Oral cancer is cancer that starts in the mouth, also called the oral cavity. The oral cavity includes the lips, the inside lining of the lips and cheeks (buccal mucosa), the teeth, the gums, the front two-thirds of the tongue, the floor of the mouth below the tongue, the bony roof of the mouth (hard palate), and the area behind the wisdom teeth (retromolar trigone).

Oropharyngeal cancer develops in the part of the throat just behind the mouth, called the oropharynx. The oropharynx begins where the oral cavity stops. It includes the base of tongue (the back third of the tongue), the soft palate, the tonsils and tonsillar pillars, and the back wall of the throat (the posterior pharyngeal wall).

The oral cavity and oropharynx assist with breathing, talking, eating, chewing, and swallowing. Minor salivary glands located throughout the oral cavity and oropharynx make saliva that keeps the mouth moist and helps digest food.

The oral cavity and oropharynx contain several types of tissue and each of these tissues contains several types of cells. Different cancers can develop from each kind of cell. The differences are important, because they influence the patient's treatment options and outlook for recovery.

Just above the oropharynx is the nasopharynx. Because cancers from this area are different from those of the oral cavity and oropharynx, they are discussed in a separate document.

Many types of tumors can develop in the oral cavity and oropharynx. Some of these tumors are benign, or noncancerous. They do not invade other tissues and do not spread to other parts of the body. Others are cancerous, which means they can penetrate into surrounding tissues and spread to other parts of the body. There are also some growths that start off harmless but can later develop into cancer. These are known as precancerous conditions.

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Benign tumors and tumor-like conditions include eosinophilic granuloma, fibroma, granular cell tumor, keratoacanthoma, leiomyoma, osteochondroma, lipoma, schwannoma, neurofibroma, papilloma, condyloma acuminatum, verruciform xanthoma, pyogenic granuloma, and rhabdomyoma, as well as odontogenic tumors. The usual treatment for these conditions is surgical removal. Recurrence is unlikely.

Leukoplakia, Erythroplakia, and Dysplasia

Leukoplakia and erythroplakia are terms that describe an abnormal area in the mouth or throat. Leukoplakia is a white area. Erythroplakia is a slightly raised, red area that bleeds easily if scraped. The seriousness of leukoplakia or erythroplakia in each person can be accurately determined only by a biopsy, a sampling of tissue for examination under the microscope. Sometimes the abnormal area can be evaluated by exfoliative cytology. In this technique, the lesion is scraped with an instrument, and the cells from the scraping can be examined under the microscope.

These white or red areas may be a cancer, or they may be a precancerous condition called dysplasia. They could also be some relatively harmless condition. There are mild, moderate, and severe forms of dysplasia, which are distinguished from one another based on how abnormal the tissue appears under the microscope. Knowing the degree of dysplasia helps predict how likely the abnormality is to progress to cancer or to go away on its own or after treatment. Often dysplasia will go away if the factor that causes it is eliminated. The most frequent causes of these conditions are smoking or chewing tobacco. Irritation from poorly fitting dentures rubbing against the tongue or inside of the cheeks can cause leukoplakia or erythroplakia. Treatment with drugs related to vitamin A (retinoids) applied to the lesions might help eliminate some areas of dysplasia or prevent others from forming.

Most of the time, leukoplakia is the result of a benign condition that is very unlikely to develop into cancer. About 25% of leukoplakias, however, are either cancerous when first found or involve precancerous changes that progress to cancer within 10 years if not properly treated. Erythroplakia is usually more serious. As many as 70% of these red lesions will be diagnosed as cancer at the time of initial biopsy or will develop into cancer.

More important is measuring the DNA content of the leukoplakia or erythroplakia cells. This is a test that can be done in many laboratories. If the DNA content is normal, the chance of cancer developing is low – although it can occur. But if the DNA content is abnormal – usually too much DNA – the chance of cancer developing is very high.

Malignant Oral Cavity and Oropharyngeal Tumors

More than 90% of cancers of the oral cavity and oropharynx are squamous cell carcinomas, also called squamous cell cancer. Squamous cells are flat, scale-like cells that normally form the lining of the oral cavity and oropharynx. Squamous cell cancer begins as a collection of abnormal squamous cells. The earliest form of squamous cell cancer is called carcinoma in situ, meaning that the cancer cells are present only in the lining layer of cells called the epithelium. Invasive squamous cell cancer means that the cancer cells have spread beyond this layer into deeper layers of the oral cavity or oropharynx.

Verrucous carcinoma is a type of squamous cell carcinoma that makes up less than 5% of all oral cavity tumors. It is a low-grade cancer that rarely metastasizes but can deeply spread into surrounding tissue. Therefore, surgical removal of the tumor with a wide margin of surrounding tissue is advised.

Minor salivary gland cancers can develop in the glands that are found throughout the mucosal lining of the oral cavity and oropharynx. There are several types of minor salivary gland cancers including adenoid cystic carcinoma, mucoepidermoid carcinoma, and polymorphous low-grade adenocarcinoma. For more information about these cancers and benign salivary gland tumors, refer to our document on salivary gland cancer.

The tonsils and base of tongue contain immune system (lymphoid) tissue that can develop into a cancer. For more information about these cancers refer to our documents on adult non-Hodgkin lymphoma, childhood non-Hodgkin lymphoma, and Hodgkin disease.

