold stripping: removes the vocal fold cover
- Chest X-ray: for chest metastasis, mediastinal nodes, and co-existing lung disease
- CT scan base of skull to thoracic inlet
- Other investigations
- PET scan: follow-up and detection of distant met
- Echo/ECG
- Pulmonary function tests
- Liver function tests
- Urea and Creatinine
- Electrolytes
- Full Hemogram
- Treatment of Carcinoma in Situ and Micro-Invasive Carcinoma
- Smoking and Alcohol Cessation
- Radiation therapy versus Surgical excision
- Radiation for recurrence after initial excision
- Follow-up q2-3 months for 5 years
- Excisional biopsy q3months until 2 consecutive negative results for microinvasive carcinoma
- CO2 laser (does not provide biopsy specimen)
- Treatment of Laryngeal Carcinoma
- Primary radiation to primary site
- CO2 laser
- Conservative Laryngeal Surgery
- Total Laryngectomy + Neck dissection
- Organ Preservation: Induction chemotherapy then Chemoradiation, Chemoradiation
- Palliation: Tracheostomy, Gastrotomy
- Post-op complications
- Fistula: increased incidence with radiation therapy
- Tracheotomy Complications: Pneumothorax, Hemorrhage, Subcutaneous emphysema
- Speech alterations
- Persistent aspiration, bronchopneumonia, and Swallowing problems
- Esophageal or pharyngeal stenosis
- Perichondritis and Chondritis
- Stomal Stenosis
- Post-operative Voice Management
- Writing
- Artificial larynx (Electrolarynx)
- Esophageal speech
- Tracheoesophageal Puncture
