Nasopharyngeal Cancer

What is Nasopharyngeal Cancer?

The pharynx is a tube-like structure linking your nose to your windpipe, or trachea. The nasopharynx, or the upper portion of the pharynx, is encircled by various structures, it’s the back part of your nose. It’s surrounded by the back area of your nasal cavity in front and by a part of mucous membrane (the layer that covers the throat) at the back. On the sides, it’s limited by the small openings of a tube that connects the throat to the ear and other structures such as the Fossae of Rosenmuller, also known as a natural space or indentation. Above, it’s surrounded by a bone in your skull (the sphenoid), and below, it’s linked to the soft part of the roof of your mouth, or the soft palate.

Cancers originating from this area are most commonly a type called squamous cell carcinoma. They may behave differently from other squamous cell carcinomas in the head and neck and have distinctive risk factors and causes. The Fossae of Rosenmuller, the indented area on the side, is where most of these nasopharyngeal cancers can be traced back to.

There are certain geographic and ethnic risk factors for developing nasopharyngeal cancer. It’s greatly widespread in Asia, particularly in China, and having Chinese ancestry is a risk factor no matter where a person lives. People of Native Alaskan heritage also show a higher occurrence of this type of cancer.

Many cases in high-risk areas can be linked to an infection with the Epstein-Barr virus (EBV), although it’s a common virus that most people have, which makes it difficult to understand exactly how it causes the disease. Specific parts of the virus have been shown to play a significant role. Nasopharyngeal cancers associated with the human papillomavirus (HPV) have been reported too, but no direct link has been established as yet.

Nasopharyngeal cancers behave differently based on their histological subtype, or their specific characteristics when viewed under a microscope. The World Health Organization (WHO) tracks three subtypes of this type of cancer. The first is linked to EBV infection in 70% to 80% of cases. The second and third subtypes (type 2 and type 3) are the most common and are also the most responsive to treatment. These two mostly occur where EBV infections are common. If the cancer shows basaloid features, which involves different types of cells, it is a rare aggressive subtype.

Treatment depends on the cancer stage and usually doesn’t involve surgery. However, radiation therapy could be used for early stages, while chemotherapy may be used for late stages. New treatment methods include using immunotherapy, which uses the body’s immune system to fight cancer, targeting certain proteins related to the virus.

Over the past ten years, the death rate due to nasopharyngeal cancers has decreased, thanks to early detection and advancements in treatment. This progress highlights the importance of continued research and innovative approaches in managing nasopharyngeal cancer.

What Causes Nasopharyngeal Cancer?

The exact cause of nasopharyngeal carcinoma, a type of cancer that occurs in the upper part of the throat behind the nose, is not completely known. It’s likely due to a mix of inherited genes, environmental influences, and viral factors. In places like the US, where a virus called Epstein-Barr virus (EBV) is not common, habits like smoking and drinking alcohol have been identified as risk factors for nasopharyngeal carcinoma. However, in areas where EBV is common, this doesn’t seem to be the case.

Around the world, especially in Asia, different kinds of this cancer are associated with the Epstein-Barr virus, but not all. For instance, WHO type 1 tumors seem to be more variable and unrelated to EBV, while WHO type 2 and 3 tumors are definitively linked to EBV.

Other risks for getting nasopharyngeal carcinoma include being of Asian descent, particularly Chinese, even outside of Asia. This is why people of Native Alaskan descent who share common ancestors with Asians might also have a higher risk . Some eating habits, like consuming preserved foods with nitrosamines (especially salted fish), might also heighten the risk.

Studies have shown that in some areas, both where EBV is common and where it’s not, nasopharyngeal cancer can run in families. This implies that inherited genes and environmental factors likely play a role in causing this disease. In some EBV common places, tracking circulating EBV DNA is used to check for the disease and ongoing follow-up care. High levels of circulating EBV in the body are linked with worse responses to treatment, and higher chances of cancer spreading and causing death. While more research is needed, persistently high levels of EBV after treatment have been pointed out as a strong predictor of poor survival chances.

Risk Factors and Frequency for Nasopharyngeal Cancer

Nasopharyngeal carcinoma, a type of throat cancer, is more common in certain parts of the world. In the Americas and Europe, where the disease is not common, there are less than 1 case per 100,000 people. On the other hand, areas like certain parts of China have a higher incidence rate of up to 21 cases per 100,000 people, making up 18% of all cancers there. The disease typically occurs in middle-aged individuals in Asia, while in Africa, it’s most commonly observed in children.

