General Information About Laryngeal Cancer
Incidence and Mortality
Estimated new cases and deaths from laryngeal cancer in the United States in 2014:
- New cases: 12,630.
- Deaths: 3,610.
The larynx is divided into the following three anatomical regions:
- The supraglottic larynx includes the epiglottis, false vocal cords, ventricles, aryepiglottic folds, and arytenoids.
- The glottis includes the true vocal cords and the anterior and posterior commissures.
- The subglottic region begins about 1 cm below the true vocal cords and extends to the lower border of the cricoid cartilage or the first tracheal ring.
The supraglottic area is rich in lymphatic drainage. After penetrating the pre-epiglottic space and thyrohyoid membrane, lymphatic drainage is initially to the jugulodigastric and midjugular nodes. About 25% to 50% of patients present with involved lymph nodes. The precise figure depends on the T stage. The true vocal cords are devoid of lymphatics. As a result, vocal cord cancer confined to the true cords rarely, if ever, presents with involved lymph nodes. Extension above or below the cords may, however, lead to lymph node involvement. Primary subglottic cancers, which are quite rare, drain through the cricothyroid and cricotracheal membranes to the pretracheal, paratracheal, and inferior jugular nodes, and occasionally to mediastinal nodes.Risk Factors
A clear association has been made between smoking, excess alcohol ingestion, and the development of squamous cell cancers of the upper aerodigestive tract. For smokers, the risk of the development of laryngeal cancer decreases after the cessation of smoking but remains elevated even years later when compared to that of nonsmokers. If a patient who has had a single cancer continues to smoke and drink alcoholic beverages, the likelihood of a cure for the initial cancer, by any modality, is diminished, and the risk of second tumor is enhanced. Because of clinical problems related to smoking and alcohol use in this population, many patients succumb to intercurrent illness rather than to the primary cancer. (Refer to the PDQ summary on Smoking in Cancer Care for more information.)Clinical Features
Supraglottic cancers typically present with sore throat, painful swallowing, referred ear pain, change in voice quality, or enlarged neck nodes. Early vocal cord cancers are usually detected because of hoarseness. By the time they are detected, cancers arising in the subglottic area commonly involve the vocal cords; thus, symptoms usually relate to contiguous spread.Prognostic Factors
The most important adverse prognostic factors for laryngeal cancers include increasing T stage and N stage. Other prognostic factors may include sex, age, performance status, and a variety of pathologic features of the tumor, including grade and depth of invasion.
Prognosis for small laryngeal cancers that have not spread to lymph nodes is very good with cure rates of 75% to 95% depending on the site, tumor bulk, and degree of infiltration. Although most early lesions can be cured by either radiation therapy or surgery, radiation therapy may be reasonable to preserve the voice, leaving surgery for salvage. Patients with a preradiation hemoglobin level higher than 13 g/dL have higher local control and survival rates than patients who are anemic.
Locally advanced lesions are treated with combined modality treatment involving radiation and chemotherapy with or without surgery, the aim of which is laryngeal preservation in appropriately selected candidates. Distant metastases are also common, even if the primary tumor is controlled.
Intermediate lesions have intermediate prognoses, depending on site, T stage, N stage, and performance status. Therapy recommendations for patients with these lesions are based on a variety of complex anatomic, clinical, and social factors, which should be individualized and discussed in multidisciplinary consultation (surgery, radiation therapy, and dental and oral surgery) prior to prescribing therapy.Follow-up and Survivorship
Second primary tumors, often in the aerodigestive tract, have been reported in as many as 25% of patients whose initial lesion is controlled. A study has shown that daily treatment of these patients with moderate doses of isotretinoin (i.e., 13-cis-retinoic acid) for 1 year can significantly reduce the incidence of second tumors. No survival advantage has been demonstrated, partially because of recurrence and death from the primary malignancy.
Patients treated for laryngeal cancers are at the highest risk of recurrence in the first 2 to 3 years. Recurrences after 5 years are rare and usually represent new primary malignancies. Close, regular follow-up is crucial to maximize the chance for salvage. Careful clinical examination and repetition of any abnormal staging study are included in follow-up, along with attention to any treatment-related toxic effect or complication.References
- American Cancer Society.: Cancer Facts and Figures 2014. Atlanta, Ga: American Cancer Society, 2014. Available online. Last accessed March 26, 2014.
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