What is mouth and oropharyngeal cancer?
Mouth and oropharyngeal cancer happens when abnormal cells in the mouth and oropharynx divide and grow uncontrollably. Most mouth and oropharyngeal cancers develop in 
. They are called squamous cell (SCC).
Mouth cancer can start in different parts of the mouth. It is sometimes called oral cancer.
Oropharyngeal cancer starts in the oropharynx. This is the part of the throat (pharynx) just behind the mouth. It includes tonsil cancer and cancer of the back part of the tongue (the base of the tongue).
This section is about both mouth and oropharyngeal cancer. If your cancer started on your tongue, you might find it helpful to also look at our information about tongue cancer.
You can also find out more about cancer that starts in the tonsils.
The mouth
The medical term for the mouth is the oral cavity. Mouth cancer can start anywhere in the oral cavity. This includes the:
- lips
- inside lining of the cheeks and lips (buccal mucosa)
- front two thirds of the tongue
- gums (gingiva)
- floor of the mouth
- roof of the mouth (hard palate)
- area behind the wisdom teeth (retromolar trigone)
The mouth and oropharynx help us breathe, talk, eat, chew and swallow.
The oropharynx
The medical term for the throat is the pharynx. The pharynx is divided into 3 parts:
- oropharynx
- nasopharynx
- laryngopharynx
The oropharynx is the part of the throat just behind the mouth. Cancer starting in this area is called oropharyngeal cancer (pronounced oar-oh-fah-rin-jee-al).
The oropharynx includes the:
- back one third of the tongue
- soft area at the back of the roof of the mouth (soft palate)
- tonsils and 2 ridges of tissue in front of and behind the tonsils (tonsillar pillars)
- back wall of the throat
Lymph nodes in your neck
Lymph nodes are small bean shaped glands that are part of the lymphatic system.
There are major groups of lymph nodes in your neck. Cancers starting in the mouth and oropharynx can spread to these because they are close by.
Your doctor examines your mouth and neck. You might also have tests to check for cancer in nearby lymph nodes.
You might have an operation to remove lymph nodes from the same side of the neck as the cancer. Rarely the surgeon might remove them on both sides. These operations are called neck dissections.
Cancer that starts in the lymph nodes is called lymphoma. This is very different to a mouth or oropharyngeal cancer that has spread to the lymph nodes.
What is throat cancer?
The term throat cancer can be confusing because people use it to mean different types of cancer. People use the term to include the:
- 3 parts of the pharynx (oropharynx, nasopharynx, laryngopharynx)
- thyroid
- voice box (larynx)
- food pipe (oesophagus)
To avoid confusion, it is important to know the exact type of cancer you have. Cancers are treated according to where they start in the body. Ask your doctor if you do not know the name of the type of throat cancer you have.
Who gets mouth and oropharyngeal cancer?
Oral cancer is more common in men than women. Research shows that 1 in 55 men and 1 in 108 women will be diagnosed with oral cancer at some point in their life.
Most HPV positive and non HPV oropharyngeal and oral cancers happen in people that are middle aged or elderly.
The human papillomavirus (HPV) and oropharyngeal cancer
In the UK, more than 50 out of 100 (more than 50%) squamous cell oropharyngeal cancers are linked to the human papillomavirus (HPV). This is a common virus that causes no harm in most people. But in some people, the virus can cause changes in the throat, making them more likely to become cancerous in the future.
In recent years, there has been an increase of HPV positive oropharyngeal cancer.
Doctors test your oropharyngeal cancer cells to see if they contain the HPV virus. This affects the stage of your cancer and your outlook (prognosis). Oropharyngeal cancers containing HPV tend to have a better outlook than cancers that don’t.
How common is mouth and oropharyngeal cancer?
Each year, around 8,900 new cases of mouth and oropharyngeal cancer are diagnosed in the UK.
