Nasopharyngeal carcinoma (also called NPC, nasopharynx cancer or Cantonese cancer) is a head and neck cancer more frequently seen in Asia. In 2018, there were 831 new cases of nasopharyngeal carcinoma in Hong Kong, accounting for 2.4% of all new cancer cases. Fortunately, the incidence rate per 100,000, which is 3 times higher for men, dropped an average of 50% between 1983 and 2018. Although it is hardly noticed early, the chance to cure nasopharyngeal carcinoma is high at an early stage.
What is Nasopharyngeal Carcinoma?
Nasopharyngeal carcinoma is a malignant tumor occurring in the nasopharynx, which is located at the very back of the nose and above the back of the throat. Carcinoma is the most common type of cancer. They are abnormal cells that make up the skin and organ tissues growing out of control. Carcinomas may spread to other parts of the body (metastasis) to cause other problems and form new cancer. Nasopharyngeal carcinoma is hard to be detected not only because of its hidden location, but also because most nasopharyngeal carcinoma symptoms mimic other common conditions.
Signs and Symptoms of Nasopharyngeal Carcinoma
In the early stage, nasopharyngeal carcinoma symptoms may not be obvious. However, when the tumor grows and spreads into the surrounding tissues, you may start to notice the following signs and symptoms:
Causes and Risk Factors of Nasopharyngeal Carcinoma
Although the exact cause of nasopharyngeal carcinoma is not known yet, it is thought to be related to diets, infections, and heredity. The following risk factors may contribute to the cause of nasopharyngeal carcinoma, though it does not mean that you must develop the disease even if you have many or all the following risk factors:
- Sex: Nasopharyngeal carcinoma is more commonly seen in males than females.
- Race: Asians have a higher risk of developing nasopharyngeal carcinoma.
- Infection: Epstein-Barr virus (EBV) infection is very common worldwide and mainly occurs in childhood. In most patients with nasopharyngeal carcinoma, high levels of EBV antibodies are found in their blood, which is evidence of EBV infections. However, the link between EBV infection and nasopharyngeal carcinoma is not fully understood. Many factors may contribute to their relationship, such as genes.
- Diet: The reason why nasopharyngeal carcinoma is more common in Asia, especially Southern China and Hong Kong, maybe due to the predilection for salt-cured foods, such as salty fish and pickled vegetables. Consuming too many chemicals in these foods may be related to nasopharyngeal carcinoma.
- Family history: Having a first-degree relative (including parents, siblings, and children) with nasopharyngeal carcinoma or other cancers may imply a higher chance of developing nasopharyngeal carcinoma or other cancers.
- Lifestyle: Smoking tobacco and abusing alcohol increase the risk of nasopharyngeal carcinoma.
How to Prevent Nasopharyngeal Carcinoma?
Unfortunately, the association between nasopharyngeal carcinoma and the above said risk factors is not completely understood. People who develop nasopharyngeal carcinoma can have no risk factors. Nonetheless, some of the risk factors can still be controlled, such as the consumption of salt-cured foods. In addition, it is recommended to have a regular checkup, particularly when you have a family history of nasopharyngeal carcinoma. Also, you should seek medical advice as soon as possible if you experience symptoms like swollen neck lymph nodes. The earlier you discover, the more successful you prevent and treat nasopharyngeal carcinoma.
Tests for Nasopharyngeal Carcinoma Diagnosis
Since the nasopharynx is hard to be examined, proper examination by an oncologist or otolaryngologist with corresponding equipment is recommended. The following diagnostic tests may be taken to test and diagnose nasopharyngeal carcinoma:
- Physical examination: Your doctor may ask you some questions about possible risk factors and family history. Also, the doctor may pay special attention to the symptoms of the nose, mouth, throat, and neck. A hearing test is also required sometimes.
- Endoscopy: A nasal endoscopy (nasopharyngoscopy) involves the use of a special instrument called nasopharyngoscope to check for any abnormality in the nasopharynx. This procedure usually requires local anaesthesia.
