Oral Cancer Introduction Oral cancer is cancer that develops in any part of the oral cavity, including the mouth and lips, or the oropharynx, the part of the throat at the back of the mouth. Oral cancer is a common type of cancer, especially among men. About 6 out of every 100,000 people will develop oral cancer each year. The earlier oral cancer is detected and treated, the more likely are the chances of a successful treatment. This reference summary will help you better understand what oral cancer is and what treatment options are available. Anatomy of the Oral Cavity The oral cavity includes the lips, front two-thirds of the tongue, the gums and teeth, the buccal mucosa, the floor of the mouth under the tongue, the salivary glands, and the hard palate. The buccal mucosa is the lining inside the cheeks and lips. The hard palate is the bony top of the mouth. The salivary glands make saliva. Saliva is the watery fluid in the mouth. This fluid moistens food to help digestion. Saliva also protects the mouth against infection. There are many salivary glands but the major ones are in the floor of the mouth near the jawbone. Oropharynx The oropharynx is the middle part of the pharynx and includes the soft palate, base of the tongue and tonsils. The soft palate is the back, muscular part of the roof of the mouth. The tonsils are two small masses of tissue on either side of the throat. 1
Oral Cancer The body is made up of very small cells. Normal cells in the body grow and die in a controlled way. Sometimes cells keep dividing and growing in an uncontrolled way, causing an abnormal growth called a tumor. If the tumor does not invade nearby tissues and body parts, it is called a benign tumor, or non-cancerous growth. Benign tumors are usually not life threatening. It the tumor invades nearby tissues and body parts, it is called a malignant tumor or cancer. Cancerous cells spread to different parts of the body through blood vessels and lymph channels. Lymph is a clear fluid produced by the body that drains waste from cells. It travels through special vessels and bean-shaped structures called lymph nodes. Cancer that moves from one tissue to other body parts is known as metastatic cancer. For instance, an oral tumor may grow as big as a lime and invade nearby tissues over time. Lymph System Cancers in the body are given names, depending on where the cancer started. Cancer that begins in the oral cavity will always be called oral cancer, even if it spreads to other places. Risk Factors It is usually impossible to specify the cause of cancer in an individual patient. However, we do know what causes cancer in general. Doctors also know factors that can increase the chances of getting cancer. These are known as risk factors. Tobacco use causes most oral cancers. Smoking cigarettes, cigars, or pipes, or using smokeless tobacco causes oral cancer. The risk of oral cancer increases with the amount of time a person has used tobacco. People who are heavy drinkers are also more likely to develop oral cancer. The risk increases with the amount of alcohol that a person drinks. 2
People who use both tobacco and alcohol are at an even greater risk for developing oral cancer. Three out of 4 people with oral cancer have used tobacco, alcohol, or both. The Human Papilloma Virus, HPV for short, is a sexually transmitted virus that can cause genital warts. Some HPV viruses can infect the mouth and throat. Cancers at the base of the tongue, back of the throat, in the tonsils, or in the soft palate are linked to HPV infection. Exposure to the sun increases the risk for cancer of the lip. Using a lotion or lip balm that has sunscreen can reduce this risk. Another risk factor for oral cancer is medical history. People who have had oral cancer are at increased risk of developing another oral cancer. Diet may also increase a person s risk for oral cancer. Some studies suggest that not eating enough fruits and vegetables may increase the chance of getting oral cancer. Chewing betel nut may cause oral cancer. Betel nut is a type of palm seed wrapped with a betel leaf and sometimes mixed with spices, sweeteners, and tobacco. It is most common in Asia. Not everybody who has risk factors for oral cancer develops oral cancer. Some people who have no risk factors for oral cancer can still develop the cancer. Symptoms One common symptom of oral cancer is patches inside of your mouth or on your lips. The color of the patches determines how malignant the tumor is. White patches, called leukoplakia, are the most common. White patches sometimes become malignant. Mixed red and white patches, called erythroleukoplakia, are more likely than white patches to become malignant. Red patches, called erythroplakia, are brightly colored, smooth areas that often become malignant. 3
Common symptoms of oral cancer may also include: A sore on your lip or in your mouth that doesn t heal Bleeding in your mouth Loose teeth Difficulty or pain when swallowing Other common symptoms of oral cancer may include: Difficulty wearing dentures A lump in your neck An earache that doesn t go away Numbness of lower lip and chin There are diseases other than cancer that can cause symptoms similar to those of oral cancer. If you or your loved ones have any of these symptoms, make sure to see a doctor to find out what is causing them. Diagnosis The best way to treat oral cancer is by finding it very early. It is sometimes possible to find this type of cancer even before it causes any symptoms. If you have symptoms of oral cancer, your doctor will try to find out if oral cancer is the cause of your symptoms or if there is another cause. Your doctor will ask you about your medical history. A physical exam will be performed to check your mouth and throat for red or white patches, lumps, swelling, or other problems. You may be referred to an ear, nose, and throat specialist if your doctor cannot find the cause of your symptoms. The specialist can use a small, long-handled mirror or lighted tube to see the back of your nose, tongue, and throat. A CT scan may need to be used to check for hidden tumors. A CT scan is an x-ray machine linked to a computer. A CT scan takes a series of detailed pictures of organs inside the body. 4
