What is mouth cancer?

Mouth cancer is also known as oral cancer. It is one of the most common types of head and neck cancer. It can start in any part of the mouth.

The mouth

The mouth may also be called the oral cavity. It includes the:

  • lips
  • front part of the tongue, called the oral tongue
  • floor of the mouth, under the tongue
  • inside the cheek
  • roof of the mouth, called the hard palate
  • area behind the wisdom teeth
  • upper and lower gums.

The most common places for mouth cancer to develop are on the side of the tongue and the floor of the mouth.

The mouth and tongue

Related pages

Booklets and resources

Signs and symptoms of mouth cancer

The most common symptom of mouth cancer is a mouth ulcer or sore that does not heal in 3 weeks. The areas that may be affected include the:

  • inside of the cheeks
  • roof of the mouth
  • lip
  • gum
  • tongue.

If you have an ulcer or sore, your GP may refer you to see a specialist within 2 weeks. This is called an urgent referral. You can read more about other urgent referral symptoms in our information about the signs and symptoms of head and neck cancer.

Different symptoms of mouth cancer include:

  • a lump or thickening in the mouth or on the lip
  • difficulty or pain with chewing, swallowing or speaking
  • bleeding or numbness in the mouth
  • bad breath (halitosis)
  • loose teeth or dentures that do not fit well anymore
  • a lump in the neck
  • red patches (erythroplakia) or white patches (leukoplakia) that do not go away – can be an early sign of cancer.

These symptoms can be caused by other conditions. But it is important to have them checked by your doctor or dentist.

We have more detailed information about the symptoms of head and neck cancer.

Related pages

Causes and risk factors of mouth cancer

The main causes of mouth cancer are:

  • smoking or chewing tobacco
  • drinking large amounts of alcohol.

Your risk of developing mouth cancer is higher if you do both.

Other things that may increase your risk of mouth cancer are:

  • chewing betel quid (paan), gutkha or pan masala (even if it does not have tobacco in it)
  • having medical problems that cause a weak immune system
  • eating an unhealthy diet without enough fresh fruit and vegetables
  • long-term ultraviolet light exposure (from sunlight, sunbeds or sunlamps), which increases the risk of lip cancer.

Having one or more risk factors does not mean you will get mouth cancer. Also, having no risk factors does not mean you will not develop mouth cancer.

Diagnosis of mouth cancer

You usually start by seeing your GP or dentist. They will examine your mouth closely. If they think your symptoms could be linked to cancer, they will refer you to a specialist doctor.

You may see an oral and maxillofacial specialist (OMFS). Or you may see an ear, nose and throat (ENT) specialist. You usually see a specialist within 2 weeks.

The specialist doctor asks about your symptoms and general health. They check your mouth using a small mirror and bright light. If your only symptom is a lump in your neck, you may be referred to a hospital that has a neck lump clinic.

You may have some of the following tests to diagnose mouth cancer:

  • Nasendoscopy

    A nasendoscope is a thin, flexible tube with a light and camera on the end. It allows your doctor to look inside your nose, the back of your nose and your throat.

  • Biopsy

    To make a diagnosis, your doctor needs to remove a small piece of tissue or some cells (biopsy) from the area that looks abnormal. Your doctor may take a biopsy while they are examining you with the nasendoscope. Or they might arrange for you to have a general anaesthetic to take the biopsy.

    To make a diagnosis, your doctor needs to remove a small piece of tissue or some cells (biopsy) from the area that looks abnormal. Your doctor may take a biopsy while they are examining you with the nasendoscope. Or they might arrange for you to have a general anaesthetic to take the biopsy.

    A doctor called a pathologist looks at the sample under a microscope to check for cancer cells.

  • Ultrasound scan of the neck

    If you have a lump or a swelling in your neck, you usually have an ultrasound scan of the area. This uses soundwaves to produce a picture of your neck and nearby lymph nodes.

  • Fine needle aspiration (FNA) of the lymph nodes

    You may have a fine needle aspiration test to see whether there are any cancer cells in the lymph nodes in the neck. But it can also be used to take samples from the mouth. The doctor passes a fine needle into the lump. They withdraw (aspirate) some cells into the syringe. Sometimes they use an ultrasound scan to help the doctor to guide the needle into the area.

We have more information about tests for head and neck cancer.

Further tests for mouth cancer

These tests may be used to help diagnose mouth cancer and to check whether it has spread.

  • CT scan

    A CT scan takes a series of x-rays, which build up a three-dimensional (3D) picture of the inside of the head and neck.

  • MRI scan

    An MRI scan uses magnetism to build up a detailed picture of areas of the head and neck.

Waiting for test results can be a difficult time. We have more information that can help.

Staging and grading of mouth cancer

The results of your tests helps your doctors find out more about the size, depth and position of the cancer and whether it has spread. This is called staging.

The grade of the cancer describes how the cancer cells look under the microscope. This gives an idea of how quickly the cancer might develop.

Knowing the grade and stage helps your doctors plan the best treatment for you.

The most commonly used staging systems for mouth cancer are the TNM and number staging systems.

TNM staging system

TNM stands for tumour, node and metastases.

