Oral cancer is any cancerous tissue growth located in the oral cavity (mouth), on the lip, and the oropharynx (the part of the throat at the back of the mouth).
Oral cancer most commonly involves:
Most oral cancers look very similar under the microscope and are called “squamous cell” carcinomas. These are malignant and tend to spread rapidly.
- the tongue, which accounts for 20% to
25% of cases;- floor of the mouth, 15%; the lip, 10% to 15%; and
- minor salivary glands, 10% to 15%.
Squamous Cell Carcinoma
Squamous epithelium is the tissue that lines the mouth, throat, tongue and tonsils. These tissue cells are irregularly shaped and very flat. Carcinoma is any malignant cancer that arises from the epithelial cells. Carcinomas invade surrounding tissues and organs and may “metastasize”, or spread, to lymph nodes and other sites.
Metastasis is the spread of a disease from one organ or body part to another non-adjacent organ or body part. Only malignant tumor cells and infections have the capacity to metastasize. Cancer cells can "break away", "leak", or "spill" from a primary tumor, enter lymphatic and blood vessels, circulate through the bloodstream, and settle down to grow within normal tissues elsewhere in the body.
Oral Cancer is often detected late in development, when the possibility of metastasis is much greater. Like most cancers, cancer of the lip and oral cavity is best treated when found early – when cure rates are greater than 80%.
Oral Cancer frequently has no symptoms; however, when symptoms do occur, the most common include:
- A sore or ulcer on the lip or in the mouth that does not heal
- A lump on the lip, or in the mouth, or in the neck
- A white or red patch on the gums, tongue, or lining of the mouth
- Unusual bleeding, pain, or numbness in the mouth
- Oral pain that does not go away
- Difficulty or pain with chewing, swallowing, or jaw opening
- Swelling of the jaw that causes dentures to fit poorly or become uncomfortable
- Tooth loosening
- Bad breath
- Sensory loss in the face
- Abnormal taste in the mouth
- Tongue problems
Risk Factors/Causes
(in North America)
1. TOBACCO & ALCOHOL
The most recognized risk cause for oral cancer is the use of tobacco (smokeless and “chew” included) and alcohol. And yet, while tobacco and alcohol consumption continue to decrease, oral cancer incidences have increased. Why? New studies point to HPV-16 and 18.
2. SEXUALLY TRANSMITTED HPV-16 and 18 Exposure to the HPV-16 virus (human papilloma virus) is the fastest growing risk factor for oral cancer. This is the same virus responsible for the majority of cervical cancers in women. The virus presents up to a 5 fold increase in incidence under the age of 40, which means all patients, both male and female, over the age of 17 should be screened annually, as the CDC indicates that 50% of people over the age of 17 have been sexually active, and therefore have exposed themselves to HPV. The FDA estimates that 70% of cervical cancers are associated with HPV-16 or 18. New studies have confirmed a significant link to oral cancer as well. In the oral environment these manifest themselves primarily in the back (posterior) regions such as the base of the tongue, back of the throat (oropharynx), tonsils and tonsillar pillars.
Determination of the stage of cancer in the lip or oral cavity is important in order to plan the best course of treatment. The most common staging system used for oral cancer is the American Joint Committee on Cancer (AJCC) TNM system. The TNM system refers to: (T) the tumor features -size and invasion level; (N) the lymph nodes involved - lymph nodes are part of the body immune system; (M) the cancer metastasis - metastasis stage is the last developmental cancer stage when the cancer has spread to distal organs (organs situated far from the origin point).
