Nasopharyngeal cancer - Treatments, Symptoms, Causes
What is Nasopharyngeal - Upper Throat Cancer? What are its causes and risk factors?
The pharynx, or throat, is located at the back of the mouth and nasal cavity. It is a muscular organ, approximately 12 cm in length and lined with mucous membrane, which starts at the back of the nose and ends above the trachea and esophagus. The pharynx is an organ responsible for the passage of food to the stomach and breathing. In other words, it acts as a conduit for air from the mouth to the lungs and food from the mouth to the esophagus, with the entrance to the trachea closing as food passes through.
Nasopharyngeal (upper throat) cancer begins in this region. It is a type of head and neck cancer often seen in Asian countries. Although this cancer is more commonly observed in older individuals, it can also occur in younger people.
What are the causes and risk factors of nasopharyngeal (upper throat) cancer?
Anything that changes the chances of developing a disease is a risk factor. Therefore, by paying attention to our lifestyle, habits, and all environmental factors we are exposed to, we can reduce the risk factors that affect cancer. Some risk factors, such as smoking and alcohol use, are habits we acquire throughout our lives and can be changed. On the other hand, some risk factors, such as age and family history, cannot be changed. However, having a risk does not necessarily mean that you will develop cancer, or you may get cancer even without any risk factors.
Therefore, knowing the influential risk factors for nasopharyngeal cancer is essential. In this way, you can reduce the risk with small changes you make in your life. For example, if you have some nasopharyngeal cancer risk factors, do not miss routine check-ups at frequent intervals. Thus, you can have an early diagnosis and effective treatment for cancer.
What are the symptoms of Nasopharyngeal - Upper Throat Cancer?
Nasopharyngeal cancer usually does not show any symptoms. A person often goes to the doctor with complaints of swelling in the neck. Some common symptoms associated with nasopharyngeal cancer include hearing loss, nasal congestion, ringing in the ears, nosebleeds, fluid accumulation in the ear, vision problems (double vision, strabismus, etc.), voice changes, and speech disorders. However, it is incorrect to associate these symptoms with nasopharyngeal cancer directly. Other non-serious health problems can also lead to such symptoms. In this case, you should immediately consult an expert doctor without wasting time. This way, a quick solution for the health problem detected early can be found.
Tumors that occur in the nasal cavity area.
Several different types of tumors are known to develop in the nasopharynx. Some of them are benign tumors, while others can be malignant. Let's examine these types of cancer together.
Nasopharyngeal carcinoma.
Nasopharyngeal carcinoma, which starts in epithelial cells (cells covering the body's internal and external surfaces), is the most common cancer in the nasopharynx. There are three different types of nasopharyngeal carcinoma: • Keratinizing squamous cell carcinoma, • Non-keratinizing differentiated carcinoma • Undifferentiated (undifferentiated) carcinoma. Although these cancer types appear additional, they develop from the same cell. This cell type is the epithelial cells that cover the surface of the nasopharynx. Therefore, the treatment methods applied for all nasopharyngeal cancer are generally the same.
Benign Nasopharyngeal Tumors
Benign tumors in the nasopharynx are more common in young people and children and are rare. Therefore, it can be said that these types of tumors do not spread to the body and generally do not pose a life-threatening risk. However, when necessary, the treatment applied dithate treatment of nasopharyngeal cancer. Is early diagnosis and screening possible for nasopharyngeal cancer? How is it diagnosed?
Medical history and physical examination
During the physical examination, signs related to nasopharyngeal cancer are investigated by looking at the nose, mouth, throat, facial muscles, and lymph nodes in the head and neck region, and the person's medical history related to this disease is examined, including a family history of nasopharyngeal cancer. If the tumor begins to develop below the surface of the nasopharynx (submucosal layer), it isn’t easy to detect it through physical examination. Therefore, imaging and laboratory tests are used for a more detailed analysis of suspicious cases.
Imaging tests
X-rays, magnetic fields, sound waves, or radioactive material are used in imaging tests. Imaging tests are applied to determine whether the suspicious area is cancerous, to detect the spread of cancer, to evaluate the effectiveness of treatment, and to examine the tendency of cancer to recur. Chest x-ray, computed tomography (CT), magnetic resonance imaging (MRI), and PET tomography are commonly used imaging tests for diagnosing nasopharyngeal cancer.
Blood tests
Blood tests, rarely used in diagnosing nasopharyngeal cancer, detect cancer spread to other body parts.
Epstein-Barr virus (EBV) DNA level
Most patients with nasopharyngeal cancer have signs of infection associated with the Epstein-Barr virus (EBV) in their blood. Therefore, measuring the DNA level of Epstein-Barr virus (EBV), which plays an active role in this type of cancer, is vital in determining the course of the disease.
Biopsy
The symptoms and physical examination findings may indicate that the person has nasopharyngeal cancer. However, the actual diagnosis is made by examining the cell samples taken from the suspicious area in a laboratory environment. This procedure is called a biopsy. Different biopsy methods can be used depending on the suspicious site.
Endoscopic biopsy: During the examination of the nasopharynx, a biopsy sample is taken from the suspected area with the help of a fiber optic microscope using tiny instruments. The type of cancer is determined by examining it. This is a straightforward outpatient procedure.
Fine-needle aspiration biopsy: Fine-needle aspiration biopsy may be used if there is a suspicious swelling in or near the neck. In this procedure, a thin needle is inserted into the suspicious bulge, and a sample of fluid containing cells and small tissue particles is taken. Local anesthesia may be required from time to time in the area where the needle was inserted. The fluid sample is examined in the environment, and possible cancer is detected.
