Summary
Pharyngeal cancers include all malignant tumors arising in the nasopharynx, oropharynx, or hypopharynx. These cancers are most commonly squamous cell carcinomas. Alcohol and tobacco use are the two most important risk factors and are responsible for the majority of cases. Other risk factors include certain viral infections, poor oral hygiene, and workplace-related exposures, such as radiation. The clinical presentation depends on the location of the tumor. Symptoms may include a growing cervical lump, persistent sore throat, dysphagia, or a change in the voice. Diagnosis is confirmed based on tissue biopsy, whereas the extent of spread is determined via imaging modalities like CT or MRI. Treatment usually requires a combination of surgery, radiation therapy, and chemotherapy.
Epidemiology
- Age: 50–60 years in nasopharyngeal cancer; approx. 55–70 years in oro- and hypopharyngeal cancer
- Sex: ♂ > ♀ 2 to 3:1
- Nasopharyngeal cancer is rare in the United States; most common in patients of Mediterranean and southern Chinese (including Hong Kong) descent
References:[1][2][3][4][5]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
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Risk factors
- Tobacco consumption
- Alcohol use
- Further risk factors: nitrosamine; consumption from salted/preserved foods, chronic iron deficiency, long-term consumption of carcinogenic food (e.g., aflatoxin), exposure to radiation
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Associations
- Nasopharyngeal carcinoma: EBV infection
- Oropharyngeal carcinoma: human papillomavirus infection
- Diseases causing atrophy of the mucosa (e.g., Plummer-Vinson syndrome)
References:[6][7]
Clinical features
- Usually asymptomatic for a long time .; first manifestation often swollen cervical lymph node(s)
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Nasopharyngeal cancer
- Painless lymphadenopathy
- Obstruction of the Eustachian tube: recurrent otitis media (may be accompanied by effusion); conductive hearing loss
- Unilateral nasal discharge, nosebleeds, impaired nasal breathing (due to obstruction)
- Infiltration of caudal cranial nerves → Garcin syndrome
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Oropharyngeal cancer and hypopharyngeal cancer
- Common early symptom: local lymph node metastases causing enlarged cervical lymph nodes
- Severe ear pain
- Foreign body sensation, dysphagia, sore throat
- Muffled voice
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Metastatic disease (see “Clinical features” in Oral cavity cancer above)
References:[6][8][9]
Diagnostics
- Panendoscopy with biopsy: visualization of the tumor and surrounding anatomy
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Histopathological examination (confirmatory test)
- Determines type, grade, and extent of the tumor
- Pleomorphic cells and mitotic figures are seen in tissue samples from lesions which have undergone neoplastic change (from dysplasia to SCC).
- CT or MRI imaging: assesses tumor infiltration depth and invasion of surrounding structures
References:[6][6][8]
Treatment
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Early or localized pharyngeal cancers
- Complete surgical resection of the tumor (preferred) or
- Radiation therapy
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Locally advanced pharyngeal cancers
- Induction chemotherapy , concurrent chemoradiation or radiation therapy
- Surgical resection only carried out if there is response to induction therapies, or if tumor has well-defined margins
- Additionally, excision of the cervical lymph nodes (neck dissection) may be indicated.
- If inoperable, or if the patient rejects surgery: primary radiotherapy or radio- and chemotherapy
References:[10]
Prognosis
- Poor prognosis since tumors are commonly discovered in late stages
- 5-year survival rate 64%
References:[3][6]