Nasopharyngeal CancerLast Updated: June 11, 2009 This section has been reviewed and approved by the Cancer.Net Editorial Board, 05/09 Overview
Nasopharyngeal cancer (also called nasopharyngeal carcinoma or NPC) is a disease of the nasopharynx, which is the air passageway at the upper part of the pharynx (throat) behind the nose. The pharynx is a hollow tube approximately five inches long that starts behind the nose and ends on top of the larynx (or voice box) and esophagus (the swallowing tube that goes from the throat to the stomach). The nostrils lead through the nasal cavity into the nasopharynx, and an opening on each side of the nasopharynx (called the Eustachian tube opening) leads into the middle ear on each side. Cancer begins when cells in the body become abnormal and multiply without control or order. These cells form a growth of tissue, called a tumor. A tumor can be benign (noncancerous) or malignant (cancerous). There are several types of benign nasopharyngeal tumors, including angiofibromas and hemangiomas that involve the vascular or blood-carrying system, and tumors in the lining of the nasopharynx that include the minor salivary glands. A malignant nasopharyngeal tumor is cancerous and can invade and damage healthy tissues and organs in other parts of the body. The nasopharynx contains several types of tissue, and each contains several types of cells. Different cancers can develop in each kind of cell. The differences are important because they determine the seriousness of the cancer and the type of treatment needed. According to the World Health Organization (WHO), NPC is classified into three subtypes:
NPC is one of five main types of cancer in the head and neck region, a grouping called head and neck cancer. Statistics Nasopharyngeal cancer is uncommon in the United States, with about 2,000 people diagnosed each year. In the last few years, the rate at which Americans have been developing this cancer has been slowly decreasing. NPC is much more common in other parts of the world, such as Asia and North Africa; for instance, in Southeast China it is a fairly common cancer. Cancer statistics should be interpreted with caution. Estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with nasopharyngeal cancer. Source: American Cancer Society Find out more about basic cancer terms used in this section. Medical Illustrations
Risk Factors and Prevention
A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health care choices. Two risk factors greatly increase the risk of NPC: Tobacco use. Use of tobacco (including cigarettes, cigars, pipes, chewing tobacco, and snuff) is the single largest risk factor for head and neck cancer. Smokers with NPC are most likely to have the squamous cell type. Alcohol. Frequent and heavy consumption of alcohol is a risk factor for head and neck cancer. Eighty-five percent (85%) of head and neck cancer is linked to tobacco use. Using alcohol and tobacco together increases this risk even more. However, the influence of tobacco and alcohol in the development of NPC is less than for other head and neck cancers. Recent research suggests that people who have used marijuana may be at higher risk for head and neck cancer. Secondhand smoke may also increase a person’s risk of head and neck cancer. Other factors that can raise a person’s risk of NPC include: Region/ancestry. NPC is most common in people who live in Southeast China and Hong Kong. When people move away from high-risk areas of the world to countries where NPC is less common, subsequent generations of their family have a gradual reduction in their inherited risk of NPC. Epstein-Barr virus (EBV). Exposure to EBV, which is more commonly known as the virus that causes mononucleosis, plays a role in causing nasopharyngeal cancer to develop. Gender. Men are two times more likely than women to develop NPC. Age. NPC most commonly affects people age 30 or older. However, about half of the people with nasopharyngeal cancer in the United States are younger than 55. Diet. Diets high in the consumption of salt-cured fish and meats increase the risk of NPC. Environmental exposure. Extensive exposure to dust and smoke may increase the risk of NPC. Prevention Although some of the risk factors of NPC cannot be controlled, such as age, several can be avoided by making lifestyle changes. Stopping the use of all tobacco products is the most important thing a person can do to reduce the risk of NPC, even for people who have been smoking for many years. Symptoms
People with NPC may experience the following symptoms. Sometimes, people with NPC do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer. If you are concerned about a symptom on this list, please talk with your doctor.
