What is Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)?
Nasopharyngeal carcinoma (NPC), also known as lymphoepithelioma, is a type of cancer that originates from the cell lining of the nasopharynx – the area that connects the nose to the throat. This type of cancer is particularly common in China, with varying rates of occurrence. In Southern China, incidence rates are high, with 15 to 50 out of every 100,000 people affected. However, the rates are lower in the white population and Northern China. The disease is believed to result from a combination of genetic factors and an infection with the Epstein Barr virus (a common virus that can occasionally lead to cancer).
What Causes Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)?
The cause of the disease is thought to be a combination of environmental elements, genetic characteristics, and an infection from the Epstein-Barr Virus (EBV). Environmental factors such as smoking and foods containing certain chemicals called nitrosamines have been thought to play a role, especially in the Western population.
Also, the genetic makeup of the groups of people who are most affected by the disease is an important factor, this is clearly seen by the high rate of the disease in the Chinese population. Lastly, having an EBV infection along with a genetic predisposition has been shown to be significantly connected to the disease.
Risk Factors and Frequency for Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
Nasopharyngeal carcinoma (NPC), a type of cancer, is most commonly found in Southern China, Malay, Indonesia, and Southeast Asia. This disease can occur anywhere, but it’s more common in these places. In areas where NPC is less common, fewer than 1 in 100,000 people have it. However, in places where it’s common, between 25 to 30 out of every 100,000 males and 15 to 20 out of every 100,000 females have it.
Signs and Symptoms of Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
The symptoms of the disease can vary from person to person, depending on which area it affects.
- Nasal symptoms: Around 80% of people with this disease experience nasal problems. These can include a blocked nose, nosebleeds, post-nasal drip, voice changes, and an altered sense of smell. The severity of the symptoms usually depends on the size and extent of any abnormal growths.
- Ear symptoms: Many people with this disease have ear-related complaints due to blockage of the Eustachian tube. This can lead to hearing loss, feelings of fullness in the ears, and ringing in the ears.
- Neurological symptoms: Less common are symptoms related to the brain, affecting 8% to 12% of patients. These are due to various cranial nerve involvements, most commonly with the abducens nerve that controls the movement of the eyes.
- Nodal involvement: One common sign is enlarged nodes in the neck. The nodes at the top of the back of the neck and the upper jugular area are usually first to be affected. Nodes above the collarbone are affected in advanced stages of the disease.
Symptoms related to distant spread of the disease, especially to the liver and lungs, are rare. It can sometimes be tricky to determine the original location of the disease if it has spread to the lungs. In such cases, a PET scan can be helpful. In some instances, the disease may be associated with dermatomyositis, a rare inflammatory disease that causes muscle weakness and skin rash.
Testing for Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
If your doctor suspects that you might have a rapidly dividing tumor that has spread to your liver or is causing your renal (kidney) health to worsen, they will conduct some initial tests. These usually involve checking your blood count and testing your liver and kidney function. These basic tests offer a first indication of any abnormalities.
One particular virus, known as the Epstein Barr virus, is often found to play a role in the development of this disease. To detect its presence and assess its impact, your doctor may order a test called a “serum IgA level” test. This test is important not only for diagnosing the disease but also for understanding its progression or prognosis.
In terms of imaging, multiple methods can be used to visualize and assess the tumor. A CT scan is recommended if your doctor needs to check for any invasion of the tumor into your bones or brain. This type of scan can clearly show a tumor that is growing from the top of the throat. However, due to potential radiation exposure, and its limitations in capturing soft tissue and nodal metastasis (spread of the disease to the lymph nodes), this may not be the first choice for all cases.
Instead, an MRI scan may be the preferred method. MRI scans are excellent at showing how far a tumor has spread into the muscles and lymph nodes. They don’t have the radiation risk that comes with a CT scan. They can easily visualize the size of the tumor and its local invasion.
A PET scan is another imaging option that your doctor might consider. It’s especially useful for checking how well you’ve responded to treatment and for monitoring any possible recurrence of the disease. PET-CT scans are also good at revealing the extent of distant metastasis because they scan your whole body. Still, for local spread, an MRI scan is generally the preferred choice due to its ability to provide a greater level of detail.
Beyond these studies, your doctor might also opt to do a direct examination of the tumor using a procedure called nasopharyngoscopy. This involves inserting an endoscope (a thin, flexible tube with a light and a camera on the end) into your nose to look at the size of the tumor and how far it has spread. This procedure also lets your doctor take a biopsy, a small sample of tissue from the tumor to be examined under a microscope. However, if the mass is too large, it might be too difficult to access the nasal passage for this procedure.
Treatment Options for Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
Nasopharyngeal carcinoma, which is a type of cancer that occurs in the nasopharynx (the part of the throat behind the nose), is primarily treated by radiation therapy when it is localized. This treatment method is highly effective because this type of cancer responds well to radiation. Surgery is typically only used in cases where the disease recurs, whereas for advanced stages of the disease, chemotherapy is used hand in hand with radiation.
