Mouth cancer, otherwise known as oral cancer is considered to be a subtype of head and neck cancer. Oral cancer is any cancerous tissue growth that occurs in the oral cavity. It may arise as a primary lesion originating in any of the tissues in the oral cavity. There are several types of oral cancers, but around 90% are squamous cell carcinomas, originating in the tissues that line the mouth and lips. Oral or mouth cancer most commonly involves the tongue. It may also occur on the floor of the mouth, cheek lining, gums, lips or palate (roof of the mouth).
- In the early stages of oral cancer, symptoms are hard to detect. A word of caution for smokers as well as heavy drinkers: it would be advisable to go for regular check-ups to your nearest dentist. When signs and symptoms finally start manifesting, they can include the following:
- Patches on the lining of the mouth or tongue, usually red or red and white in colour
- Mouth ulcers that refuse to go away
- A swelling in the mouth that persists for over three weeks
- A lump or thickening of the skin or lining of the mouth
- Pain when swallowing
- Loose teeth (tooth) for no clear reason
- Jaw pain
- Jaw stiffness
- Sore throat
- Painful tongue
- A hoarse voice
- Pain in the neck that does not go away
- Unexplained weight loss
- Unusual changes in the sense of taste
- The lymph nodes (glands) in the neck become swollen
- Unexplained bleeding in the mouth
- Unexplained numbness, loss of feeling or pain/tenderness in any area of the face, mouth or neck
CAUSES AND RISK FACTORS OF MOUTH CANCER
There are certain factors that may increase the chances of an individual contracting mouth cancer. They can be considered to be either causes or risk factors or both. Some of them are:
Smoking and Drinking: Smoking and drinking contain substances that are carcinogenic in nature, which means they contain chemicals that can damage the DNA in cell, leading them to become cancerous eventually. The risk of mouth cancer increases significantly in somebody who is both a heavy smoker and heavy drinker. Somebody who smokes 40 cigarettes per day and consumes an average of 30 pints of beer a week is 38 times more likely to develop oral cancer compared to other people.
Betel nuts: Betel nuts are mildly addictive seeds taken from the betel palm tree. They have a stimulant effect similar to coffee. Betel nuts also have a carcinogenic effect, which can increase the risk of mouth cancer. This risk is made worse as many people enjoy chewing betel nuts along with tobacco. Due to the tradition of using betel nuts, rates of mouth cancer are much higher in ethnic Indian and Sri Lankan communities than in the population at large.
Smokeless tobacco: Smokeless tobacco is a general term used to refer to a range of products, such as:
- chewing tobacco
- snuff – powdered tobacco designed to be snorted
Smokeless tobacco products are not harmless, as many people mistakenly assume, and many increase your risk of developing mouth cancer, as well as other cancers, such as liver cancer, pancreatic cancer and oesophageal cancer.
Human Papilloma Virus (HPV): It is the name of a family of viruses that affect the skin and moist membranes that line your body, such as those in your cervix, anus, mouth and throat. You can contract a HPV infection by having sexual contact with a person already infected – you do not have to have sex; just close skin-to-skin contact. Infection with some types of HPV can cause abnormal tissue growth and other changes to the cells, which can lead to the development of cervical cancer. There is evidence that some types of HPV infection could also cause abnormal tissue growth inside the mouth, triggering some cases of mouth cancer.
Diet: There is evidence that a diet high in red meat, processed food and fried food can increase your risk of developing mouth cancer.
Poor oral hygiene: There is evidence that poor oral hygiene, such as having tooth decay, gum disease, not brushing your teeth regularly and having ill-fitted dentures (false teeth) can increase your risk of mouth cancer.
GERD (gastro-oesophageal reflux disease): People with this digestive condition where acid from the stomach leaks back up through the gullet (oesophagus) have a higher risk of oral cancer.
Exposure to certain minerals and chemicals – especially asbestos, sulphuric acid and formaldehyde increase the risk of mouth cancer.
The normal tests that a doctor does on the patient in order to confirm whether the symptoms are due to oral cancer are:
- Gum biopsy
- Tongue biopsy
In order to determine if a lesion is cancerous the doctor will have to remove a small sample of affected tissue to check for the presence of cancerous cells. This procedure is known as a biopsy.
The three main methods which are used to carry out a biopsy in cases of suspected mouth cancer are:
A punch biopsy is used when the suspected affected area of tissue is in an accessible place, such as your tongue or the inside of your mouth. The area is injected with a local anaesthetic to numb it. The doctor will then cut away a small section of affected tissue and remove it with tweezers. The procedure is not painful.