People who notice any of these warning signs should consult a doctor and/or dentist right away. When detected early, cancers of the head and neck have a much better chance of cure. Because many of these symptoms can be caused by other, noncancerous conditions as well, it is important to receive regular health and dental screenings; this is particularly important for people who routinely drink alcohol or currently use tobacco products or have used them in the past. In fact, people who use alcohol and tobacco should receive a general screening examination at least once a year. This is a simple, quick procedure in which the doctor looks in the nose, mouth, and throat for abnormalities and feels for lumps in the neck. If anything unusual is found, then the doctor will recommend a more extensive examination using one or more of the diagnostic procedures mentioned in Diagnosis. Diagnosis
Doctors use many tests to diagnose cancer and determine if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
The following tests may be used to diagnose NPC: Physical examination and blood test. The doctor feels for any lumps on the neck, lips, gums, and cheeks. Also, the doctor will inspect the nose, mouth, throat, and tongue for abnormalities, often using a light and/or mirror for a clearer view. A blood test to check for antibodies against the EBV virus may be done at the same time as the examination. Endoscopy. This test allows the doctor to see inside the body with a thin, lighted, flexible tube called an endoscope. The person may be sedated as the tube is inserted through the mouth or nose to examine the head and neck areas. When an endoscopy is done to look into the nasopharynx, it is called a nasopharyngoscopy. Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed from the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). The type of biopsy performed will depend on the location of the cancer. In a fine needle aspiration biopsy, cells are withdrawn using a thin needle inserted directly into the tumor. The cells are examined under a microscope for signs of cancer (called cytologic examination). The biopsy may be performed using local anesthesia (to numb the area) or general anesthesia. X-ray. An x-ray is a picture of the inside of the body. Sometimes, a barium swallow may be required before having an x-ray. The barium coats the mouth and throat to enhance the image on the x-ray. An x-ray of the skull and chest may be needed to help determine the extent of NPC. Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then combines these images into a detailed, cross-sectional view that shows any abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body, especially images of soft tissue, such as the tonsils and base of the tongue. An MRI is more sensitive than a CT scan in detecting a tumor of the nasopharynx and its possible spread to nearby tissues or lymph nodes. A contrast medium may be injected into a patient’s vein to create a clearer picture. Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. Bone scan. A bone scan uses a radioactive tracer to look at the inside of the bones. The tracer is injected into a patient’s vein. It collects in areas of the bone and is detected by a special camera. Healthy bone appears gray to the camera, and areas of injury, such as those caused by cancer, appear dark. Neurologic tests. This is an examination that involves the doctor testing nerve function, especially tactile sensation of the face and motor function of certain nerves in the head and neck area. Hearing test. The doctor may perform hearing tests if he or she suspects there is fluid in the middle ear. Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body and absorbed by organs or tissues being studied. This substance gives off energy that is detected by a scanner, which produces the images. Learn more about what to expect when having common tests, procedures, and scans. Find out more about common terms used during a diagnosis of cancer. Staging With Illustrations
Staging is a way of describing cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer’s stage, so staging may not be complete until all of the tests are finished. Knowing the stage and histologic grade of cancer helps the doctor to decide what kind of treatment is to be given and can help predict a patient’s prognosis (chance of recovery). There are different stage descriptions for different types of cancer. One tool that doctors use to describe the stage is the TNM system. This system uses three criteria to judge the stage of the cancer: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
Tumor. Using the TNM system, the "T" plus a letter or number (0 to 4) is used to describe the size and location of the tumor in NPC. Some stages are also divided into smaller groups that help describe the tumor in even more detail. Specific tumor stage information is listed below. TX: Indicates the primary tumor cannot be evaluated. T0: No evidence of a tumor is found. Tis: Describes a stage called carcinoma (cancer) in situ. This is a very early cancer where cancer cells are found only in one layer of tissue. T1: Describes a tumor that has not spread beyond the nasopharynx. T2: Describes a tumor that extends into the soft tissue of the middle throat. T3: Describes a tumor that extends into bony structure or into the area behind the nose. T4: Describes a tumor that extends inside the head to the area of the brain or into the lower part of the throat. Node. The “N” in the TNM staging system is for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the head and neck are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes. In people with nasopharynx cancer, doctors examine lymph nodes in a triangle-shaped area formed by these three points: where the neck meets the shoulder, where the collarbone joins the tip of the shoulder, and where the front half of the collarbone meets the base of the neck. NX: Indicates the regional lymph nodes cannot be evaluated. N0: There is no evidence of cancer in the regional lymph nodes. N1: Indicates that cancer has spread to lymph nodes above the triangular area described above. The lymph nodes are on the same side as the primary tumor and the cancer found in the lymph nodes is 6 centimeters (cm) or smaller. N2: Cancer has spread to lymph nodes on both sides of the neck, above the triangular area, but the cancer is 6 cm or smaller. N3: Cancer found in lymph nodes is larger than 6 cm or is found in lymph nodes located in the triangle. N3a: Indicates the cancer found in the lymph nodes is larger than 6 cm. N3b: Indicates the cancer has extended to the triangle region. Distant metastasis. The "M" in the TNM system indicates whether the cancer has spread to other parts of the body. MX: Indicates distant metastasis cannot be evaluated. M0: Indicates the cancer has not spread to other parts of the body. M1: Describes cancer that has spread to other parts of the body. Cancer stage grouping Doctors assign the stage of the cancer by combining the T, N, and M classifications. Stage 0: Indicates a carcinoma in situ (Tis), with no spread to lymph nodes (N0) or distant metastasis (M0).