Radiation Therapy
Radiation is the principal choice of treatment for this type of cancer when it is localized. It’s quite effective for all stages from stage I to stage IVA, except for cases where the cancer has spread far (distant metastasis). Since the nasopharynx is a small cavity and the cancer tends to spread quickly in the area, a certain intensity of radiation is necessary not only for the primary tumor, but also for the adjoining areas that are free from cancer.
A recent improvement in radiation therapy involves the use of a method called intensity-modulated radiotherapy (IMRT). In this method, a detailed image of the cancer area is obtained using CT scans and the radiation beam is focused precisely on the cancer, minimizing radiation exposure to healthy tissues.
Another approach is brachytherapy, where tiny radioactive objects are inserted into the tumor area to provide targeted radiation treatment. This method is particularly useful for localized tumors that haven’t spread towards the brain and helps to protect vital organs in the vicinity from damage.
Should the treatment fail or the cancer recur, radiation therapy is still used. Attention is paid to the sensitivity of the local tissue, the overall health of the patient, and the possible effects on critical organs in the area.
Chemotherapy
As well as being sensitive to radiation, nasopharyngeal carcinoma also responds well to chemotherapy. For advanced local disease, a combination of radiation and chemotherapy is typically used. This not only fights the disease, but also helps to reduce the size of the tumor. The most commonly used chemotherapeutic drug is cisplatin.
In cases where the cancer has spread to various separate parts of the body (distant metastasis), chemotherapy is the preferred choice of treatment. Again, cisplatin combined with another drug called 5-fluorouracil is generally used. Despite advances in treatment, however, the average survival rate in these cases is generally not more than a year.
Surgical Intervention
Surgery is usually only an option for rescue treatments when other methods have failed. This is because the nasopharynx is a small and difficult to access area, making surgery challenging and potentially inappropriate. In cases where the cancer recurs locally, surgical intervention might be considered. It can also be used when cancer has spread to a limited number of other parts of the body (distant oligo-metastasis) and will be used alongside radiation therapy and radio ablation.
The surgical procedure to remove the nasopharynx, called nasopharyngectomy, can be carried out using several methods. The choice of method depends on the surgeon’s expertise and the patient’s overall health. In cases where the cancer has spread extensively in the neck or cases of recurring cancer, a type of surgery called radical neck dissection might be considered as part of a rescue treatment.
What else can Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma) be?
When diagnosing nasopharyngeal carcinoma, a type of cancer that starts in the upper part of your throat behind your nose, doctors would consider various similar conditions. These conditions are sorted out into two categories based on their nature. These include:
Benign Conditions (non-cancerous):
- Nasopharyngeal polyposis (polyps or growths in the nasopharynx)
- Angiofibromas (noncancerous tumors primarily made up of blood vessels and connective tissue)
Malignant Lesions (cancerous):
- Lymphomas (cancer that begins in infection-fighting cells of the immune system)
- Salivary gland tumors (cancer starts in the glands that make saliva)
- Sinonasal carcinomas (cancer that starts in the nose or the sinuses)
- Malignant mucosal melanomas (rare type of melanoma that develops in the mucous membranes)
What to expect with Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
The 5-year survival rate for patients has significantly improved due to advancements in radiotherapy techniques. This improvement has significantly reduced death and illness related to the disease, lifting the reported 5-year survival rate from 20% to 40% to almost 70% in the past decade.
However, the traditional system for predicting the disease’s progression based on its location and size is not fully accurate or sufficient. To increase accuracy, the latest method (in its 8th edition) includes checking the patient’s EPV DNA status. Some studies also suggest other efficient ways to assess the disease’s stage and predict the treatment outcome, such as analyzing changes at the genetic level (miRNA and DNA methylation).
Possible Complications When Diagnosed with Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
Certain health issues can result from local problems in the body, such as blockages in the Eustachian tubes which cause a specific type of ear infection known as otitis media with effusion (OME). This can also lead to ongoing nasal congestion and issues with breathing freely. If a substantial growth causes blockage in the back of the throat, it may interfere with swallowing. Should this blockage be left untreated, it may eventually obstruct the airway. Furthermore, if the damage extends within the skull and begins to affect the nerves there, it can lead to lasting impairments even after treatment.
Common Health Issues:
- Blockage in Eustachian tubes leading to otitis media with effusion (OME)
- Persistent nasal blockages
- Impaired ability to breathe freely due to throat blockages
- Swallowing difficulties due to blockages in the back of the throat
- Potential airway blockage if previous conditions are left untreated
- Damage to nerves within the skull leading to lasting impairment even after treatment
Preventing Nasopharyngeal Carcinoma (NPC, Lymphoepithelioma)
People living in areas where the disease is common should be particularly watchful for symptoms. In addition, the population in western regions who are exposed to environmental factors linked to NPC, such as smoking, should be given information about the harmful effects of these factors. Moreover, people who have a genetic tendency to the disease and who experience repeated EBV infection should be especially wary of the disease. NPC refers to nasopharyngeal cancer, a rare type of head and neck cancer, and EBV refers to Epstein-Barr virus, which has been associated with certain types of cancer.