The age at which the disease typically appears varies in different areas. In the Americas and Europe, the disease tends to appear either in the late teenage years or between the ages of 60 and 70. There’s also a gender-based disparity, with men being 2.75 times as likely to develop nasopharyngeal carcinoma and 3.25 times as likely to die from it as women. This could potentially be due to different patterns of tobacco use, as smoking is more common among men in areas where the disease is most common, like China. Some evidence also suggests that people over the age of 55 have equally high risk and mortality rates, regardless of gender.

• Location: Rates of nasopharyngeal carcinoma vary globally. In nonendemic areas like the Americas and Europe, it’s rare. Contrastingly, areas such as certain parts of China experience a much higher incidence.
• Age: The typical age of patients varies. In Asia, nasopharyngeal carcinoma commonly affects middle-aged individuals, whereas in Africa, it’s observed more in children.
• Gender: Men have a higher risk of developing and dying from nasopharyngeal carcinoma as compared to women. The reason behind this discrepancy is still unclear but might be related to different tobacco use patterns.

Signs and Symptoms of Nasopharyngeal Cancer

Nasopharyngeal cancer, a type of head and neck cancer, often shows symptoms in its advanced stages. Most people only discover they have it when they find a lump in their neck. The lump is usually painless and can be discovered accidentally. If an adult has a new lump in their neck for over two weeks, they should get it checked out immediately, as it may indicate something serious like cancer. Questions about the size of the lump, when it was first noticed, whether there have been any recent infections, and if there are any other lumps in the neck are important to discuss with a healthcare professional.

Other symptoms that may point to nasopharyngeal cancer need to be discussed too. If you’ve experienced changes in your voice, have trouble swallowing or pain when swallowing, ear pain, nasal blockage, nosebleeds, coughing up blood, vomiting blood, changes in vision, headaches or face pain, or constant runny nose, let your healthcare provider know.

Your lifestyle and personal history matter as well. If you’ve used tobacco or alcohol, been exposed to the sun regularly, whether for work or leisure, how much you use sunscreen, and what kind of job you have could all be factors. Your family history and ethnicity, especially if you’re from an Asian background, is also useful information. And of course, tell your healthcare provider if you’ve had any history of cancer in the head and neck region, skin cancer, or any weakening of your immune system.

A thorough physical examination covering your head and neck region is important. This includes checking your skin and scalp for noticeable or touchable cut or swellings and figuring out if any scars are from past cancerous or precancerous lesion removals. Your ears will be checked for fluid buildup, focusing on one-sided buildup as that may point to a blockage in the adult nasal area.

• A close look at the inner part of your nose can reveal visible lesions and might be conducted before and after a decongestant is used
• A deep examination of your nasal area through a procedure known as nasal endoscopy
• In adults, prominent or asymmetrical adenoids (lymph tissue in the back of the nasal cavity) are worrying
• About your mouth and the back of your mouth, the focus will be on the state of your oral mucosa, teeth, and by touching to feel for any abnormalities of your tongue, the base of your tongue, and the floor of your mouth
• The tongue base, the back and bottom parts of your mouth, would be thoroughly inspected through a flexible laryngoscope
• If there are any lumps or lymph gland enlargement, thyroid nodules, and signs of stridor or hoarseness should be carefully noted during the neck examination
• An examination of cranial nerves is critical for identifying any deficiencies or asymmetries

Testing for Nasopharyngeal Cancer

If you ever have problems with your head or neck, the first thing doctors do is make a note of all your symptoms and conduct a detailed physical examination. If a potential tumor or suspicious lump is found in areas like your mouth, throat, thyroid gland, or the part of your throat that leads to the food pipe, chances are your doctor will recommend a CT scan with a dye injected into your vein to get a better view of your neck region.

For lumps found in the area behind your nose and above your mouth, the best type of scan to use has been a topic of much discussion. Historically, CT scans with a dye have been favored for initial investigations. CT scans are great at showing if the bone has been affected, checking nearby lymph nodes (small, bean-like structures that produce and store cells that fight infection), and they are often required for planning radiation therapy treatment. However, they aren’t the most accurate when looking at how much the tumor has grown into the surrounding soft tissues, and they might not be able to pick up very tiny tumors. In such cases, MRI scans or a combination of PET and CT scans could be more beneficial.

