Hypopharyngeal Cancer

Synonyms and related keywords: pyriform sinus cancer, lateral pharyngeal wall cancer, posterior pharyngeal wall cancer, postcricoid cancer


INTRODUCTION

Background: Hypopharyngeal cancer is a term used for tumors of this subsite of the upper aerodigestive tract, and like most other subsite designations, this is an anatomic rather than pathophysiologic distinction 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). The larynx interjects into the hypopharynx anteriorly and is considered a separate structure.

Hypopharyngeal cancers often are named more specifically for their location, including pyriform sinus, lateral pharyngeal wall, posterior pharyngeal wall, or postcricoid pharynx.

Pathophysiology: As in other head and neck cancer sites, nearly all hypopharyngeal malignancies arise from the epithelium of the mucosa and, therefore, are squamous cell cancers. Premalignant mucosal lesions evolve into hyperproliferative lesions that develop the capacity to enlarge, invade local structures, invade lymphatics to spread to regional lymph nodes, and invade vascular channels to metastasize to other organs.

Frequency:

• In the US: All pharyngeal subsites accounted for approximately 8000 cases in 1999.

• Internationally: All pharyngeal subsites accounted for approximately 90,000 cases in 1999.

Mortality/Morbidity: Early-stage hypopharyngeal cancers tend to be asymptomatic; thus, most patients present with advanced disease and a poor prognosis.

• Prognosis varies with the stage. The 5-year survival with small (T1-T2) lesions is 50-60%, but with T3-T4 lesions or multiple node involvement, survival falls to 15-30%.

• Functional problems from the tumor and/or treatment can include swallowing dysfunction, recurrent aspiration pneumonias, neck fibrosis, facial edema, and pain. Laryngectomies often are needed, leading to permanent loss of voice and permanent tracheostomy.

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

Sex: US incidence shows an approximate male-to-female ratio of 3:1.

• Women have a higher incidence of postcricoid cancers related to nutritional deficiencies (Plummer-Vinson syndrome).

• 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.