Tests for Nasopharyngeal Cancer

Nasopharyngeal cancer (NPC) is most often diagnosed when a person goes to a doctor because of symptoms such as a lump in the neck or stuffy nose, but no other signs of a cold.

Medical history and physical exam

If you have signs or symptoms that suggest you might have NPC, the doctor will want to get your complete medical history. You will be asked about the changes you've noticed, possible risk factors, and your family history.

The doctor will do a physical examination to look for signs of NPC or other health problems. A more complete exam of your nasopharynx will be done. During the exam, the doctor will pay close attention to your head and neck, including your nose, mouth, and throat; your facial muscles; and the lymph nodes in your neck.

Exams by a specialist

The nasopharynx is deep inside the head and isn't easily seen, so special techniques are needed to examine this area. You will probably be referred to an ear, nose and throat (ENT) doctor (also called an otolaryngologist) because they have the specialized training and equipment to do a complete exam of this part of the body. The main types of exams used to look inside the nasopharynx for abnormal growths, bleeding, or other signs of disease are usually done in the doctor's office.

• Indirect nasopharyngoscopy: The doctor uses special small mirrors and bright lights, just like during an indirect laryngoscopy, to look at the nasopharynx and nearby areas.
• Direct nasopharyngoscopy: A fiberoptic scope, similar to the one used during a direct laryngoscopy, is used to look directly at the lining of the nasopharynx. This is the method most often used to carefully examine the nasopharynx.

If a tumor starts under the lining of the nasopharynx (in the tissue called the submucosa), the doctor may not be able to see it. Because of this, imaging tests like CT or MRI scans (see below), may be needed.

Depending on your signs and symptoms, you might also be referred for:

• A baseline hearing test by an audiologist
• A complete exam of your eyes and vision by an ophthalmologist (eye doctor)
• A full dental exam by a dentist
• An evaluation of your speech and swallowing ability by a speech therapist.

Types of biopsies

In a biopsy, the doctor removes a small piece of tissue or a sample of cells, so it can be tested in the lab for cancer cells. A biopsy is the only way to know for sure that NPC is present. Several types of biopsies may be used, depending on circumstances.

See Testing Biopsy and Cytology Specimens for Cancer to learn more.

Endoscopic biopsy

If a growth is seen in the nasopharynx, the doctor may take out a tiny piece of it with small instruments and the aid of a fiber-optic scope. Often, biopsies of the nasopharynx are done in the operating room while you are under general anesthesia (a deep sleep) as an outpatient procedure. The tissue sample is then sent to a lab, where a pathologist (a doctor who specializes in diagnosing and classifying diseases in the lab) looks at it closely to see if there are cancer cells.

NPC cannot always be seen during an exam. If a person has symptoms suggesting NPC but nothing looks abnormal on exam, the doctor may biopsy normal-looking tissue, which may be found to contain cancer cells when looked at and tested by a pathologist.

Fine needle aspiration (FNA) biopsy

An FNA biopsy may be used if you have a suspicious lump in or near your neck. To do this, the doctor puts a thin, hollow needle into the lump to remove fluid containing cells or tiny bits of tissue. The cells are then looked at in the lab to see if they are cancer cells.

An FNA biopsy can show if an enlarged lymph node in the neck is caused by the spread of cancer from somewhere else (such as the nasopharynx) or a cancer that starts in lymph nodes (lymphoma). Lymphomas can start in the nasopharynx but this only happens about 5% of the time.  If the cancer started somewhere else, the FNA biopsy alone might not be able to tell where it started. But if a patient already known to have NPC has enlarged neck lymph nodes, FNA can help find out if the spread of NPC caused the swelling.

Lab tests of biopsy samples

Biopsy samples (from endoscopy or surgery) are sent to the lab where they are looked at closely. If cancer is found, other lab tests may also be done on the biopsy samples to help better classify the cancer.

Tests for certain proteins on tumor cells: If the cancer has spread (metastasized) or come back, doctors will probably look for certain proteins on the cancer cells. For example, cancer cells might be tested for the PD-L1 protein which, if found, might predict if the cancer is more likely to respond to treatment with certain immunotherapy drugs.