Tumour (T)

T describes the size of the tumour and whether it has grown into the surrounding areas. It is numbered 0 and 4 depending on the size and extent of the tumour.

  • T0 means there are no signs of a tumour in the mouth, but there may be abnormal cells that are pre-cancerous.
  • T1 the tumour is smaller than 2cm and less than 5mm deep.
  • T2 the tumour may be smaller than 2cm and deeper than 5mm but not deeper than 10mm. Or, tumours may be larger than 2cm but less than 4cm and not deeper than 10mm.
  • T3 the tumour may be larger than 2cm but less than 4cm and are deeper than 10mm. Or, tumours may be larger than 4cm but not deeper than 10mm.
  • T4 the tumour may be larger than 4cm and deeper than 10mm. Or, the tumour may have spread into nearby areas, such as muscles or bones.

Nodes (N)

Nodes describes whether the cancer has spread to the lymph nodes.

Metastases (M)

M describes whether the cancer has spread to another part of the body (called metastatic cancer).

The number staging system combines all the information from TNM staging and gives it a number from 1 to 4.

Read more about this in our information about staging and grading of head and neck cancer.

Grading of mouth cancer

A doctor looks at a sample of the cancer cells under a microscope to find out the grade of the cancer.

  • Grade 1 or low grade – the cancer cells look like normal cells and usually grow slowly.
  • Grade 2 and 3 – the cancer cells look different to normal cells and are slightly faster growing.

Treatment for mouth cancer

Treatment for mouth cancers include surgery, radiotherapy and chemotherapy. Sometimes targeted therapies and immunotherapies might be used

  • Surgery

    Surgery is the main treatment for early-stage mouth cancer. It is often the only treatment needed to remove an early-stage mouth cancer. Sometimes some lymph nodes in the neck may also be removed.

  • Radiotherapy

    Radiotherapy uses high-energy rays to destroy the cancer cells, while doing as little harm as possible to normal cells. Radiotherapy is often used after surgery to reduce the risk of the cancer coming back. If surgery is not possible, you usually have radiotherapy instead of surgery.

    It can be used on its own but is often given with chemotherapy (called chemoradiation).

  • Chemotherapy

    Chemotherapy uses anti-cancer (cytotoxic) drugs to destroy cancer cells. The chemotherapy drugs most often used to treat mouth cancer are cisplatin and fluorouracil (5FU).

  • Chemoradiation

    Chemoradiation or chemoradiotherapy is when you have chemotherapy and radiotherapy together. Chemotherapy can make the cancer cells more sensitive to radiotherapy treatment.

  • Targeted therapies

    Targeted therapy work by targeting something in or around the cancer cell that is helping it grow and survive. Cetuximab is the most commonly used targeted therapy to treat mouth cancer.

We have more information about how treatments are used to treat mouth cancer

You may have some treatments as part of a clinical trial.

After mouth cancer treatment

You have regular follow-up appointments after treatment. You may also have regular follow-up appointments with your multidisciplinary team (MDT), including,a speech and language therapist (SLT), dietitian, restorative dentist and dental hygienist and sometimes a physiotherapist.

If you have any problems or notice new symptoms between appointments, let your doctor or nurse know as soon as possible.

Long-term or late effects

Some treatment side effects may take a long time to improve after treatment finishes, or they may become permanent. These are called long-term effects. Other side effects can develop months or even years after treatment has finished. These are known as late effects. We have more information about long-term and long-term and late effects of head and neck cancer treatment.

Sex life

Head and neck cancer and its treatment can sometimes have an effect on your sex life.

If you are worried about this, talk to your doctor or nurse. You can read about things that may help in our information on cancer and sex.


Some cancer treatments can also affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

We have more information about:

Well-being and recovery

Even if you already have a healthy lifestyle, you may choose to make some positive lifestyle changes during and after treatment. For example, if you smoke or drink alcohol, it is best to avoid smoking or reduce the amount of alcohol.

Eating well and keeping active can improve your health and well-being. It can also help your body recover. Your dietitian can help with any difficulties you might have with eating after treatment.

Getting support

It may take several months to recover from treatment. It can be hard if treatment has changed your appearance, how you eat or drink, or your voice. This may also affect your body image but there are ways to help you to manage any changes.

You may still be coping with difficult feelings. Talking to your family and friends or health professionals about how you feel can help them know how to support your well-being.

There are also national support groups that you may find helpful:

  • The Mouth Cancer Foundation
    The Mouth Cancer Foundation
    gives information and support to people affected by head and neck cancers.
  • Changing Faces
    Changing Faces
    offers advice and information to anyone who is affected by a change in their appearance.
  • The Swallows Head and Neck Cancer Support Group
    The Swallows
    offers a 24-hour support line to anyone affected by head and neck cancer.
  • Salivary Gland Cancer UK
    Salivary Gland Cancer UK supports people with rare salivary gland cancers, such as adenoid cystic carcinoma, ACC, and unknown carcinoma.

Macmillan is also here to support you. If you would like to talk, you can:

Related pages

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr Chris Alcock, Consultant Clinical Oncologist.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

Date reviewed

Reviewed: 01 March 2022
Next review: 01 March 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.