Nasopharyngeal cancers start behind the nasal passages, from the part above the soft palate to the upper part of the throat. People with the condition often develop nodules in the neck, may have a feeling of fullness or pain in the ears, and hearing loss. Later symptoms include a runny nose, nasal obstruction, facial swelling and numbness. A biopsy is needed to make the diagnosis and imaging tests (CT, MRI, or PET) are done to assess the extent of the cancer. Treatment is based on radiotherapy and chemotherapy and, exceptionally, on surgery.

Nasopharyngeal cancer, also called nasopharynx, cavum or epipharynx, is a cancer of epithelial origin, which develops in the cells of the upper part of the pharynx, behind the nasal passages, from the part above from the soft palate to the upper part of the throat. Most cancers of the nasopharynx are squamous cell carcinomas, which means they develop in the squamous cells lining the nasopharynx.

Although nasopharyngeal cancer can develop at any age, it particularly affects adolescents and patients over the age of 50. Although rare in the United States and Western Europe, it is common in Asia and is one of the most common cancers among Chinese immigrants to the United States, especially those of South Chinese and Southern descent. -Asian. Nasopharyngeal cancer is rare in France with less than one case per 100 inhabitants. Men are more frequently affected than women.

Nasopharyngeal epithelial tumors have been classified by the World Health Organization based on the degree of differentiation of malignant cells:

• Type I: differentiated keratinizing squamous cell carcinoma. Rare, it is observed especially in regions of the world with very low incidence;
• Type II: differentiated non-keratinizing squamous cell carcinoma (35 to 40% of cases);
• Type III: Undifferenciated Carcinoma of Nasopharyngeal Type (UCNT: Undifferenciated Carcinoma of Nasopharyngeal Type). It represents 50% of cases in France, and between 65% (North America) and 95% (China) of cases;
• Lymphomas which represent approximately 10 to 15% of cases.

Other nasopharyngeal cancers include:

• adenoid cystic carcinomas (cylindromes);
• mixed tumors;
• adenocarcinomas;
• fibrosarcomas;
• osteosarcomas;
• chondrosarcomas;
• melanomas.
  

Several environmental and behavioral factors have been shown to be carcinogenic for humans in connection with nasopharyngeal cancer:

• Epstein-Barr virus: this virus from the herpes family infects lymphocytes of the immune system and certain cells in the lining of the mouth and pharynx. Infection usually occurs in childhood and can manifest as a respiratory tract infection or infectious mononucleosis, a mild disease of childhood and adolescence. Over 90% of people around the world have been infected with this virus, but it is generally harmless. This is because not all people with Epstein-Barr virus develop nasopharyngeal cancer;
• the consumption of large quantities of fish preserved or prepared in salt, or of food preserved by means of nitrites: this method of preservation or preparation is carried out in several regions of the world, and in particular in South-East Asia. However, the mechanism linking this type of food to the formation of nasopharyngeal cancer is not yet clearly established. Two hypotheses are put forward: the formation of nitrosamines and the reactivation of the Epstein-Barr virus;
• smoking: the risk increases with the amount and duration of tobacco consumption;
• formaldehyde: classified in 2004 among the carcinogenic substances proven in humans for cancer of the nasopharynx. Exposure to formaldehyde occurs in more than a hundred professional environments and a wide variety of sectors of activity: veterinary, cosmetics, medicine, industries, agriculture, etc.
• wood dust: emitted during wood processing operations (felling, sawing, grinding), machining of rough wood or reconstituted wood panels, transport of chips and sawdust resulting from these transformations, finishing of furniture (ginning). This wood dust can be inhaled, especially by people exposed in the course of their work.

Other risk factors for nasopharyngeal cancer are suspected in the current state of knowledge:

• passive smoking;
• Alcohol consumption ;
• consumption of red or processed meat;
• infection with papillomavirus (HPV 16).

A genetic risk factor is also identified by some studies.

Most of the time, nasopharyngeal cancer first spreads to the lymph nodes, resulting in palpable nodules in the neck, before any other symptoms. Sometimes a persistent obstruction of the nose or eustachian tubes can cause a feeling of fullness or pain in the ears, as well as hearing loss, on a one-sided basis. If the eustachian tube is blocked, fluid effusion can build up in the middle ear.

People with the disease may also have:

• a swollen face;
• a runny nose of pus and blood;
• epistaxis, that is, nosebleeds;
• blood in saliva;
• a paralyzed part of the face or eye;
• cervical lymphadenopathy.

To diagnose nasopharyngeal cancer, the doctor first examines the nasopharynx with a special mirror or a thin, flexible viewing tube, called an endoscope. If a tumor is found, the doctor then has a nasopharyngeal biopsy done, in which a tissue sample is taken and examined under a microscope.

A computed tomography (CT) scan of the skull base and magnetic resonance imaging (MRI) of the head, nasopharynx, and base of the skull are done to assess the extent of the cancer. A positron emission tomography (PET) scan is also commonly done to assess the extent of cancer and lymph nodes in the neck.

Early treatment significantly improves the prognosis for nasopharyngeal cancer. About 60-75% of people with early-stage cancer have a good outcome and survive for at least 5 years after diagnosis.

As with all ENT cancers, the different alternatives and the treatment strategy are discussed in the CPR in order to offer the patient a personalized treatment program. This meeting is carried out in the presence of the various practitioners involved in the care of the patient:

• surgeon;
• radiothérapeute;
• oncologist;
• radiologist;
• psychologist;
• anatomopathologiste;
• dentist.

Due to their topography and local extension, nasopharyngeal cancers are not accessible to surgical treatment. They are usually treated with chemotherapy and radiotherapy, which are often followed by adjuvant chemotherapy:

• chemotherapy: widely used, because nasopharyngeal cancers are chemosensitive tumors. The most widely used drugs are bleomycin, epirubicin and cisplatin. Chemotherapy is used alone or in combination with radiotherapy (concomitant radiochemotherapy);
• external beam radiation therapy: treats the tumor and lymph node areas;
• conformational radiotherapy with intensity modulation (RCMI): allows an improvement in tumor dosimetric coverage with better sparing of healthy structures and areas at risk. The gain in salivary toxicity is significant compared to conventional irradiation and the quality of life improved in the long term;
• brachytherapy or placement of a radioactive implant: can be used as a supplement after external irradiation at full doses or as a catch-up in the event of a small superficial recurrence.

If the tumor reappears, radiation therapy is repeated or, in very specific situations, surgery may be attempted. This is however complex because it usually involves the removal of part of the base of the skull. It is sometimes performed through the nose using an endoscope.