An MRI is also used to make detailed pictures of areas inside your body. It uses strong magnets to create images of the inside of the body. Hidden tumors may also be found using an MRI. A biopsy may also be performed to diagnose oral cancer. A biopsy is a removal of cells or tissue for examination by a pathologist. A pathologist will examine the tissue under a microscope to look for cancer cells. A biopsy is the only sure way to know if cancer cells are present. Staging If you have oral cancer, your doctor will determine the stage of the cancer. Staging is an attempt to find out if the cancer has spread and, if so, to which parts of the body. Stages are usually described using the numbers 1 to 4; a lower number indicates an earlier stage. Staging is helpful in deciding the best course of treatment. If oral cancer has spread to nearby lymph nodes, it can spread to other areas of the body. Oral cancer can spread to farther lymph nodes, the bones, liver, lungs, and other parts of the body. An x-ray is one test that may be done to determine the stage of oral cancer. An x-ray of your entire mouth can show whether cancer has spread to the jaw. X-ray images of your chest and lungs can show whether cancer has spread to these areas. A CT scan or MRI may also be done to look for tumors in your mouth, throat, neck, lungs, or elsewhere in the body. An endoscopy may be done to check your throat, windpipe, and lungs for cancer. During this test, the doctor inserts a thin, lighted tube through your nose or mouth. A PET scan can show if the oral cancer has spread elsewhere in the body. For this test, you are injected with a small and safe amount of radioactive sugar. The PET scanner makes a picture of the places in your body where the sugar is being taken up. Cancer cells show up brighter because they use sugar faster than normal cells. 5
Treatment and Supportive Care The choice of treatment depends mainly on your general health, where in your mouth or throat the cancer began, the size of the tumor, and whether the cancer has spread. Treatment for oral cancer may involve surgery, radiation therapy, chemotherapy, targeted therapy, or some combination of these treatments. Surgery to remove the tumor in the mouth or throat is a common treatment for oral cancer. Sometimes the surgeon also removes lymph nodes in the neck, as well as other tissues. Some surgeries may result in swallowing difficulties or muscle weakness in the mouth. Radiation therapy uses high-energy rays to kill cancer cells and stop them from growing and spreading. External radiation that treats the cells comes from a machine that aims the rays at a specific area of the body. Internal radiation may also be used to treat oral cancer, although this is not as common. The radiation comes from radioactive material in seeds, wires, or tubes put directly in the mouth or throat tissue. Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy to treat oral cancer is usually given through an IV. The drugs enter the bloodstream and travel throughout the body. Target therapy uses drugs that bind to oral cancer cells and interfere with cancer cell growth and the spread of cancer. Cetuximab (Erbitux ) is the first targeted therapy approved for oral cancer. It is usually given through a vein. There also may be clinical trials available for people with oral cancer. Clinical trials test new medical approaches and treatments. Oral cancer and its treatment can lead to other health problems. It is important to have supportive care before, during, and after cancer treatment. Supportive care is treatment to control pain and other symptoms, to relieve the side effects of therapy, and to help you cope with emotions. 6
If swallowing becomes difficult, a dietitian can help you plan a diet that will meet your nutritional needs. Some people with oral cancer may need to have plastic or reconstructive surgery to rebuild the bones or tissues of the mouth. Rehabilitation may also be needed. During rehabilitation, healthcare professionals teach the patients how to train and strengthen the muscles of the affected area. This can be helpful to regain the ability to talk, eat, and chew. If you are diagnosed with oral cancer, it is important for you to attend your doctor appointments for follow-up care. Your doctor will watch for any signs of cancer that has returned. Summary Oral cancer is cancer that develops in any part of the oral cavity, including the mouth and lips, or the oropharynx, the part of the throat at the back of the mouth. Oral cancer is a common type of cancer, especially among men. About 6 out of every 100,000 people worldwide will develop oral cancer each year. Not smoking, not using tobacco products and not drinking alcohol are the single most important life style choices you can make to prevent oral cancer The earlier oral cancer is detected and treated, the more likely are the chances of a successful treatment. Treatment for oral cancer may involve surgery, radiation therapy, chemotherapy, targeted therapy, or some combination of these treatments. 7