Practical reasons like availability or insurance requirements often make CT scans the first choice, especially when patients can’t have an MRI due to metal implants or discomfort in small, enclosed spaces. If a CT scan is used, getting images sliced as thin as 1 to 2 millimeters of the region behind the nose is crucial for the best evaluation of the suspected tumor and the holes in the base of the skull that allow nerves to pass through.

An MRI scan of the face and neck is the best way to see how far the tumor has grown with great precision. It’s better than other scans at finding tumors that can’t be seen during an internal examination or with CT scans. While CT scans are also effective at looking at neck lymph nodes, an MRI is considered a valid alternative. For cancers that spread, a PET scan is often recommended, as these cancers tend to metastasize (spread to other parts of the body) and PET scans can find lymph node metastases that have not yet been clinically diagnosed.

To make the right treatment decisions, it’s crucial to figure out the type of the tumor. This can be done by taking a sample of the tumor through an endoscopic biopsy, a procedure done with a small camera through a long, thin tube. The procedure can be done under local or general anesthesia. If the primary tumor can’t be located easily, a needle biopsy of the swollen neck lymph node could be done for cytology (study of cells) and EBV (Epstein-Barr Virus) testing. An EBV-positive node metastasis often means that the cancer originated from behind the nose, which helps doctors with staging, prognosis, and treatment decisions, even if they can’t see the original tumor.

Standard care for patients includes a team of various specialties, typically including medical oncology, radiation oncology, surgical oncology, radiology, and pathology. It’s this collaborative approach that ensures effective treatment planning and patient care.

Treatment Options for Nasopharyngeal Cancer

Most cases of nasopharyngeal cancer, which happens in the upper part of the throat behind the nose, are typically treated without surgery. This is because the cancer is often found in the late stages, where it has spread to bony structures that can’t be removed safely. Additionally, the location of this cancer makes surgical access difficult. However, in rare cases where the cancer is small and hasn’t spread, surgery might be considered using a surgical method involving a scope or through the palate (roof of your mouth).

For patients whose initial chemotherapy and radiation treatments have not worked, surgery can be used in some cases. However, surgery for nasopharyngeal cancer is considered a highly specialized approach and is not used often.

Typically, the non-surgical treatment options for nasopharyngeal cancer include radiotherapy (use of high-energy rays to kill cancer cells), chemotherapy (use of drugs to destroy cancer cells), or a combination of both, depending on the stage of the cancer.

Radiotherapy is the primary treatment method for this type of cancer. This treatment helps control the cancer while minimizing harm to structures nearby like the eyes, brain, middle ear, and jaw joint. For early-stage nasopharyngeal cancer, radiotherapy is the only treatment used, while chemotherapy is added for more advanced cases. The focus of radiotherapy is the nasopharynx and the surrounding lymph nodes, those small glandular structures that filter fluids in the body, which are at risk of cancer spread.

The cancer often spreads through lymph nodes in the neck. Unless the disease is in the very early stage, these lymph nodes have to be treated too. However, the dosage of radiotherapy can be reduced to minimize harm to surrounding structures.

When it comes to chemotherapy, this can significantly improve the survival rate for patients with stage III and locally advanced stage IV nasopharyngeal cancer when combined with radiotherapy. The choice of chemotherapy depends on the patient’s cancer stage and condition. The commonly used chemotherapy drug for nasopharyngeal cancer is cisplatin. If the patient can’t tolerate cisplatin, some alternative treatment options are available.

In case the initial treatment fails, research to reduce the harmful effects of radiotherapy to surrounding structures is ongoing. Some trials have shown promising results using lower dosage radiotherapy and pre-treatment with chemotherapy, particularly in children where the long-term effects of facial radiotherapy are significant.

What else can Nasopharyngeal Cancer be?

An accurate diagnosis of nasopharyngeal carcinoma (throat cancer) can sometimes be challenging because a number of other conditions can show similar symptoms. Those conditions include:

• Enlarged adenoids/HIV-associated lymphatic growth
• Antrochoanal polyp (a noncancerous growth in the nose)
• Inverted papilloma (a type of nasal tumor)
• Vascular malformation (abnormal blood vessels)
• Other forms of cancer
• Nasal polyposis (nasal polyps)
• Infectious mononucleosis (commonly known as mono or the “kissing disease”)
• Non-Hodgkin lymphoma (cancer that originates in the lymphatic system)
• Sarcoma (cancer that begins in the bones and soft tissues)
• Adenocarcinoma (cancer that originates in glandular cells)
• Wegener granulomatosis (an uncommon disorder that causes inflammation of blood vessels)
• Rhinosporidiosis (a rare, chronic infection that usually affects the nose and nasal passages)