Fine Needle Aspiration (FNA)
A Fine Needle Aspiration (FNA) is a type of biopsy used if it is suspected that a swelling in your neck is the result of mouth cancer. During an FNA, the doctor inserts a sharp needle into the lump and draws out a small sample of tissue and fluids. The sample is then checked for cancerous cells.
A panendoscopy is a procedure used to obtain a biopsy when the suspected tissue is at the back of your throat or inside one of your nasal cavities. The doctor uses an instrument called a panendoscope. This is a long thin tube that contains a camera and light source. The panendoscope is guided through your nose, and then used to remove a small section of tissue for the biopsy. The panendoscope can also check whether cancer has spread from your mouth to further down your throat, such as your larynx (voice box), oesophagus (gullet) or trachea.
If the biopsy results are positive, further tests will have to be carried out to check how advanced it is and how far it has spread. These tests will include anyone of the following procedures:
It is a medical imaging technique used in radiology to visualise internal structures of the body in detail. MRI can create more detailed images of the human body than are possible with x-rays. An MRI scanner is a device in which the patient lies within a large, powerful magnet where the magnetic field is used to align the magnetisation of some atomic nuclei in the body, and radio frequency magnetic fields are applied to systematically alter the alignment of this magnetisation. This causes the nuclei to produce a rotating magnetic field detectable by the scanner and this information is recorded to construct an image of the scanned area of the body. By using gradients in different directions, 2D images or 3D volumes can be obtained in any arbitrary orientation. MRI provides good contrast between the different soft tissues of the body, which makes it especially useful in imaging the brain, muscles, the heart and cancers compared with other medical imaging techniques such as Computed Tomography (CT) or x-rays. Unlike CT scans or traditional x-rays, MRI does not use ionising radiation.
A CT scanner emits a series of narrow beams through the human body as it moves through an arc, unlike an x-ray machine which sends just one radiation beam. The final picture is far more detailed in a CT scan than in an x-ray.
Inside the CT scanner there is an x-ray detector that can see hundreds of different levels of density. It can see tissues inside a solid organ. This data is transmitted to a computer, which builds up a 3-D cross-sectional picture of the part of the body and displays it on the screen.
Sometimes a contrast dye is used because it shows up much more clearly on the screen. If a 3-D image of the abdomen is required, the patient may have to drink a barium meal. The barium appears white on the scan as it travels through the digestive system. If images lower down the body are required, such as the rectum, the patient may be given a barium enema. If blood vessels are the target images, the barium is injected.
The accuracy and speed of CT scans may be improved with the application of spiral CT. The x-ray beam takes a spiral path during the scanning – it gathers continuous data with no gaps between images. For a spiral scan of the chest, for example, the patient is asked to hold his/her breath for a few seconds.
PET scan is a nuclear medical imaging technique that produces a three-dimensional image or picture of functional processes in the body. The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide (tracer), which is introduced into the body on a biologically active molecule. Three-dimensional images of tracer concentration within the body are then constructed by computer analysis. In modern scanners, three dimensional imaging is often accomplished with the aid of a CT x-ray scan performed on the patient during the same session, on the same machine.
Depending on the stage of the mouth cancer, the doctor will recommend anyone of the following methods to treat cancerous cells:
The most common treatment used to treat mouth cancer is surgery. The type of operation depends on the size of the cancer and its site. Sometimes surgery is aimed at curbing the cancer by removing it all. Sometimes it is used to relieve symptoms if the cancer is at an advanced stage (palliative surgery). Laser surgery may sometimes be used to remove small mouth cancers. This may be combined with a light-sensitive drug in treatment known as photodynamic therapy (PDT).
Radiotherapy otherwise known as radiation therapy, is a treatment which uses high-energy beams of radiation which are focused on cancerous tissue. This kills cancer cells, or stops cancer cells from multiplying.
- External radiotherapy: This is where radiation is targeted on the cancer from a machine. (This is the common type of radiotherapy which is used for many types of cancer.)
- Internal radiotherapy:This treatment involves placing small radioactive wires next to the cancer site for a short time and removing it later.
Chemotherapy uses anti-cancer drugs to kill cancer cells, or to stop them from multiplying. Chemotherapy may be used in combination with radiotherapy or surgery. Chemotherapy may also be advised if the cancer has spread to other areas of the body..
The extent of treatment for oral cancer depends on a number of factors. Among them are the location, size, type and extent of the tumour and stage of the disease. Treatment may involve surgery, radiation therapy or a combination.