A small sample of affected tissue will need to be removed and checked for cancerous cells. This is known as a biopsy.
The main methods used to do a biopsy in cases of suspected mouth cancer are:
- an incision or punch biopsy
- a fine needle aspiration with cytology
- a nasendoscopy
- a panendoscopy
The samples taken during a biopsy are examined under a microscope by a specialist doctor (pathologist).
The pathologist then sends a report to the surgeon to tell them whether it's cancer and, if it is, what type and what grade it is.
Incision and punch biopsy
An incision biopsy is usually done using local anaesthetic if the affected area is easily accessible, such as on your tongue or the inside of your cheek.
After the area has been numbed, the surgeon will cut away a small section of affected tissue.
The wound is sometimes closed with dissolvable stitches. The procedure is not painful, but the affected area may feel sore afterwards.
A punch biopsy is where an even smaller piece of tissue is removed and no stitching is used.
Fine needle aspiration cytology
A fine needle aspiration cytology (FNAC) may be used if you have a swelling in your neck that's thought to be a secondary from the mouth cancer.
It's usually done at the same time as an ultrasound scan of the neck.
FNAC is like having a blood test. A very small needle is used to draw out a small sample of cells and fluid from the lump so it can be checked for cancer.
The procedure is very quick and the discomfort felt is the same as with a blood test.
A nasendoscope is a long, thin, flexible tube with a camera and a light at one end. It's guided through the nose and into the throat.
It's usually used if the suspected cancer is inside your nose, throat (pharynx) or voice box (larynx).
A nasendoscopy takes about 30 seconds. Local anaesthetic may be sprayed into your nose and throat first, to reduce any discomfort.
Occasionally, tissue may be taken using a telescopic punch biopsy.
A panendoscopy is similar to a nasendoscopy, but uses a larger tube (scope) which give better access. You will be given a general anaesthetic before the procedure because the scope would be too uncomfortable if you were awake.
A pandendoscopy can also be used to remove small tumours.
If the biopsy confirms that you have mouth cancer, you'll need further tests to check what stage it's reached before any treatment is planned.
These tests usually involve having scans to check whether the cancer has spread into tissues next to the primary cancer, such as the jaw or skin, as well as scans to check whether it has spread into the lymph glands in your neck.
It's rare for mouth cancer to spread further than this, but you may also have scans to check the rest of your body.
Tests you may have include:
Your X-rays and scans will be looked at by a specialist doctor called a radiologist. They'll write a report which plays a major part in making decisions about staging.
After these tests have been done, it should be possible to determine the stage and grade of your cancer.
Staging and grading
Staging is a measure of how far the cancer has spread. The TNM system of staging is used for staging mouth cancer:
- T relates to the size of the tumour (also called the primary cancer) in the mouth; T1 is the smallest and T4 is the largest or most invasive
- N is used to show whether there are secondaries (metastases) in the neck lymph glands; N0 means none have been found during examination or on scans, and N1, N2 and N3 indicate the extent of neck secondaries
- M refers to whether there are secondaries elsewhere in the body
Grading describes how aggressive the cancer is and how fast it's likely to spread in future.
The 3 grades of mouth cancer are:
- low grade – the slowest
- moderate grade
- high grade – the most aggressive
Staging and grading will help determine whether you have:
- early mouth cancer, which usually curable with an operation
- intermediate mouth cancer, which still has a high chance of a cure, but will almost certainly need a more complex operation and radiotherapy
- advanced mouth cancer, which has a lower chance of a cure and will need all 3 types of treatments (surgery, radiotherapy and chemotherapy)
Staging and grading cancer will help your multidisciplinary care team decide how you should be treated.
Find out more from Cancer Research UK about staging and grading of mouth cancer.