Nasopharyngeal Carcinoma

What is Nasopharyngeal Carcinoma?

Nasopharyngeal carcinoma (NPC), also known as lymphoepithelioma, is a specific type of cancer that originates from the cells lining the upper part of the throat behind the nose – an area known as the nasopharynx. This type of cancer is the most common one affecting the nasopharynx. Even though it can be found everywhere in the world, it mainly affects people in parts of Asia and Africa.

The rate at which it occurs varies significantly. For example, in the southern part of China, it can affect between 25 to 50 people out of every 100,000. Conversely, in European populations, it affects only about one person out of every 100,000. This variation is believed to be caused by a combination of genetic factors and infection with the Epstein-Barr virus (EBV). Notably, this disease is more common in men.

What Causes Nasopharyngeal Carcinoma?

The causes of the disease involve a mix of things from our environment, our genetic makeup, and infection from the Epstein-Barr virus (EBV). Certain behaviors or exposures in our surroundings, like smoking, heavy alcohol drinking, and eating foods that contain nitrosamines (a type of chemical compound) can increase our risk.

Your genetics can also play an important role. This is shown by how common the disease is in the Chinese population, where it accounts for up to 18% of all cancers in some areas in southern China and Taiwan. This indicates that certain ethnic groups might be more susceptible due to their genetic structure.

Finally, infection with the Epstein-Barr virus (EBV), especially when it occurs in people who are already genetically prone to the disease, has been found to be significantly linked to the disease.

Risk Factors and Frequency for Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is commonly found in southern China, Southeast Asia, and Africa. The occurrence of this disease greatly varies. In areas where it’s not common, there are usually less than one case per 100,000 people. However, in areas where the disease is common, it’s quite different. There are typically 25 to 50 cases per 100,000 males and 15 to 20 cases per 100,000 females.

Signs and Symptoms of Nasopharyngeal Carcinoma

The symptoms of a disease can vary greatly depending on where it develops. In the case of nasopharyngeal carcinoma (NPC), the most common area where these tumors originate is on the side of the throat behind the nose, in an area known as the fossa of Rosenmuller.

Here are some common symptoms that patients might experience:

• Nasal symptoms: Around 80% of people with NPC experience nasal symptoms. These can include a blocked nose, nosebleeds, a constant need to clear the throat, changes in voice due to nasal obstruction, or an abnormal sense of smell. The severity of these symptoms usually depends on the size of the tumor and how much it has spread.
• Otological symptoms: Patients might also have symptoms related to their ears, usually because the tumor is blocking their eustachian tube, a tube that connects the middle ear to the throat. These symptoms can include hearing loss, fluid build-up in the middle ear, or a sensation of fullness in the ear. Unilateral middle ear effusion (fluid build-up in one ear) in adults warrants checking the throat area to exclude the possibility of a tumor. About half of the NPC patients have some ear-related symptom, usually due to the tumor blocking the outflow from the eustachian tube.
• Neurological symptoms: Between 8% to 12% of patients present with symptoms related to the spread of the tumor into the brain. This could lead to different forms of cranial nerve involvement, each producing specific symptoms. Cranial nerve palsy (weakness or paralysis of the cranial nerves) is found in 20% of NPC patients and can be the presenting symptom. The abducens nerve, which controls eye movement, is the most commonly involved.
• Nodal involvement: One common symptom in NPC patients is an enlarged lymph node in the neck. The lymph nodes at the top of the back of the neck and near the throat are typically the first to be involved, along with the lymph nodes situated behind the throat. The lymph nodes above the collarbone are usually the last to be affected and this indicates an advanced stage of the disease.
• Distant metastasis and paraneoplastic syndrome: Symptoms related to the spread of cancer to distant parts of the body are rare initially. The most common places it can spread to are the liver and lungs. Usually, a PET scan helps in identifying and differentiating the primary tumor site, especially when lung lesions occur. In some cases, people may exhibit symptoms of dermatomyositis, which is a rare inflammatory disease that can occur in sync with NPC.

Testing for Nasopharyngeal Carcinoma

When it comes to understanding your healthcare needs more clearly, a number of lab tests may be recommended depending on your situation. Basic tests, like a complete blood count, and kidney and liver function tests can provide key information about the overall health of your body. These tests might be ordered when there is a concern for cancer spread (metastasis) or other diseases connected to cancer (paraneoplastic syndrome).

There’s another test related to the Epstein-Barr Virus (EBV) that checks levels of a specific type of immune protein called IgA in your blood. This test can help in making a diagnosis and assessing the severity of the disease, particularly in areas where the disease is more common.

Nasopharyngeal carcinoma, or cancer occurring in the part of your throat just behind your nose, often requires imaging tests to understand its extent. Computed tomography (CT scan), which takes detailed pictures of the inside of your body, can be helpful in assessing whether the cancer has spread to bones or other soft tissues. It is particularly useful in checking cervical nodes – small glands located in your neck. This process usually involves injection of a contrast dye to highlight specific areas more clearly.

Magnetic resonance imaging (MRI) is another type of imaging technique used to visualize the structures and tissues within your body. It’s typically the recommended option to understand if the cancer has spread towards your brain, involved your cranial nerves – the nerves running from your brain to various parts of your head and neck, and affected your sinuses. MRI is also great at showing detailed images of soft tissues like muscles. It has the added advantage of not using any radiation.

A test known as a PET scan is used to find out whether your treatment has been successful, or to check for any signs of recurrence of the condition. This test is common when cancer is first diagnosed, to check if it has spread to other areas of the body.

