Oral cancer is a type of cancer which begins in the linings of the mouth and inside the lips, most commonly as squamous cell carcinoma. Oral cancers are most often caused by tobacco use (including cigarette smoking). Every year, about 35,000 Americans receive an oral cancer diagnosis, and 8000 die from the disease. Most diagnoses occur at a late stage, even though the cancer is highly detectable in its early stages, when it could be more effectively treated.
- Causes of Oral Cancer and Risk Factors for Oral Cancer -
About three-quarters of oral cancer cases occur among tobacco users (those who smoke cigarettes or cigars, and/or chew tobacco). Cigarette smoking is known to increase the risk of contracting a large number of cancers, especially lung cancer but also including oral cancer and stomach cancer. This is the leading cause of oral cancer in older people. Heavy alcohol drinking can increase the risk of oral cancer, and alcohol and tobacco use together cause the greatest risk.
Many of the remaining cases of oral cancer are now believed to occur as a consequence of infection by human papillomavirus (HPV), the virus that causes genital warts. HPV has previously been implicated in causing cervical cancer in women, and several of those strains responsible for cervical cancer are now targeted by vaccines. However, when HPV infection occurs via the mouth through oral sex, the same mutations which lead to cervical cancer may also lead to cancer in the mouth.
In addition, there are several demographic factors known to affect the chances of getting oral cancer. Most diagnoses occur after age 40, although the average age at diagnosis has been creeping downwards. Men remain twice as likely as women to be diagnosed with oral cancer. African-Americans are also at greater risk than white Americans, with both a higher rate of diagnosis as well as a lower survival rate following diagnosis.
- Diagnosis and Treatment of Oral Cancer -
It is relatively easy to identify a suspected cancerous growth in the mouth. A doctor or a dentist will search for lesions or ulcers on the inside of the lips, on the lining of the mouth, or on the tongue. Once a suspicious area is identified, a small tissue sample can be removed via a biopsy for further analysis. If the tissue is cancerous, further tests are necessary to determine whether or not the cancer has spread from the mouth to lymph nodes or other parts of the body.
Once oral cancer has been diagnosed, the standard treatment approach is to remove the tumor surgically, particularly if it is not yet large. Reconstructive surgery may then be required, depending on how much tissue and bone material had to be removed during surgery. Mouth surgery can cause long-term effects on speech and on the ability to chew and swallow food.
Following surgery, and especially in cases where the disease has already spread from the primary tumour (after which surgery is no longer effective at eliminating cancer), radiation treatment and chemotherapy may both be used to combat oral cancer. Common chemotherapy drugs include cetuximab. Chemotherapy drugs often cause very serious side effects, although the particular side effects depend on the particular drug or drugs used.
- Surviving Oral Cancer -
Oral cancer is easily detected, but few undergo the necessary examination, so that it is often only found in relatively late stages, when treatment is far more difficult. Overall, about 15% of people are only diagnosed with oral cancer after it has already spread to the voice box, the esophagus, or another part of the body. Otherwise, survival rates depend on where the cancer is first detected. Oral cancer which begins on the lip is most survivable, with five-year survival rates ranging from 96% when it is caught early on, to 48% when it is caught only in its final stage (after spreading throughout the body).
In general, the deeper into the oral cavity the cancer is discovered, the less effective treatment becomes. Cancer on the tongue has a five-year survival rate of 37%-71%, depending on how far it has progressed before being caught. However, the five-year survival rate for cancer beginning in the oropharynx (just behind the oral cavity) is just 44%-56%.
If you are concerned that you are at risk of oral cancer, or have symptoms of oral cancer, you should always discuss your concerns with your doctor. The key to improving the chances of successfully treating cancer is getting an early diagnosis.
- Sources and More Information -
American Cancer Society. "What are Oral Cavity and Oropharyngeal Cancers?" and "What are the Key Statistics about Oral Cavity and Oropharyngeal Cancers?"
Oral Cancer Foundation. "Oral Cancer Facts."