Key Glossary Terms Vocal Fold Atypia Non-cancerous but irregular cells in vocal fold epithelium; often leads to cancer; often recurs after removal Vocal Fold Early Cancer Cancer of vocal fold epithelium that is confined to the vocal folds and has not spread Vocal Fold Epithelium Surface lining of vocal folds composed of squamous cells Glossary

Cancer anywhere in the body has common characteristics. Cancer develops when cells designed to perform useful functions undergo changes that are ultimately harmful to the body. Such changes include:

• Uncontrolled growth
• A tendency to invade nearby tissues

In advanced cases cancer cells spread throughout the body causing death. As with all cancers, vocal fold cancer can be life threatening if left untreated.

There is a subtle transition from vocal fold atypia to early cancer. Determining the difference between the two conditions usually requires very careful microscopic examination of the tissues.

• Vocal fold atypia: Early cell changes that often lead to cancer.
  • Atypia (without cells not of normal type): One of the early changes that occurs in cells that will eventually become cancerous is that they begin to look different (atypical) from normal surrounding cells. These atypical cells are less organized in their pattern. In vocal fold atypia, the surface layer of vocal fold cells (epithelium) fails to show an orderly pattern of maturation (dysplasia).
  • Atypia is a "prequel" to cancer – pre-malignant. As with atypia anywhere in the body, vocal fold atypia (or dysplasia) can lead to vocal fold cancer, thus the need to identify and remove atypia promptly.
• Early vocal fold cancer: When abnormal-looking cells have invaded the deepest layer of the epithelium cover, the lesion is identified as an early cancer.

Key Information

Early vocal fold (or glottic) cancer refers to stage T1a or T1b and early T2 cancers.

• T1a: Early cancer that is confined to one vocal fold
• T1b: Early cancer that is confined to the vocal folds and involves both vocal folds
• T2a: Early cancer in one vocal fold that either:
  1. invades the supraglottis and/or subglottis, or
  2. causes impaired mobility of the vocal fold
• T2a: Early cancer in both vocal folds that either:
  1. invades the supraglottis and/or subglottis, or
  2. causes impaired mobility of the vocal fold

Criteria for Staging Vocal Fold Cancers

• the size of the cancer
• how it has affected the mobility of the involved vocal fold

Vocal fold cancer and atypia usually affect the surface cells (epithelium) of the vocal fold. The surface cells have typical features and are referred to as squamous cells. Vocal fold cancer is frequently squamous cell cancer, although other cell type cancers can occur.

Vocal fold cancers are thought to start out as pre-malignant vocal fold atypia. In fact, vocal fold atypia may be present for many years before transforming into cancer. The reason why this transition occurs is still unknown.

Red Flag

Early Detection Is Key

Uncertainty surrounding the transition of atypia into a cancerous lesion underscores the importance of seeking medical care for the condition as early as possible.

Atypia on left Vocal Fold	Normal Vocal Folds
A "close-up" view showing atypia lesions [indicated by arrows] on the left and right vocal fold (vf). The lesion on the right is smaller.	Normal vocal folds with no lesions on surface.
(click photographs for larger images)

• Non-smokers rarely develop vocal fold atypia or vocal fold cancer.
• Interestingly, physicians' knowledge about the risk of smoking is based on the observation that vocal fold atypia/cancer was relatively uncommon prior to the introduction of mass-produced cigarettes around 1910.
Other Risk Factors

Although smoking is the main cause of atypia/cancer, other risk factors do exist.

• Viral infection of vocal folds, such as recurrent respiratory papillomatosis (RRP) and verrucous vulgaris, may be precursors to atypia/cancer. (For more information, see RRP-Papillomatosis.)
• The backflow of stomach fluids to the voice box/laryngeal area (reflux laryngitis) leads to inflammation and risk for cancer. Unlike the surface lining cells of the stomach, the surface lining of the voice box is highly sensitive to the acidity of stomach fluids. (For more information, see Reflux Laryngitis.)