When it comes to diagnosing and understanding nasopharyngeal carcinoma better, an endoscopic evaluation and biopsy may be suggested by your specialist. Endoscopy involves inserting a small tube with a camera attached into your nasal passage to look directly at the affected area. Biopsy means taking a small tissue sample for further examination under a microscope. In some cases, other areas like your cervical nodes might also need to be biopsied via a method called fine-needle aspiration which involves the use of a very thin needle.

Treatment Options for Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma, or NPC, is primarily treated with radiation therapy, and sometimes combined with chemotherapy for advanced-stage diseases. Surgery is only used in rare cases for very small primary tumors or small recurrences because it can have a higher risk of complications compared to radiation therapy.

Radiation therapy is the preferred type of treatment for NPC. NPC frequently spreads to the lymph nodes in the neck, which is often an initial symptom. The tumor also grows locally (around the nose and throat) sometimes with little to no symptoms. One of the recent improvements in radiation therapy is called intensity modulation, or intensity-modulated radiotherapy. This method targets the area of the tumor with precision with the help of a CT, which takes images of the affected area.

Another method called brachytherapy involves implanting tiny capsules containing radiation into the tumor. However, this method isn’t very common today due to the introduction of intensity-modulated radiotherapy. Radiation therapy is also used for NPC when it comes back. But repeating radiation to the same area with the intention of curing it, often depends on the time interval between the first treatment and recurrence. It’s also used for pain relief.

In cases of advanced local diseases, combining chemotherapy with radiation therapy is often the best course of action. The most common medicine used in chemotherapy for NPC is cisplatin. Additionally, when the cancer has spread far from the origin, chemotherapy is the preferred option. When the NPC has spread to many places in the body, palliative chemotherapy (aimed at relieving symptoms and improving quality of life) is usually the choice. Drugs like cisplatin and 5-fluorouracil are commonly used. Regardless of advancements, the average survival rate remains no more than a year for patients with widespread metastases.

Surgery is primarily used as a last resort option. The nasopharynx (the area behind your nose at the top of your throat) is small and hard to reach, which makes the surgical approach challenging and sometimes unsuitable. But if the NPC recurs locally, patients should be given the option of surgery. The surgery, called nasopharyngectomy, can be done in several ways, but the method should be fitted to the surgeon’s skills and the patient’s overall health. The techniques include:

• Inferior approach through a cut across the palate.
• Lateral approach through the side of the skull base.
• Inferolateral approach.
• Midfacial degloving.
• Endoscopic approach.

In combination with these procedures, neck dissections are also performed, especially when the neck is extensively involved. Neck dissection is often a part of surgical salvage, particularly in the case of regional recurrence.

What else can Nasopharyngeal Carcinoma be?

When a doctor is trying to diagnose nasopharyngeal carcinoma (a type of cancer in the area behind the nose), they would consider other benign (non-cancerous) and malignant (cancerous) conditions that might cause similar symptoms. These include:

Benign conditions:

• Nasopharyngeal polyposis (polyps or growths in the nose)
• Angiofibromas (non-cancerous tumors in the nose)
• Antro-choanal polyp (tumor that originates in the maxillary sinus)
• Inverting papilloma (a type of non-cancerous growth in the nasal cavity)
• Adenoid hypertrophy (overgrowth of the adenoids)
• Thornwaldt cyst (a benign cyst in the nasal area)
• Encephalocele (a neural tube defect that causes the brain tissue to come out from an opening in the skull)

Malignant conditions:

• Lymphoma (cancer of the lymphatic system)
• Sarcoma (cancer that affects various tissues in the body)
• Mucosal melanomas (a rare form of cancer that grows in the mucous membrane that lines the nose, mouth, and other areas)

By considering these possibilities, doctors can make an accurate diagnosis.

What to expect with Nasopharyngeal Carcinoma

The general outlook and the survival rate over five years have gotten better thanks to advancements in radiation therapy techniques. These improvements have led to a significant rise in the reported five-year survival rates. In the past, this rate used to range between 25% and 40%, but it has increased to about 70% in the current era of treatment.

Possible Complications When Diagnosed with Nasopharyngeal Carcinoma

The biggest issue stemming from Eustachian tube blockage is the development of a middle ear infection, known as otitis media with effusion. Other possible complications can include ongoing nasal blockage and obstruction of the oropharyngeal airway, which is the part of the throat right behind the mouth. A severe problem involves the infection spreading to form inside the skull and affect the cranial nerves. This could lead to ongoing disability, even after treatment. There might be lasting damage as it is not always possible to restore the cranial nerve’s function, even after the root cause has been addressed. If more than one cranial nerve is affected, that is usually a bad sign for the patient’s overall outlook.

Common Complications:

• Otitis media with effusion due to Eustachian tube blockage
• Persistent nasal blockage
• Obstruction of the oropharyngeal airway
• Intracranial extension of the infection
• Involvement of cranial nerves
• Potential lifelong disability due to cranial nerve damage

Preventing Nasopharyngeal Carcinoma

People living in areas where a certain disease is common should be extra watchful for its symptoms. Additionally, folks living in Western countries who are exposed to conditions like smoking – which can increase the risk of getting Nasopharyngeal Carcinoma (NPC), a type of cancer that starts in the upper part of the throat – should be educated about these dangerous effects. Furthermore, anyone who is genetically more likely to get this disease and has had repeated infections with Epstein-Barr Virus (EBV), a common virus that can also cause certain types of conditions, should be on the lookout for signs of the disease.