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Hypopharyngeal cancer is a term used for tumors of a subsite of the upper aerodigestive tract, and like most other subsite designations, the distinction is anatomic rather than pathophysiologic within the group of head and neck malignancies. The hypopharynx is the region between the oropharynx above (at the level of the hyoid bone) and the esophageal inlet below (at the lower end of the cricoid cartilage). Embryologically, the larynx interjects into the hypopharynx anteriorly and is therefore considered a separate structure.

Hypopharyngeal cancers are often named for their location, including pyriform sinus, lateral pharyngeal wall, posterior pharyngeal wall, or postcricoid pharynx (see images below). Most arise in the pyriform sinus. In the United States and Canada, 65-85% of hypopharyngeal carcinomas involve the pyriform sinuses, 10-20% involve the posterior pharyngeal wall, and 5-15% involve the postcricoid area.

Frequency

Cancer that arises in the hypopharynx represents approximately 7% of all cancers of the upper aerodigestive tract. The incidence of laryngeal cancer is 4-5 times that of hypopharyngeal cancer. All pharyngeal subsites accounted for approximately 124,000 cancer cases worldwide in 2002.

An analysis of the Surveillance Epidemiology and End Results (SEER) database demonstrates that the incidence of hypopharyngeal cancers decreased 35% from 1975 to 2001. The mortality rate due to hypopharyngeal cancers also decreased by 30%. This epidemiologic change is believed to be due to a decrease in the initiation of cancer in the hypopharynx and does not necessarily reflect any improvement in survival due to treatment.

Race
African Americans have had an increasing incidence of cancers of all pharyngeal subsites since the early 1970s.

Sex
US incidence indicates an approximate male-to-female ratio of 3:1. Women have a higher incidence of postcricoid cancers related to nutritional deficiencies (Plummer-Vinson syndrome) than men. The prognosis for women generally is better than that for men.

Age
The incidence of hypopharyngeal cancer rises in people older than 40 years; it is rare in people younger than 30 years. The mean age at presentation is 65 years. Patients diagnosed with hypopharyngeal cancer are typically men aged 55-70 years with a history of tobacco use and/or alcohol ingestion.

Prognosis

The biological behavior of carcinoma of the hypopharynx differs greatly from that of carcinoma of the larynx. Carcinomas of the hypopharynx are usually poorly differentiated and patients are usually asymptomatic; early presentations are unfortunately uncommon. In fact, T1 N0 cases (see Staging in Workup) account for only 1-2% of all patients seen.

The Hypopharynx - Hypopharyngeal cancers

The hypopharynx represents one of the most lethal sites for SCC. Lymph node metastases are clinically evident at time of diagnosis in 70% to 80% of patients and are indicative of advanced disease. Bilateral and contralateral lymph node metastases occur in 10% to 20% of cases, particularly if tumors cross the midline of the hypopharynx. Primary tumor extension beyond the hypopharynx is common. Hypopharyngeal cancers are characterized by a propensity to spread submucosally to involve the oropharynx or esophagus. Ulcerated deep infiltration and skip areas are common. This leads to difficulties in adequately assessing the margins of the tumor and contributes to poor local tumor control, even with the addition of adjuvant radiation. The majority (more than 75%) of hypopharyngeal cancers arise in the pyriform sinus while 20% occur in the posterior pharyngeal wall. Postcricoid cancers are rare (less than 5% of hypoparyngeal cancers). Posterior pharyngeal wall cancers tend to grow superficially and only involve the prevertebral fascia in advanced lesions. Pyriform cancers spread early to other contiguous structures, such as the larynx, postcricoid area, thyroid gland, and thyroid and cricoid cartilages. Most pyriform sinus cancers arise along the medial wall followed by the lateral wall of the sinus. The postcricoid mucosa is contiguous with the apex of the pyriform and tumor can spread circumferentially to involve the entire lower hypopharynx. Because of the locale of hypopharyngeal cancers and their growth patterns and proximity to the larynx, surgical management often entails total laryngopharyngectomy. » »

How is hypopharyngeal cancer diagnosed?

Tests and procedures that are used to diagnose hypopharyngeal cancer include:

Endoscopy - This procedure uses a thin, lighted tube that is inserted into the nose or mouth to check for anything unusual.
Physical exam - Doctors check for swollen lymph nodes in the neck and look down the throat with a small mirror to check for anything unusual.
CT scan (also called computed tomography or computerized tomography) - This scan takes a series of detailed pictures of areas inside the body. The images are created by a computer that is linked to an X-ray machine.
MRI (also called magnetic resonance imaging) - This procedure uses radio waves and a powerful magnet, linked to a computer, to create detailed pictures of areas inside the body.
Esophagoscopy - This procedure looks inside the esophagus to check for unusual areas. An esophagoscope (a thin, lighted tube) is inserted through the mouth and down the throat into the esophagus. Tissue samples might be taken for biopsy. This is usually done under general anesthesia or heavy sedation.
Bronchoscopy - This procedure looks for unusual areas inside the trachea and large airways of the lung. A bronchoscope (a thin, lighted tube) is inserted through the nose or mouth into the trachea and lungs. Tissue samples might be taken for biopsy. This is usually done under general anesthesia or heavy sedation.
Biopsy - In this procedure, tissue samples are removal and viewed under a microscope to determine if cancer is present.