A fine needle biopsy can detect cancer that starts in the lymph nodes (lymphoma), the spread of cancer to other regions, or the enlargement of the lymph nodes in the neck region due to infection.
Chemotherapy and targeted therapies in nasopharyngeal cancer
Chemotherapy is a drug therapy to kill cancer cells. Chemotherapy treatment includes cancer drugs used orally or injected through a vein. These drugs effectively treat all tumor that has spread throughout the body, beyond the head and neck region of cancer, by circulating the whole body through the bloodstream.
Cisplatin is the most commonly used chemotherapy drug in the treatment of nasopharyngeal cancer. Although it can usually be used alone as part of chemoradiotherapy efficacy of therapy can be increased by concurrent radiotherapy with 5-fluorouracil (5-FU). In addition, cisplatin and 5-FU combined therapy can be used after radiotherapy to prevent cancer recurrence.
Carboplatin (Paraplatin®), doxorubicin (Adriamycin®), epirubicin (Ellense®), paclitaxel (Taksol®), docetaxel (Taksotere®), gemcitabine (Gemzar®), bleomycin and methotrexate, chemotherapy that may be beneficial in the treatment of advanced stage nasopharyngeal cancer areas to increase therapy’s efficacy of medicine by using two or more of these drugs in combination in patients whose health conditions allow it.
Targeted therapy – smart drugs
As more is learned about the cancer-causing changes within the cell, new drugs targeting these changes continue to be developed. These targeted drugs work differently from standard chemotherapy drugs. Therefore, in cases where chemotherapy drugs are ineffective in treatment, targeted drugs may be preferred.
Cetuximab (Erbitux®)
Cetuximab is a monoclonal antibody (synthetic immune system protein) that targets the epidermal growth factor receptor (EGFR). EGFR is a protein found on the surface of cells and typically receives signals for cell growth and division. The cell with cancer of the nasopharynx sometimes has enough EGFR to accelerate growth. Cetuximab slows or stops the rapid growth of EGFR. This drug is often used in combination with chemotherapy and radiotherapy if cancer continues to develop or recurs after chemotherapy treatment.
The primary role of cetuximab in the treatment of nasopharyngeal cancer remains the subject of research.
How is nasopharyngeal cancer treated?
The proximity of upper pharyngeal cancer to the brain, a vital organ, and the rapid spread of cancer through the blood and lymph system limit the application of surgical treatment methods. For this reason, treatment methods that prioritize chemotherapy and radiotherapy are generally preferred. In addition, targeted therapies are among the techniques used according to the course of the disease.
Radiotherapy – radiation therapy in nasopharyngeal cancer
Radiotherapy aims to kill cancer cells or slow their growth using high-energy X-rays or particles. This treatment method is applied as part of the primary treatment in nasopharyngeal cancers.
Chemotherapy and radiotherapy can be applied simultaneously to increase the effectiveness of treatment in nasopharyngeal cancer. This treatment method, chemoradiotherapy, may be more effective than radiotherapy treatment alone.
Brachytherapy (internal radiotherapy)
Brachytherapy is applied by placing a high-power radioactive beam source on cancer cells. Thanks to this light source placed inside, it is possible to give high doses of radiation to the cancerous area. This application minimizes side effects as it causes less damage to healthy tissues.
Nasopharyngeal cancer surgery
Nasopharyngeal cancer is a type in which surgical intervention is complex because it is close to vital organs such as the brain and spreads rapidly. With the new endoscopic surgical techniques, some nasopharyngeal tumors can be removed using a flexible fiber optic microscope and long, thin surgical instruments. However, this practice is only an option for many patients to benefit from effective treatments such as radiotherapy.
For example, only lymph nodes close to the primary tumor site and where the cancer is likely to spread can be removed (partial neck dissection). Or, lymph nodes and some muscle and nerve tissue are drawn on one side of the neck, between the jawbone and collarbone. However, the primary nerve extending to the shoulder muscle is usually not removed (modified radical neck dissection). Another option is the removal of almost all lymph nodes along with muscles, nerves, and vessels on one side of the neck (radical neck dissection).
Immunotherapy in nasopharyngeal cancer
On August 5, 2016, the US Food and Drug Administration (FDA) approved using Pembrolizumab (Keytruda), an immunotherapy drug for treating head and neck cancers. The most common cell type of head and neck cancer (HNC) is squamous cell carcinoma. The most common location of these cancers is in anatomical regions in contact with air (such as the mouth, pharynx - nasal - pharynx, and larynx). Here, Pembrolizumab is approved for relapsed or disseminated (metastatic = stage 4) squamous cell HNC whose disease worsens under or after platinum-based chemotherapy.
Heat – hyperthermia treatment in nasopharyngeal cancer
When hyperthermia is applied with radiotherapy for treating head and neck cancers, it increases the complete response rate, which is one of the most important indicators of treatment success, by approximately 25%. Furthermore, it can do this without causing additional side effects. Therefore, integrating hyperthermia into treating head and neck cancers is an application with a high level of evidence (level 1 evidence).
Hyperthermia, also known as heat therapy or thermotherapy, is a complementary cancer treatment method that is applied by exposing body tissue to high heat (39 – 44 °C).
Studies have shown that high heat damages or kill cancer cells with minor wear to normal tissues. Conversely, Hyperthermia can shrink the tumor by killing cancer cells and damaging the proteins and structure in the cells.
Gene therapy
It has been discovered that specific gene mutations in nasopharyngeal cells cause cancer. Using viruses, it is promising to repair p53, a tumor suppressor gene that has a crucial role in many cancers. However, this approach is still being worked on.