Oral Cancer

Pre Cancerous Lesions

The oral cavity (mouth) and the upper part of the throat (pharynx) have roles in many important functions, including breathing, talking, chewing, and swallowing. Many different cell types make up these different structures. Cancer occurs when normal cells undergo a transformation whereby they grow and multiply without normal controls. As the cells multiply, they form small abnormalities called lesions. Cancerous oral lesions are life- threatening cell changes in the mouth. These lesions are often detected by a dentist at a routine dental examination and give you a better chance for a cure. There are three pre-cancerous conditions that occur frequently in the oral cavity.

Leukoplakia (white patch): This is the most common condition that occurs in the oral cavity and is adjacent to the place where the tobacco quid is kept. It appears as a white patch that cannot be rubbed off. These patches are gray or yellowish- white in colour and in some cases when tobacco is heavily used, these patches take on a brownish appearance. This is a dangerous sign since they can convert themselves into full-blown cancer without the patient being aware of it.

Erythroplakia (red lesion): This is characterised by red velvety patch, which is not associated with any trauma or inflammation. It may present with or without leukoplakia. This lesion is easily missed out but is considered to have great malignancy potential.

Oral Submucous fibrosis: A rare disorder involving inflammation and progressive fibrosis of tissues inside the mouth. The condition starts with redness, blistering and ulceration inside the mouth that is eventually replaced with stiff fibrous tissue as it heals. As the disease progresses, the jaws become rigid to the point that the sufferer is unable to open his mouth. The person affected suffers burning sensation on eating spicy food. This is a progressive lesion in which the opening of the mouth becomes progressively limited, and later on even normal eating becomes difficult. It occurs almost exclusively in India and Indian communities living abroad. The disorder is often associated with chewing betel nuts.

Signs and Symptoms of precancerous and cancerous oral lesions may include:

• A sore in the mouth that doesn't heal within 3 weeks.
• White or red lesions or ulcers on the tongue, gums or lining of the mouth that don't go away.
• Tenderness or pain in the mouth that persists.

Tumour

These pre-cancerous lesions eventually form a mass called a tumour. A ‘tumour’ is an abnormal mass of tissue that grows from normal cells. The process of cell division in the body is very systematic. A tumour is the name for a solid lesion formed by an abnormal growth of cells (termed neoplastic) which looks like a swelling. Tumor is not synonymous with cancer. A tumor can be benign, pre-malignant or malignant, whereas cancer is by definition malignant.

Benign Tumours: Do not invade tissues around them. They do not spread to other parts of the body and are usually harmless. The chances of recurrence after the excision of the tumour is very rare.

Malignant Tumours: Tumours are cancerous only if they are malignant. This means that they are life threatening because of their uncontrolled growth, they encroach on and invade neighboring tissues and organs. Malignant tumors may spread to neighboring tissues by direct invasion or by traveling along lymphatic vessels and nerves or through the blood stream. This process of invading and spreading to other organs is called metastasis.

Oral cancer is a sub-type of head and neck cancers. It is the cancerous tissue growth in any part of oral cavity or oropharynx. Most oral cancers initiate from the tongue and floor of the mouth.

Causative Factors

• Tobacco : Tobacco use accounts for most oral cancers. Smoking cigarettes, cigars, or pipes; using chewing tobacco; and dipping snuff are all linked to oral cancer. The use of other tobacco products (such as bidis and kreteks) also increase the risk of oral cancer. Heavy smokers who use tobacco for a long time are most at risk. The risk is even higher for tobacco users who drink alcohol heavily. In fact, three out of four oral cancers occur in people who use alcohol, tobacco, or both alcohol and tobacco.
• Alcohol : People who drink alcohol are more likely to develop oral cancer than people who don't drink. The risk increases even more if the person both drinks alcohol and uses tobacco.
• Sun : Cancer of the lip can be caused by exposure to the sun. Using a lotion or lip balm that has a sunscreen can reduce the risk. Wearing a hat with a brim can also block the sun's harmful rays. The risk of cancer of the lip increases if the person smokes.
• A personal history of head and neck cancer : People who have had head and neck cancer are at increased risk of developing primary head and neck cancer. Smoking increases this risk.

Signs and Symptoms

• A sore mouth that doesn't heal within 3 weeks.
• White or red lesions or ulcers on tongue, gums or lining of the mouth that doesn't heal.
• Tenderness or pain in mouth that persists.
• Difficulty in chewing or swallowing.
• Difficulty in moving jaw or tongue.
• Numbness of the tongue or any area of mouth.
• Swelling of the jaw that causes dentures to fit poorly or become uncomfortable.

Diagnosis

Consult your dentist about any sore or pain in the mouth. He or she will ask questions about your medical and dental history. Your entire mouth, including your lips and teeth, will be checked. A biopsy or other tests may also be done.

• A biopsy is the best way to find out if a lesion is precancerous or cancerous. During a biopsy, the area around the lesion will be numbed. A part of the lesion will then be removed and sent to a lab to be examined under a microscope.
• Other tests helpful in making the diagnosis are staining and cytology. During the former the area around the lesion is stained with a special dye. The dye binds to cancerous cells, staining only these cells. After a few hours, the colour from the dye will disappear. During cytology your dentist may scrape the surface of the lesion to obtain cells. The cells are then sent to a lab, where they are examined for cancer.

Treatment will depend on the nature of the oral lesion. Your dentist can tell you about the treatment, which may include surgery, radiation therapy, Combination therapy (Both surgery and radiation therapy may be used to treat advanced cases of oral cancer.) and Chemotherapy.