- Biopsy: If any abnormalities are found, the most reliable way to confirm the diagnosis of nasopharyngeal carcinoma is to extract some biopsy for pathological testing.
- Blood test: EBV antibodies and EBV DNA in the blood may be used as indicators for diagnosing nasopharyngeal carcinoma.
After the physician has confirmed the diagnosis, other tests (mainly imaging tests) are needed to see if cancer has spread to other parts of the body, especially the lung. Tests that can determine the extent and stage of cancer include:
- Chest X-ray
- Magnetic resonance imaging (MRI)
- Computerized tomography (CT) scan
- Positron emission tomography (PET) scan
Stages of Nasopharyngeal Carcinoma
The TNM staging system is most commonly used for determining the stage of nasopharyngeal carcinoma. The stage of cancer describes how severe the condition is and how best to treat it.
Stage of Cancer
|The tumor is only in the lining of the nasopharynx and has not spread to nearby lymph nodes and other parts of the body.|
|The tumor is in the nasopharynx or has grown into the oropharynx and/or nasal cavity. It has not spread to nearby lymph nodes and other parts of the body.|
|The tumor has either grown into the oropharynx and/or nasal cavity OR has grown into the space around the pharynx and/or nearby muscles. It can also have been spread to the lymph nodes, but not other parts of the body.|
|The tumor has grown into any of the following: oropharynx, nasal cavity, sinuses and/or the bones nearby. It might or might not involve the spread to lymph nodes. The cancer has not spread to distant parts of the body.|
|The tumor has grown into the skull and/or cranial nerves, the lower part of the throat, the main salivary gland, or the eye or its nearby tissues. It might or might not involve the spread to lymph nodes. The cancer has not spread to distant parts of the body.|
|The cancer has spread to other parts of the body, such as the lungs, liver or bones.|
|The cancer comes back after treatment.|
Treatments of Nasopharyngeal Carcinoma
Treatment options for nasopharyngeal carcinoma depend on the stage of cancer. If nasopharyngeal carcinoma is detected early, it can be often cured. The general treatment is radiation therapy, with or without chemotherapy.
- Radiotherapy: Radiation therapy uses high-powered radiation beams to kill or slow down the growth of cancer cells. This method is very effective because most nasopharyngeal carcinoma cancer cells are very sensitive to radiation. Types of radiation therapy include external beam radiation therapy (EBRT) and brachytherapy. Besides, it is usually used in combination with chemotherapy, which is called chemoradiation.
- Chemotherapy: Doctors may prescribe some antineoplastic drugs (e.g. gemcitabine, paclitaxel, carboplatin, cisplatin) often given into the vein or by mouth to kill cancer cells. Chemotherapy may be used in different ways:
(1.) Chemoradiation: Chemotherapy used together with radiotherapy can enhance the effectiveness of radiotherapy.
(2.) Neoadjuvant chemotherapy: Chemotherapy is given before radiotherapy or chemoradiation, but this type of therapy is still controversial.
(3.) Adjuvant chemotherapy: Chemotherapy is given after radiotherapy or chemoradiation, but this type of therapy is still controversial.
- Surgery: It is not a commonly used treatment of nasopharyngeal carcinoma because the area is hard and dangerous to operate on. Therefore, surgery is more often done to remove lymph nodes in the neck instead.
- Other treatments: Targeted drug therapy (e.g. cetuximab) and immunotherapy (immune checkpoints inhibitors, e.g. pembrolizumab, nivolumab) may be used if previous treatments fail.
- Clinical trials: New treatments being tested in clinical trials are also encouraged for patients who have metastatic or recurrent nasopharyngeal carcinoma.
Get Help in Hong Kong
If you are concerned with nasopharyngeal carcinoma, the following resources may be able to help you out:
The most common and noticeable sign of nasopharyngeal cancer is a lump or mass found in the neck. The lumps are neither tender nor painful. Other symptoms include stuffiness, nose bleeding, headache, double vision, hearing loss, facial paralysis, etc.
This article was independently written by Healthy Matters and is not sponsored. It is informative only and not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be relied upon for specific medical advice.