(See also Overview of Head and Neck Tumors.)
Squamous cell carcinoma is the most common cancer of the larynx. In the US, it is 4 times more common among men and is more common among people of lower socioeconomic status. Over 95% of patients are smokers; 15 pack-years of smoking increase the risk 30-fold. The incidence of laryngeal cancer is about 13,000 new cases per year and is decreasing, particularly among men, most likely due to changes in smoking habits. Annual deaths are about 3700.
Sixty percent of patients present with localized disease alone; 25% present with local disease and regional nodal metastatic disease; and 15% present with advanced disease, distant metastases, or both. Lymph node metastasis are more common in supraglottic and subglottic tumors than with glottic cancers due to the minimal lymphatic drainage of the glottis. Distant metastases occur most frequently in the lungs and liver.
Common sites of origin are the true vocal cords (glottis) and the supraglottic larynx. The least common site is the subglottic larynx, where only 1% of primary laryngeal cancers originate. Verrucous carcinoma, a rare variant of squamous cell carcinoma, usually arises in the glottic area and has a better survival rate than standard squamous cell carcinoma.
Symptoms and signs differ based on the involved portion of the larynx. Hoarseness is common early in glottic cancers but is a late symptom for supraglottic and subglottic cancers. Patients with subglottic cancer often present with airway obstruction, and hoarseness is a common late symptom. Patients with supraglottic cancer often present with dysphagia; other common symptoms include airway obstruction, otalgia, development of a neck mass, or a "hot potato" voice. Patients with these symptoms should be referred for direct laryngoscopy without delay.
All patients who have hoarseness for > 2 to 3 weeks should have their larynx examined by a head and neck specialist. Some practitioners use a mirror to evaluate the larynx, but most prefer a flexible fiberoptic examination. Any lesions discovered require further evaluation, usually with operative endoscopy and biopsy, with concomitant evaluation of the upper airway and GI tract for coexisting cancers. The incidence of a synchronous second primary tumor may be as high as 10%.
Patients with confirmed carcinoma typically have neck CT with contrast and a chest x-ray or chest CT. Most clinicians also do PET of the neck and chest at the time of diagnosis.
For purposes of clinical stage classification, the larynx is divided into 3 regions: supraglottis, glottis, and subglottis (1). Laryngeal cancer is staged according to size and site of the primary tumor (T). number and size of metastases to the cervical lymph nodes (N), and evidence of distant metastases (M). There are separate N categories for HPV-related and HPV-unrelated cancers. Staging usually requires imaging with CT, MRI, or both, and often PET.
Clinical staging (cTNM) is based on the results of the physical examination and tests done before surgery. Pathologic staging (pTNM) is based on the pathologic characteristics of the primary tumor and the number of positive nodes found during surgery.
Extranodal extension is incorporated into the "N" category for metastatic cancer to neck nodes. Clinical diagnosis of extranodal extension is based on finding evidence of gross extranodal extension during the physical examination together with imaging tests confirming the finding. Pathologic extranodal extension is defined as histologic evidence of tumor in a lymph node extending through the lymph node capsule into the surrounding connective tissue, with or without associated stromal reaction.
Early-stage glottic carcinoma has a 5-year survival rate of 85 to 95%. The overall 5-year survival rate for patients with laryngeal cancer is 60%. Patients who present with regional nodal disease have a 43% 5-year survival rate, and those who present with distant metastases have a 30% 5-year survival rate.
Early-stage glottic carcinoma is treated with laser excision, radiation therapy, or occasionally open laryngeal surgery. Endoscopic laser resection and radiation therapy usually preserve a normal voice and post-treatment function and have similar cure rates. Whether surgery or radiation is used to treat early-stage glottic cancer usually depends on the location of the lesion in the glottis, the preferences of the treating institution, and the patient.
For advanced glottic carcinoma, defined by a lack of vocal cord mobility or extension into the tongue, most patients are treated with both chemotherapy and radiation therapy. If the patient presents with extension outside of the larynx or with cartilage invasion, a laryngectomy provides the best oncologic results; the laryngectomy is commonly total, but endoscopic laser resection or open partial laryngectomy can be used in select appropriate cases. A total laryngectomy is also commonly used for salvage situations; however, endoscopic resection or open partial laryngectomy may sometimes be used in these situations.
Early supraglottic carcinoma can be effectively treated with radiation therapy or partial laryngectomy. Laser resection has shown considerable success on early-stage supraglottic squamous cell carcinomas and minimizes functional changes after surgery. If the carcinoma is more advanced but does not affect the true vocal cords, a supraglottic partial laryngectomy can be done to preserve the voice and glottic sphincter. If the true vocal cords also are affected, a supracricoid laryngectomy or a total laryngectomy is required if surgery is chosen.
As with glottic carcinoma, most advanced-stage supraglottic cancers initially are treated with chemotherapy and radiation therapy. The supraglottis has a rich lymphatic network, so the neck must be addressed in all patients with supraglottic cancer.
Early subglottic carcinoma is rarely treatable with endoscopic resection so radiation is the mainstay of treatment. For more advanced subglottic lesions or lesions with metastasis, chemoradiation is the standard of care unless there is extension outside of the larynx or extensive cartilage invasion in which case total laryngectomy provides the best outcome.
(See also the National Cancer Institute’s summary Laryngeal Cancer Treatment.)
Rehabilitation may be required after either surgical or nonsurgical treatment. Significant swallowing problems are common after chemotherapy and radiation therapy and may require esophageal dilation, swallowing therapy, or, in severe cases, surgical replacement of the pharynx or gastrostomy tube feedings. Swallowing also is affected by surgery and may require swallowing therapy or dilation as well.
Speech, on the other hand, is more significantly affected by surgery. After total laryngectomy, the patient requires creation of a new voice by way of
In all 3 techniques, sound is articulated into speech by the pharynx, palate, tongue, teeth, and lips.
Esophageal speech involves taking air into the esophagus during inspiration and gradually eructating the air through the pharyngoesophageal junction to produce a sound.
A tracheoesophageal puncture involves placement of a one-way valve between the trachea and esophagus to facilitate phonation. This valve forces air into the esophagus during expiration to produce a sound. Patients receive physical rehabilitation, speech therapy, and appropriate training in the maintenance and use of this valve and must be cautioned against the possible aspiration of food, fluids, and secretions.
An electrolarynx is a battery-powered sound source that is held against the neck to produce sound. Although it carries a great deal of social stigma for many patients, it has the advantage of being functional immediately with little or no training.
Hoarseness is common early in glottic cancers but is a late symptom for supraglottic and subglottic cancers.
All patients who have hoarseness for > 2 to 3 weeks should have their larynx examined by a head and neck specialist.
Patients with confirmed carcinoma typically have neck CT with contrast and often PET/CT for advanced stages.
Treat early-stage (T1 and T2) cancer with surgery or radiation therapy.
Treat moderately advanced (T3) cancer with radiation therapy and sometimes chemotherapy.
Treat advanced cancer (T4) that extends outside of the larynx with surgery and then postoperative chemotherapy and radiation therapy.