Laryngeal Cancer and Tumor Staging

The larynx, commonly called the voice box, is subdivided into three parts: the glottis, the subglottis, and the supraglottis. The glottic larynx is that portion which contains the vocal cords. The supraglottic larynx is that portion which lies above the glottis; the subglottis is the portion of the larynx beneath the vocal cords and leading up to the trachea (wind pipe).

Cancers of the larynx account for the majority of head and neck cancers; however, head and neck cancers account for only about 9% of all cancers diagnosed annually.

In the United States, there are more cancers affecting the glottic larynx than the supraglottic larynx. Conversely, in Europe and many other parts of the world, supraglottic cancers greatly outnumber glottic cancers. Cancers of the glottic larynx are more likely to be detected early because even small lesions produce voice changes readily noticeable by the patient and his/her family members; however, patients with smoking-related chronic laryngitis who are used to a chronically hoarse voice may not detect voice changes produced by an early cancer at this location. The supraglottis tends to be a more silent location because tumors here do not affect the voice until they are significantly more advanced. Patients with tumors in this area may present with a sore throat, pain on swallowing (odynophagia), or ear pain (otalgia).

Laryngeal cancers are staged according to the TNM system as explained in the latest manual of the American Joint Commission on Cancer. There is a separate staging system for cancers that affect different subdivisions of the larynx. Subglottic cancer is quite rare and so we will focus on cancers affecting the glottic and supraglottic larynx.

According to the staging system, a tumor is graded on factors related to the location of the primary tumor and assigned a value ranging from T1 to T4. Depending on whether or not there is evidence of cancer spread to the lymph nodes of the neck (regional metastases), the cancer is staged N0-N2. Distant metastatic spread of the cancer to other organs can occur, most commonly to the lungs, liver, and bone. If there are distant metastases present the patient is staged M1, if not, the stage is M0.

Laryngeal Cancer T staging

Glottic Cancers

* T1a: Tumor is confined to one vocal cord with normal mobility
* T1b: Tumor involves both vocal cords but mobility is normal
* T2: Extension of the tumor from the vocal cords to the supraglottic or subglottic larynx or impaired vocal cord mobility
* T3: Tumor is confined to the larynx but there is fixation of the vocal cord
* T4: There is invasion through thyroid cartilage and/ or other tissues beyond larynx (e.g., trachea, thyroid, pharynx, soft tissue of neck).

Supraglottic Cancers