Diagnosis of pharyngeal cancer

Diagnosis is the process of finding out the cause of a health problem. Diagnosing cancer often means first ruling out other health conditions that share similar symptoms with cancer. It can be a very worrying time for you and your loved ones. Sometimes this process is quick. Sometimes it can feel long and frustrating. But it’s important for doctors to get all the information they need before making a diagnosis of cancer.

Diagnosing pharyngeal cancer usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and do a physical exam. Based on this information, your doctor may refer you to a specialist or order tests to check for pharyngeal cancer or other health problems.

The following tests are usually used to rule out or diagnose pharyngeal cancer. Many of the tests used to diagnose cancer are also used to find out its stage, or how far the cancer has spread. Your doctor may also order other tests to check your general health and to help plan your treatment.

Your health history is a record of your symptoms, risks and all the medical events and problems you have had in the past. Your doctor will ask questions about your history of:

• symptoms that suggest pharyngeal cancer
• smoking tobacco
• drinking alcohol
• human papillomavirus (HPV) infection
• Epstein-Barr virus infection

Your doctor may also ask about a family history of:

• head and neck cancers
• other cancers

A physical exam allows your doctor to look for any signs of pharyngeal cancer. During a physical exam, your doctor may:

• feel your neck area for lumps or swelling
• check the inside of your mouth, including your cheeks and lips
• feel the floor of your mouth and the base of your tongue
• examine the roof of your mouth, the back of your throat and your nasal cavity
• check your ears and test your hearing
• examine your jaw and mouth to see if they move normally
• do an eye exam and test your vision

Find out more about physical exams.

An upper GI series is an imaging test in which doctors look at a series of x-rays of your upper digestive system, including the esophagus, stomach and upper small intestine (duodenum). It’s also called a barium swallow. You will swallow a thick, chalky liquid (barium) that coats the inside of these organs and makes their outline show up clearly on an x-ray image. A series of x-rays are taken as the barium moves from your throat to your upper GI tract. An upper GI series can show any abnormalities in the throat when you swallow, so it’s often the first test done if you have trouble swallowing.

Find out more about an upper gastrointestinal (GI) series.

An endoscopy is a test doctors use to diagnose pharyngeal cancer and find out what stage the cancer is at. It allows a doctor to look inside the body using a flexible tube with a light and lens on the end. This tool is called an endoscope. Instruments can be inserted through a channel in the endoscope to remove small pieces of tissue for testing.

Different types of endoscopies may be used by the doctor to look inside your throat, collect tissue samples and find out how far the cancer has spread (metastasized).

A nasopharyngoscopy lets the doctor look at the upper part of your throat (the nasopharynx), the middle part of your throat (the oropharynx) and your voice box (larynx). It’s usually done by an ear, nose and throat (ENT) specialist in the doctorʼs office. A topical anesthetic may be applied to numb the back of your throat just before the procedure. During the procedure, the doctor inserts a flexible endoscope through the nose and down to the throat.

A panendoscopy looks at all the structures in the throat. It combines 3 kinds of endoscopies.

• A laryngoscopy uses an endoscope to examine the larynx.
• An esophagoscopy uses an endoscope to examine the esophagus.
• A bronchoscopy uses an endoscope to examine the airways (bronchi) in the lungs.

A panendoscopy is usually done in an operating room under a general anesthetic (you will be unconscious). After the procedure, you won’t be allowed to eat or drink for about an hour. You will also be told to rest your voice by not speaking. Your healthcare team may give you pain-relieving drugs if you have a sore throat.

Your doctor may do a panendoscopy to thoroughly check the mouth (oral cavity), nasopharynx, oropharynx, larynx, esophagus, windpipe (trachea) and bronchi.

Endoscopy is not used for cancers in the hypopharynx, which is the lower part of the throat. The hypopharynx is a very small space and is difficult to examine with an endoscope.

Find out more about endoscopies.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from the pathologist will show whether or not cancer cells are found in the sample. There are different kinds of biopsies that may be done.

An endoscopic biopsy is done during an endoscopy. The doctor collects tissue samples from any abnormal areas in the pharynx.

A punch biopsy is used to take a sample from the mucous membrane lining the pharynx. The doctor uses a special round cutting tool called a punch. A sample of an abnormal area is removed along with a small amount of normal tissue around it.

An incisional biopsy removes only a small sample of the tumour or abnormal tissue. The doctor makes a small cut (incision) through the skin of the throat or in the mucous membrane of the pharynx to collect a sample from a lump.

An excisional biopsy is a type of biopsy most often done to remove a lymph node in the neck. The doctor makes a cut in the neck and removes the entire lymph node or nodes, and any abnormal area along with a small amount of normal tissue around it.

