Skip to main content

What is Oropharyngeal Cancer?

The Oropharynx

Oropharyngeal cancer develops in oropharynx, the part of the throat just behind the mouth and begins where the oral cavity ends. It is also called throat cancer. It includes the base of the tongue (back third of the tongue), the soft palate (the back part of the roof of the mouth), the tonsils, and the side and back wall of the throat.

The oropharynx helps you to breathe, talk, eat, chew, and swallow. Minor salivary glands located throughout the oropharynx make saliva that keeps your mouth moist and helps you digest food. And, It is composed of several types of body tissues, which are made up of several types of cells.

Squamous Cell Carcinomas

More than 90% of oropharynx cancers are squamous cell carcinomas, also called squamous cell cancers. Squamous cells are flat, scale-like cells that normally form the lining of the mouth and throat. Squamous cell cancer begins as a collection of abnormal squamous cells.

The earliest form of squamous cell cancer is called carcinoma in situ, meaning that the cancer cells are present only in the outer layer of cells called the epithelium. This is different from invasive squamous cell carcinoma, where the cancer cells have grown into deeper layers of the oropharynx.

Risk Factors

Following are common risk factors for the disease:

  • Smoking and chewing tobacco
  • Heavy alcohol use
  • A diet low in fruits and vegetables
  • Drinking maté, a stimulant drink common in South America
  • Chewing betel quid, a stimulant commonly used in parts of Asia
  • Being infected with Human Papillomavirus (HPV) 

Signs and Symptoms

These and other symptoms may be caused by oropharyngeal cancer. Other conditions may cause the same symptoms.

A doctor should be consulted if any of the following problems occur:

  • A sore throat that does not go away
  • A dull pain behind the breastbone
  • Cough
  • Trouble swallowing
  • Weight loss for an unknown reason
  • Ear pain
  • A lump in the back of the mouth, throat, or neck
  • A change in voice

Learn More About Eating Well with Head & Neck Cancer


If a patient has symptoms that could be oropharyngeal cancer, the doctor will test for fever and high blood pressure and check general signs of health.

The patient will likely have one or more of the following tests:

  • A Physical Exam - An exam of the body to check general signs of health, including checking for signs of disease, such as swollen lymph nodes in the neck or anything else that seems unusual. The doctor does a complete exam of the mouth and neck and looks down the throat with a small, long-handled mirror to check for abnormal areas. A history of the patient’s health habits and past illnesses and treatments will also be taken. 
  • CT Scan - A procedure that makes a series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show up more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography. 
  • MRI - A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body. This procedure is also called nuclear magnetic resonance imaging (NMRI). 
  • X-Rays - An x-ray of the organs and bones. An x-ray is a type of energy beam that can go through the body and onto film, making pictures of areas inside the body. 
  • PET Scan - A procedure to find malignant tumor cells in the body. A small amount of radionuclide glucose (sugar) is injected into a vein. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than normal cells do. 
  • Endoscopy - A procedure to look at organs and tissues inside the body to check for abnormal areas. An endoscope is inserted through the patient’s nose or mouth to look at areas in the throat that cannot be seen during a physical exam of the throat. 
  • Biopsy - The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer.


If oropharyngeal cancer is diagnosed, the doctor needs to know the stage, or extent, of the disease to plan the best treatment. Staging is a careful attempt to find out whether the cancer has spread, and if so, to what parts of the body.

Knowing the stage assists the doctor in determining a prognosis. It also better helps you understand the care and treatment that will be required.

These are the main features of each stage of the disease:

Stage 0 (Carcinoma in Situ)

In stage 0, abnormal cells are found in the lining of the oropharynx. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

In stage I cancer has formed and is two centimeters or smaller. It is also only found in the oropharynx.

Stage II

In Stage II, the cancer is larger than two centimeters but not larger than four centimeters and is found in the oropharynx only.

Stage III

In stage III, cancer is either four centimeters or smaller; spread to one lymph node on the same side of the neck as the tumor and the lymph node is three centimeters or smaller; or it is larger than four centimeters or has spread to the epiglottis (the flap that covers the trachea during swallowing). Cancer may have spread to one lymph node on the same side of the neck as the tumor and the lymph node is three centimeters or smaller.

Stage IV

Stage IV is divided into stage IVA, IVB and IVC as follows:

In stage IVA - Cancer has spread to the larynx, front part of the roof of the mouth, lower jaw, or muscles that move the tongue or are used for chewing. Cancer may have spread to one lymph node on the same side of the neck as the tumor and the lymph node is three centimeters or smaller. OR, cancer has spread to one lymph node on the same side of the neck as the tumor - the lymph node is larger than three centimeters but not larger than six centimeters - or to more than one lymph node anywhere in the neck. One of the following must also be true:

A tumor in the oropharynx is any size and may have spread to the epiglottis.

A tumor has spread to the larynx, front part of the roof of the mouth, lower jaw, or muscles that move the tongue or are used for chewing.

In stage IVB - The tumor surrounds the carotid artery or has spread to the muscle that opens the jaw, the bone attached to the muscles that move the jaw, nasopharynx or base of the skull. Cancer may have spread to one or more lymph nodes (which can be any size) or may be any size and has spread to one or more lymph nodes that are larger than six centimeters.

In Stage IVC - The tumor may be any size and has spread beyond the oropharynx to other parts of the body.

Treatment and Side Effects Management

Different types of treatment are available for patients with oropharyngeal cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. (A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer.)

Your treatment options depend on the stage of cancer, your overall health and your preferences about treatment. In metastatic disease, the location and extent of the oropharyngeal cancer is also an important consideration.

You do not have to rush to make a decision, so consider the options carefully. Research shows that cancer survivors of all educational levels and backgrounds can have a hard time communicating with their health care team. One of the best ways to improve communication with your health care team is to prepare your visits so that you can best make use of the time.

A treatment plan is a way to deal with both the short and long term goals of managing your oropharyngeal cancer. There are several treatment options for oropharyngeal cancer, depending on the cancer stage and the patient’s age and general health. Patients have time for second opinions and to talk through all of their options with their doctors and develop a treatment plan that best fits their needs.

Learn About Standard Treatment Options