A small sample of affected tissue will need to be removed to check for the presence of cancerous cells. This procedure is known as a biopsy.
The main methods used to carry out 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 sent to a specialist doctor called a pathologist, who examines them under a microscope.
They'll report back 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 carried out under local anaesthesia if the affected area of tissue is easily accessible, such as on your tongue or the inside of your mouth.
After the area has been numbed with a local anaesthetic, the surgeon will cut away a small section of affected tissue and remove it with tweezers.
The wound is sometimes closed with dissolvable stitches. The procedure isn't painful, but the affected area can be a little 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 is carried out.
FNA is a bit 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 tissue 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 to reduce any discomfort.
Occasionally, tissue may be taken using a telescopic punch biopsy. Sometimes the surgeon will let you see the images on the computer screen.
A panendoscopy is carried out under general anaesthetic. It's used to investigate the same areas as a nasendoscopy, but uses larger telescopes that would be uncomfortable if you were conscious.
The scopes give better access, so the procedure 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 for spread into the lymph glands in your neck.
It's rare for mouth cancer to spread further than these glands, but you'll also have scans to check the rest of your body.
Tests you may have include:
- an X-ray
- an ultrasound scan
- a magnetic resonance imaging (MRI) scan
- a computerised tomography (CT) scan
- a positron emission tomography (PET) scan
The X-rays and scans will be looked at by a specialist doctor called a radiologist. They'll write a report and put it on the hospital computer system. The report forms a major part of decisions about staging.
After these tests have been completed, 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 deeply 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
The grade 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 – usually curable with a small operation
- intermediate mouth cancer – still has a high chance of a cure, but will almost certainly need a long operation and radiotherapy
- advanced mouth cancer – has a lower chance of a cure and will definitely need all 3 treatments (surgery, radiotherapy and chemotherapy)
Staging and grading your cancer will help your surgeon and multidisciplinary team (MDT) decide how you should be treated.
The Cancer Research UK website has more information about the staging and grading of mouth cancer.