Laryngeal Cancer

Excerpt

Laryngeal cancers represent one-third of all head and neck cancers and are a significant source of morbidity and mortality. These cancers primarily originate from any of the 3 subdivisions of the larynx—the supraglottis, glottis, and subglottis—and each maintains its own staging system. Squamous cell carcinoma is the most common histologic subtype, with nearly all squamous cell carcinoma variants described in this anatomic location (see Image. Anatomy of the Larynx). Other very rare histologies include sarcomas of the laryngeal skeleton, minor salivary gland carcinomas, melanoma, and lymphomas. Laryngeal cancers are most often diagnosed in patients with a significant smoking history, who are also at risk for cancers in the remainder of the aerodigestive tract. Confounding associations with ethanol consumption (supraglottis) and various environmental exposures, such as Agent Orange, asbestos, or metal-working occupational fumes (all subsites), also exist. Primary subglottic cancer is quite rare and portends a bleak prognosis. Unlike areas of the oropharynx, such as Waldeyer's ring, the association with human papillomavirus (HPV) is not nearly as robust. While HPV-related oncogenetic pathways, such as p16, have been described in laryngeal carcinomas, the etiologic and prognostic significance of these viral-related pathways remains to be elucidated.

Each primary subsite of laryngeal carcinoma carries different implications in symptomatic presentation, patterns of spread, prognosis, and treatment paradigms. Early-stage disease is often highly treatable or curable in the supraglottis and glottis, although the prognosis remains poor in the subglottis. Early-stage (stage I or II) laryngeal cancer can be successfully treated with monotherapy, meaning a single-modality of treatment, either surgical or radiation therapy, which typically preserves the larynx. In contrast, advanced-stage disease (stage III or IV) carries a significantly poorer prognosis across all subsites, although the pattern is maintained. Glottic primaries often yield the best outcomes, followed by supraglottic and then subglottic tumors. The treatment for advanced-stage laryngeal cancer warrants multimodal therapy, which may include surgery followed by radiation therapy, primary chemoradiation therapy, or a combination of all 3 methodologies (see Image. Laryngeal Cancer).

All the aforementioned generalizations pertain specifically to laryngeal squamous cell carcinoma. Minor salivary gland carcinoma of the larynx, laryngeal melanoma, and other rare carcinomas are primarily managed within clinical trials due to their rarity, precluding standardized treatment recommendations. Sarcoma of the larynx, particularly chondrosarcoma (the most common subtype), is best treated surgically. Notably, it is a rare case where the overall prognosis is quite good, although the treatment often requires a total laryngectomy, which has severe consequences.