What to expect with Nasopharyngeal Cancer

The survival chances of a patient with nasopharyngeal carcinoma, a type of cancer that starts in the upper part of your throat, heavily depend on the stage of the cancer when it’s diagnosed. The earlier the stage of the disease, the better the chances of survival. Stage I, which is the earliest stage, has a survival rate of about 82% over 5 years, meaning this many people are alive five years after diagnosis. However, as the disease progresses to later stages, chances of survival decrease, with stage IV, the most advanced stage of the disease, having a survival rate of 49%.

After the initial treatment, patients should have regular check-ups with their cancer specialist. These check-ups usually involve physical examinations, nasal endoscopy (a procedure where a thin, flexible tube with a light at the end is inserted into your nose to examine your nasal area), and possibly blood tests for EBV DNA and thyroid function. They need to look for EBV DNA, a part of the virus that’s linked to this type of cancer, because if it’s found after treatment, it usually means the prognosis isn’t great. They also check your thyroid function since thyroid issues can arise after radiation therapy.

At most healthcare centers, patients usually undergo a PET-CT scan, which is a kind of imaging test that can check if the cancer is still there, 3 months after their radiotherapy treatment is done. If this scan looks normal, you’ll probably have another one a year after treatment. After these two scans, if both are negative – which means they don’t see any cancer – more scans may not be necessary especially in areas where nasopharyngeal carcinoma is not common. However, keep in mind that this is not an absolute rule as individual circumstances and new research findings can change how doctors recommend follow-up schedules.

Possible Complications When Diagnosed with Nasopharyngeal Cancer

Nasopharyngeal carcinoma, a type of cancer that occurs in the nasopharynx (part of your throat behind the nose), and its treatments can result in a range of complications.
Here are some of the complications associated with nasopharyngeal carcinoma:

• Radiation therapy side effects: Treatment like radiation therapy may cause issues like mucositis (painful inflammation and ulceration of the mucous membranes), xerostomia (dry mouth), skin irritation due to radiation (radiation dermatitis), and tiredness.
• Chemotherapy side effects: Chemotherapy, another treatment process, can cause nausea, vomiting, tiredness, hair loss, and a higher risk of getting infections.
• Weakened immune system: Both cancer and its treatments can make your immune system weaker, which makes you more prone to infections.
• Long-term xerostomia: A persistent dry mouth due to reduced functioning of salivary glands is often caused by radiation therapy. This could lead to difficulties in swallowing and speaking and increase the risk of dental problems.
• Hearing loss: If the tumor is located near specific structures or is extensive, hearing loss may occur.
• Cognitive problems: Radiation therapy to the head and neck may affect mental function, such as memory and attention.
• Metastasis and recurrence: Nasopharyngeal carcinoma can spread to distant organs in your body. Also, even after treatment, the cancer may come back in the original location, which may need further treatments.
• Secondary cancers: People who have had nasopharyngeal carcinoma and survived long-term, might be at higher risk of getting other cancers, often related to the treatment they received.

Preventing Nasopharyngeal Cancer

To prevent nasopharyngeal carcinoma, a type of cancer that occurs in the upper part of the throat behind the nose, it’s crucial to educate individuals on the various elements relating to the disease. This includes ensuring that people are aware of critical factors that can increase the risk of developing this condition, such as infection with the Epstein-Barr virus (EBV), a common virus that can in some cases lead to cancer, genetic predispositions, and living in certain geographic areas.

People are often encouraged to avoid behaviors known to increase the risk of nasopharyngeal carcinoma, such as using tobacco products or drinking too much alcohol. Adopting a healthier lifestyle can also help lower the risk, with suggestions including eating a balanced diet and getting regular physical exercise.

Early detection is key to effectively treating this cancer, so regular health checks and screenings are recommended. We also make sure to inform the public about the symptoms of this disease to help with early detection. While this cancer is more common in specific regions and among certain ethnic groups, we educate about these specific risks and urge those who may be at a higher risk to seek medical care quickly.

Besides, we raise awareness on how to prevent the spread of the EBV virus which includes maintaining good hygiene practices. Genetic counselling is available for people with family history of this cancer. Regular health checks are strongly encouraged and we provide information about different treatment options, possible side effects and the likely outcomes one can expect.