Imaging tests

Imaging tests use x-rays, magnetic fields, sound waves, or radioactive substances to make pictures of the inside of your body. Imaging tests are not used to diagnose nasopharyngeal cancers, but they're done for a number of reasons after a cancer diagnosis, such as:

• To look at suspicious areas that might be cancer
• To learn how far cancer may have spread
• To help determine if treatment is working
• To look for signs that the cancer has come back after treatment

Chest x-ray

If you've been diagnosed with NPC, a plain x-ray of your chest might be done to see if the cancer has spread to your lungs, but more often a CT scan of the lungs is done since it tends to give more detailed pictures.

Computed tomography (CT) scan

The CT scan is an x-ray test that makes detailed cross-sectional images of your body.

A CT scan of the head and neck can provide information about the size, shape, and position of a tumor, see if it's growing into nearby tissues, and can help find enlarged lymph nodes that might contain cancer. A CT scans can also look for cancer that may have grown into the bones at the base of the skull. This is a common place for nasopharyngeal cancer to grow. CT scans can also be used to look for tumors in other parts of the body.

Magnetic resonance imaging (MRI) scan

Like CT scans, MRI scans make detailed images of soft tissues in the body. But MRI scans use radio waves and strong magnets instead of x-rays. A contrast material called gadolinium is often injected into a vein before the scan to get clear pictures.

An MRI scan is often done to try to find out if the cancer has grown into structures near the nasopharynx including the nerves. MRIs are a little better than CT scans at showing the soft tissues in the nose and throat.

Positron emission tomography (PET) scan

PET scans use a slightly radioactive form of sugar that's injected into the blood collects mainly in cancer cells.

A PET scan may be used to look for possible areas of cancer spread, especially if the main cancer is advanced. This test can also be used to help tell if a suspicious area seen on another imaging test is cancer or not.

PET/CT scan: Some machines are able to do both a PET and CT scan at the same time. This lets the doctor compare areas of higher radioactivity on the PET scan with the more detailed pictures on the CT scan.

Bone scan

For a bone scan, a small amount of low-level radioactive material is injected into the blood and collects mainly in abnormal areas of bone. A bone scan can help show if a cancer has spread to the bones. But this test isn’t needed very often because PET scans are good at showing if cancer has spread to the bones.

Other pre-treatment tests

Other tests may be done as part of a workup in people diagnosed with nasopharyngeal cancer. These tests are not used to diagnose the cancer, but they may be done to see if a person is healthy enough for certain treatments, like radiation or chemotherapy.

Quit smoking: It is very important to quit smoking before starting any treatment for nasopharyngeal cancer. If you used to smoke cigarettes before being diagnosed, it is important to not start during treatment. Smoking during treatment can cause a poor response to radiation treatment, poor wound healing, poor tolerance to chemotherapy, and a higher chance of dying. 

Epstein-Barr virus (EBV) DNA levels: Tests to measure the blood level of EBV DNA may be done before and after treatment. It might help show how well treatment is working and might also help in choosing certain chemo drugs for treatment. The level of EBV DNA in the blood before treatment can also help determine your prognosis (outlook).

Routine blood counts and blood chemistry tests: Routine blood tests can help determine a patient’s overall health. These tests can help diagnose nutrition problems, anemia (low red blood counts), liver disease, and kidney disease. And they may suggest the possibility of spread of the cancer to the liver or bone, which may lead to more testing. These tests can also help determine how well your body might tolerate treatment like chemo.

Pre-surgery (before surgery): Even though surgery is not the main treatment for NPC, if surgery is planned, you might also get an electrocardiogram (EKG) to make sure your heart is working well. Some people having surgery also may need tests of their lung function known as pulmonary function tests (PFTs).

Dental exam: Your cancer care team will also have you see your dentist before any radiation is given since it can damage the saliva (spit) glands and cause dry mouth. This can increase the chance of cavities, infection, and breakdown of the jawbone.

Hearing test: The most commonly used chemotherapy drug used in treating nasopharyngeal cancer, cisplatin, can affect your hearing. Side effects can range from ringing in the ears to hearing loss. Your care team will most likely have your hearing checked (with an audiogram) before starting treatment. If your hearing is already poor, your doctor might recommend a different chemotherapy drug. 

Nutrition and speech tests: Often, you will have a nutritionist who will evaluate your nutrition status before, during, and after your treatment to try and keep your body weight and protein stores as normal as possible. You might also visit a speech therapist who will test your ability to swallow and speak. They might give you exercises to do during treatment to help strengthen the muscles in the head and neck area so you can eat and talk normally after finishing all of your cancer treatment.