A fine needle aspiration (FNA) uses a very thin needle and syringe to remove a small amount of fluid or cells from the abnormal area. FNA may be used to collect cell or tissue samples from lumps and lymph nodes in the neck. An ultrasound or a CT scan may be used to guide the needle into the abnormal area if the doctor can’t see or feel it.

Find out more about biopsies.

An x-ray uses small amounts of radiation to make an image of parts of the body on film. Itʼs used to look for a tumour in the pharynx. You may have a chest x-ray to see if cancer has spread to the lungs or lymph nodes in the chest.

Find out more about x-rays.

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. Computer software turns the images into detailed pictures.

A CT scan is used to:

• find out the size and location of a tumour
• find out how far the tumour has grown into surrounding tissues
• see if the cancer has spread to structures or lymph nodes in the neck
• help decide whether or not the tumour can be removed with surgery

Find out more about CT scans.

An ultrasound uses high-frequency sound waves to make images of parts of the body. It is used to:

• check if cancer has spread to lymph nodes in the neck (cervical lymph nodes)
• check if the tumour has grown into major blood vessels in the neck, such as the carotid arteries
• guide a needle during a fine needle aspiration

Find out more about ultrasounds.

Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. Computer software turns the images into detailed 3D pictures.

An MRI is used to:

• examine soft tissues in the head and neck, such as the base of the tongue
• find out the size of a tumour

Find out more about MRIs.

A positron emission (PET) scan uses a small amount of radioactive materials to look for changes in how active your body tissues are. Computer software analyzes the radioactive patterns and makes detailed, 3D colour images of the area being scanned.

A PET scan is used to see if the cancer has spread (metastasized) to the lymph nodes in the neck or other distant sites.

Find out more about PET scans.

A PET-CT scan combines a CT scan and a PET scan. It can give the healthcare team a more complete image of the tumour, including its location and size and if it has spread.

Blood tests are not used to diagnose pharyngeal cancer. But they are routinely done to provide a baseline before any planned treatment. They can provide helpful information about your general health, how other organs are functioning, other medical conditions and the possible risks of treatment.

Blood tests that may be used are:

• a complete blood count (CBC), which measures the number and quality of white blood cells, red blood cells and platelets
• blood chemistry tests, which measure certain chemicals in the blood and show how well certain organs, such as the liver and kidneys, are working

A DPD blood test is done before you start chemotherapy for pharyngeal cancer. It’s needed if you are having the drug fluorouracil or capecitabine as part of your treatment. DPD is an enzyme, controlled by the DPYD gene, that helps the liver break down these drugs so that they can be removed from the body. But changes to the DPYD gene can cause lower levels of the enzyme. A DPD deficiency can cause the chemotherapy drugs to build up in the body. If this happens, the side effects can be severe and life-threatening. If you have lower levels of DPD, your healthcare team will avoid giving you fluorouracil and capecitabine as part of your treatment.

Find out more about a complete blood count and blood chemistry tests.

Cells and tissues are analyzed in the lab to look for cancer. A report from a pathologist will show whether or not cancer cells are found in the sample and which type of cancer has been found.

Special lab techniques are used to prepare the samples so that very small details in the cells and tissues can be seen under a microscope.

Once pharyngeal cancer has been diagnosed, other tests are done on the pharyngeal cancer cells to find out more information about the cancer. Biomarker testing looks for certain changes to the cancer cells. The presence of certain biomarkers helps your healthcare team determine which treatments will work best for your type of pharyngeal cancer.

PD-L1 is a protein that some cancer cells, including pharyngeal cancer cells, may have in large amounts. When PD-L1 attaches to another protein called PD-1 in the immune system’s T cells, it keeps the T cells from killing cancer cells that contain PD-L1. If testing shows that the tumour has high amounts of PD-L1, certain drugs that are effective against PD-L1 can be part of your treatment plan.

If you’ve been diagnosed with pharyngeal cancer in the middle part of the pharynx (oropharyngeal cancer) or the upper part of the pharynx (nasopharyngeal cancer), your healthcare team may also do tests to look for certain viruses.

Human papillomavirus (HPV) increases the risk of oropharyngeal cancer. But it also improves the outlook for the disease. HPV-related oropharyngeal cancers respond better to treatment than HPV-negative tumours. An HPV test is done on the tissues that were removed during a biopsy.

An HPV test is done for oropharyngeal cancer, but it isn’t done for other types of pharyngeal cancers.

Epstein-Barr virus (EBV) increases the risk for nasopharyngeal cancer. Your healthcare team may order a blood test to look for the virus if you have been diagnosed with this kind of pharyngeal cancer. Tests for EBV are also done on tissues that were removed during a biopsy.

EBV-positive tumours may have a different prognosis and react differently to treatment than EBV-negative tumours. EBV testing is used only for nasopharyngeal cancer.

To make the decisions that are right for you, ask your healthcare team questions about a diagnosis.