Cancer.gov
Oral cancer, also known as mouth cancer, is a type of head-and-neck cancer and is the term used for any cancerous tissue growth located in the oral cavity. There are several types of oral cancer, 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, gingiva (gums), lips, or palate (roof of the mouth). If a tumour grows directly on the cheek bone, it is known as an osteosarcoma.
Oral cancer is relatively rare: in Belgium around 1,750 new patients are registered annually on a total of over 67,000 cancer patients. Around two thirds of oral cancer patients are male, and the disease is most often found in people over 45 years old.
A beginning oral tumour can manifest itself as a swelling or as lesions in the mouth or as white or red spots. Another warning sign is when teeth get loose or dentures no longer fit properly. When the cancer progresses, patients may experience pain that radiates to their neck, jaw or ears. They may also suffer from bleeding, bad breath and experience difficulty with opening their mouth. Speech impediments and numbness in the tongue are also common symptoms associated with oral cancer.
The tumours occur most frequently along the line where the upper and lower jaws meet, but they can also form under the tongue or into the bone of the lower jaw. If the tumour occurs in the mucous membrane in the inner cheek, it may cause swelling of the cheek.
Of all the risk factors associated with oral cancer, smoking and consuming alcohol are by far the most common. Most oral cancer patients have a history of smoking or consuming alcohol. When patients have done both, the risk of contracting oral cancer becomes even larger. Both habits also negatively impact results of cancer treatment and enlarge the risk of the cancer recurring at a later stage.
Other risk factors are:
If a patient presents with possible symptoms of oral or throat cancer, a GP will in all likelihood prescribe medication against known throat problems, but when symptoms persist the patient may be referred to a throat-nose-ear specialist. Occasionally, a patient is referred by a dentist.
The throat-nose-ear specialist will examine the oral cavity and check the neck area for possible metastases. If oral or throat cancer is suspected, a laryngoscopy and/or a biopsy will follow. A laryngoscopy is a procedure during which a flexible tube with a micro camera is inserted into the throat. A biopsy is a procedure that involves removal – under anaesthetic – of a tissue sample, which can then be examined in a laboratory.
If the cancer diagnosis is established, further tests are required in order to determine the disease stage, which is vital when it comes to deciding on a treatment strategy. These tests generally involve X-rays, MRI scans and CT scans. Oral cancers are graded using the TNM staging system, in which T stands for tumour, specifically its size and whether it has spread, N stands for nearby lymph nodes and M stands for distant metastasis.
There are four stages:
The differentiation of the tumour is an important factor in establishing a prognosis and treatment. This can be determined on the basis of a biopsy. A biopsy involves the removal of a small bit of tissue that can be examined under a microscope. Differentiation determines the degree of mutation in the cancerous cells.
When all the characteristics of the tumour have been established, specialists will come up with a treatment strategy. In the case of oral cancer, this commonly involves radiation, chemotherapy, surgery or light-therapy. It is important to cause as little damage to the mucous membrane as possible. The mucous membrane also encapsulates the larynx, which contains the vocal cords. Small tumours will primarily be treated with radiotherapy, but large tumours can necessitate surgery and even removal of the larynx. Surgery is followed up by chemotherapy and radiation.
When the tumour is relatively thin (no thicker than half a centimetre), photodynamic therapy (PDT) is an option. Patients are injected with a chemical that concentrates around the tumour. By targeting the area with laser light, a chemical reaction is triggered that kills off the cancerous cells.
Metastases in the neck area can be removed surgically, sometimes followed up by radiation. If the tumour has spread so much that curing the patient is no longer considered an option, radiation and chemotherapy can be offered as part of a palliative care program. Targeted therapy can also be an option in an advanced disease with the use of EGFR inhibitors.
Top