Histologic grade (G). Doctors also describe a primary tumor by its grade, which is determined by using a microscope to examine tissue from a tumor (called a histologic examination). The doctor compares the tumor tissue with normal tissue. Histologic grade describes how closely the cancer cells resemble normal tissue under a microscope. Normal tissue contains many different types of cells grouped together, which is called differentiated. Tissue from a tumor usually has cells that look more alike each other (called poorly differentiated). Generally, the more differentiated the tissue, the better the prognosis. A tumor's grade is described using the letter "G" and a number. GX: Indicates the grade cannot be evaluated. G1: Indicates the cells look more like normal tissue (well differentiated). G2: The cells are only moderately differentiated. G3: The cells don’t resemble normal tissue (poorly differentiated). Recurrent: Recurrent cancer is cancer that comes back after treatment. Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Sixth Edition (2002) published by Springer-Verlag New York, www.cancerstaging.net. Treatment
The treatment of NPC depends on the size and location of the tumor, whether the cancer has spread, and the patient’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan. This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, visit the Clinical Trials section. Many cancers of the nasopharynx can be cured, especially if found early. Although curing the cancer is the primary goal of treatment, preserving the function of the nearby organs is also very important. When doctors plan treatment, they consider how treatment might affect a person’s quality of life, including how a person feels, looks, talks, eats, and breathes. Head and neck cancer specialists often form a multidisciplinary team to care for each person, and an evaluation should be done before any treatment begins. The team may include medical oncologists, radiation oncologists, surgeons, otolaryngologists (ear, nose, and throat doctors), maxillofacial prosthodontists (specialists who perform restorative surgery in the head and neck areas), dentists, physical therapists, speech pathologists, mental health professionals, nurses, dietitians, and social workers. The main treatment of NPC is called concomitant chemoradiotherapy, which is chemotherapy given in combination with radiation therapy. Surgery for NPC is occasionally used, mainly to remove lymph nodes after chemoradiotherapy or to treat NPC that has recurred (come back after initial treatment). Descriptions of the most common treatment options for nasopharyngeal cancer are listed below. Radiation therapy Radiation therapy is the use of high energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation therapy is called external-beam radiation therapy, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy. External-beam radiation therapy is conducted with a radiation beam aimed at the tumor. It is the most common type used to treat nasopharynx cancer. A new method of external radiation therapy, known as intensity modulated radiation therapy (IMRT), allows for more effective doses of radiation therapy to be delivered while reducing the damage to healthy cells and causing fewer side effects. Also, proton-beam radiation therapy may be used as part of the treatment for some skull-base tumors to further limit the radiation dose to nearby structures, such as the optic (eye) nerves and brainstem; proton therapy may be an option for advanced NPC that is located close to parts of the central nervous system (brain and spinal cord). Stereotactic radiosurgery delivers radiation therapy precisely to the tumor using a machine called a gamma knife. This can be used to treat tumors that have invaded the base of the skull, or tumors that have recurred at the base of the brain or skull. Internal radiation therapy involves tiny pellets or rods containing radioactive materials that are surgically implanted in or near the cancer site. The implant is left in place for several days while the person stays in the hospital. Brachytherapy is most often used to treat cancers that have recurred after initial treatment. It may also be used to treat the original tumor. Before beginning radiation treatment for any head and neck cancer, people should receive a thorough examination from an oncologic dentist (a dentist experienced in treating people with head and neck cancer). Since radiation therapy can cause tooth decay, damaged teeth may need to be removed. Often, tooth decay can be prevented with proper treatment from a dentist before beginning cancer treatment. After radiation therapy for NPC, dental care should continue to help prevent further dental problems. People may receive fluoride treatment to prevent dental caries (cavities). Read more about dental health during cancer treatment. Radiation therapy to the head and neck may cause the following side effects:
Radiation therapy may also cause a condition called hypothyroidism, in which the thyroid gland (located in the neck) slows down and this causes people to feel tired and sluggish. Every patient who receives radiation therapy to the neck area should have his or her thyroid checked regularly. There are numerous studies underway to find ways to reduce or better relieve the side effects of radiation therapy. Chemotherapy Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. Some people may receive chemotherapy in their doctor’s office; others may go to the hospital. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a specific time. Chemotherapy may be given orally (by mouth); given intravenously (in a vein); injected into a muscle, under the skin, or directly into the cancerous tumor. Chemotherapy and radiation therapy are commonly used in combination to treat nasopharyngeal cancer. The use of chemotherapy as an initial treatment or given after surgery and radiation therapy is also being studied. Each drug or combination of drugs can cause specific side effects, and it is important to talk with your doctor about which side effects to expect and if any may be permanent. In general, chemotherapy, in combination with radiation therapy, increases these side effects. Nutritional support may be necessary during treatment due to these side effects. In general, chemotherapy may cause the following side effects:
Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions by using searchable drug databases. Surgery Surgery is sometimes used for NPC when other treatments fail, but it is not a common treatment choice because the area is hard to reach and lies close to cranial nerves and blood vessels. A surgical oncologist is a doctor who specializes in treating cancer using surgery. If the doctor suspects that the cancer has spread to the lymph nodes, a neck dissection (the surgical removal of lymph nodes) may be necessary. In the specific instance of undifferentiated carcinoma of the nasopharynx, neck dissection is occasionally needed. A neck dissection may cause numbness of the ear, weakness when raising the arm above the head, and weakness of the lower lip. The side effects are caused by injury to nerves in the area. Depending on the type of neck dissection, weakness of the lower lip and arm may go away in a few months. However, it is possible that weakness will be permanent if a nerve is removed or damaged as part of a dissection. Facial disfigurement may need to be addressed using reconstructive or plastic surgery. Learn more about cancer surgery. Recurrent NPC Recurrent NPC is treated with radiation therapy, chemotherapy, or in some instances, surgery. Chemotherapy is used for people whose cancer has recurred in distant sites and who were previously treated with radiation therapy only. Chemotherapy may also be used together with radiation therapy (chemoradiotherapy) to improve the effectiveness of the radiation therapy. In addition, a clinical trial of biologic therapy may be an option (see Current Research). Find out more about common terms used during cancer treatment. Clinical Trials Resources
Doctors and scientists are always looking for better ways to treat patients with NPC. A clinical trial is a way to test a new treatment to prove that it is safe, effective, and possibly better than a standard treatment. The clinical trial may be evaluating a new drug, a new combination of existing treatments, a new approach to radiation therapy or surgery, or a new method of treatment or prevention. Patients who participate in clinical trials are among the first to receive new treatments, such as new chemotherapy drugs, before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment. Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that finding new drugs and other therapies is the only way to make progress in treating NPC. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with NPC. Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill”. The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials. To join a clinical trial, patients must participate in a process known as informed consent. During informed consent, the doctor should list all of the patient’s options, so the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different than the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find cancer clinical trials. For specific topics being studied for nasopharyngeal cancer, learn more in the Current Research section. Side Effects
Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects do occur. Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health-care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and the person’s overall health. Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health-care team if they do happen. Also, be sure to communicate with the doctor about side effects you experience during and after treatment. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them. In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. Learn more about the importance of addressing such needs, including concerns about managing the cost of your cancer care. Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your doctor. After Treatment
After treatment for NPC ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your recovery for the coming months and years. People treated for NPC should receive regular follow-up medical and dental examinations to check for signs of recurrent cancer or a secondary cancer (a different type of cancer). During follow-up visits, doctors may check thyroid functioning, vision, and hearing to detect any cranial nerve damage from treatment. They may also take an MRI or CT scan six to eight weeks after treatment, called a baseline study. If the cancer comes back, the baseline study will help them track when the changes began. Most recurrences of NPC happen in the first two to three years after treatment, so follow-up visits will be more frequent in the years immediately following treatment. People who have had NPC have a higher risk of developing a secondary cancer. Researchers are evaluating the benefits of using chemotherapy as a way to prevent second cancers (called chemoprevention). Follow-up visits will also help manage any late or long-term side effects from cancer treatment, such as buildup of earwax. Periodic ear examinations are necessary to remove buildup of dried earwax. Prevention of dental cavities is also important. Fluoride application is recommended whenever the oral cavity and the salivary glands receive radiation treatment. Rehabilitation is a major part of follow-up care after head and neck cancer treatment. People may receive physical therapy and speech therapy to regain skills, such as speech and swallowing. Supportive care to manage symptoms and maintain nutrition during and after treatment may be recommended. Some people may need to learn new ways to eat or to eat foods prepared differently. People may look different, feel tired, and be unable to talk or eat the way they used to. Many people experience depression. The health-care team can help people adjust and connect them with both physical and emotional support services. People recovering from NPC are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate physical activity can help rebuild your strength and energy level. Your doctor can help you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level. Learn more about healthy living after cancer. Find out more about common terms used after cancer treatment is complete. Current Research
Research for NPC is ongoing. The following advance may still be under investigation in clinical trials and may not be approved or available at this current time. Always discuss all diagnostic and treatment options with your doctor. Biologic therapy. Biologic therapy (also called immunotherapy) is designed to boost the body’s natural defenses to fight cancer. It uses materials either made by the body or in a laboratory to bolster, target, or restore immune system function. Treatment based on the specific biologic characteristics of a tumor is being used with increasing frequency and being tested in clinical trials. People should talk with their doctors about the availability of these studies. Questions to Ask the Doctor
Regular communication with your doctor is important in making informed decisions about your health care. Consider asking the following questions of your doctor:
Patient Information Resources
In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease. View organizations that offer information on this specific type of cancer. |