The treatment and outlook for cure (prognosis) for minor salivary gland cancers and lymphomas are different from that of squamous cell carcinoma and are not discussed in this document. The information in the rest of this document about oral cavity and oropharyngeal cancer refers only to squamous cell carcinoma.

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Doctors and scientists can't say for sure what causes each case of oral cavity and oropharyngeal cancer. But we do know many of the risk factors and how some of them cause cells to become cancerous. We know that tobacco and alcohol can damage cells in the lining of the oral cavity and oropharynx, and that cells in this layer must grow more rapidly to repair this damage. Many of the chemicals found in tobacco cause damage to DNA, which contains the cell's instructions for repair and growth.

Scientists are not sure whether alcohol directly damages DNA, but they have shown that alcohol increases penetration of many DNA-damaging chemicals into cells. This is one reason that the combination of tobacco and alcohol causes far more damage to DNA than tobacco alone. This damage can cause certain areas of DNA (for example, those in charge of starting or stopping cell growth) to malfunction. Then abnormal cells can begin to accumulate, forming a tumor. With additional damage, the cells may begin to spread into nearby tissue and spread to distant organs.

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• a sore in the mouth that does not heal (most common symptom)
• pain in the mouth that doesn't go away (also very common)
• a persistent lump or thickening in the cheek
• a persistent white or red patch on the gums, tongue, tonsil, or lining of the mouth
• a sore throat or a feeling that something is caught in the throat that doesn't go away
• difficulty chewing or swallowing
• difficulty moving the jaw or tongue
• numbness of the tongue or other area of the mouth
• swelling of the jaw that causes dentures to fit poorly or become uncomfortable
• loosening of the teeth or pain around the teeth or jaw
• voice changes
• a lump or mass in the neck
• weight loss
• persistent bad breath

Complete medical history: The first step in any medical evaluation is to gather information about symptoms, risk factors, and other medical conditions.

Physical examination: Your doctor will do a complete physical examination and look for certain abnormalities that may be caused by an oral or oropharyngeal cancer. These could be nodules on your head, face or neck, or abnormalities of nerves of the face and mouth. The doctor will feel the entire inside of your mouth with a gloved finger.

Consultation with a specialist: If there is a reason to think you might have cancer, the doctor will refer you to an oral and maxillofacial surgeon and/or an head and neck surgeon (otolaryngologist) for a complete evaluation.

Complete head and neck exam (including nasopharyngoscopy, pharyngoscopy, and laryngoscopy): In addition to a complete general physical exam, special attention to the head and neck area is important. Because the oropharynx is deep inside the neck and sometimes not easily seen, special fiberoptic scopes (flexible, lighted, narrow tubes inserted through the mouth or nose) and mirrors are used to examine these areas. Indirect pharyngoscopy and laryngoscopy is the use of small mirrors to look at the pharynx, base of tongue, and larynx. Direct laryngoscopy is done with fiberoptic scopes. Because patients with oral or oropharyngeal cancer have a higher risk for more cancers in other parts of the head and neck region, the region behind the nose, the larynx, and the lymph nodes of the neck are looked at carefully and felt for any signs of cancer.

Panendoscopy (including laryngoscopy, esophagoscopy, and possible bronchoscopy): If the odds of a head and neck cancer are high, a thorough exam is done of the oral cavity, oropharynx, larynx, esophagus, and the trachea and bronchi (breathing passageways that lead to the lungs). This examination, called a panendoscopy, is done in the operating room, with the patient under general anesthesia. With the patient asleep, the head and neck surgeon is able to thoroughly examine the oral cavity and oropharynx. This would not be possible with the patient awake because of the discomfort.

Because of the significant risk of second cancers in patients with oral or oropharyngeal cancer, the surgeon will also use scopes to look at the larynx and esophagus and possibly the windpipe (trachea) and bronchi. During this exam the surgeon will remove a sample of the tumor for examination under a microscope, if this has not already been done in the office, and make an assessment of the extent of spread (stage) of the cancer.

Types of Specimens Used for Oral Cavity and Oropharyngeal Cancer Diagnosis

A sample of tissue or cells is always needed to confirm that cancer is really present before treatment is started. Several types of samples are used, depending on the patient's individual case.

Exfoliative cytology: This technique is similar to a Pap smear. The doctor scrapes a suspicious lesion and smears the tissue he collects onto a slide. The sample is then stained with a dye so the cells can be seen under the microscope. Just like a Pap smear, if any of the cells look abnormal, then a biopsy can be done. The advantage of this technique is that it is easy and even minimally abnormal-looking lesions can be examined. This makes for an earlier diagnosis and a greater chance of cure if there is cancer. However, this method does not detect all cancers and it is sometimes not possible to distinguish between cancerous cells and abnormal but noncancerous cells (dysplasia).

Incisional biopsy: This can be done either in the doctor's office or in the operating room. Where the biopsy is performed depends on the location of the tumor and how easy it is to get a good tissue sample. If done in the doctor's office, the area around the tumor will be numbed. When an office biopsy is not possible because the tumor is deep inside the mouth or throat, the biopsy is done in the operating room with the patient under general anesthesia. The surgeon uses special instruments through an endoscope to remove small tissue samples.

Fine-needle aspiration (FNA) biopsy: If a patient has a neck mass (or lump) that can be felt, a thin needle may be placed into the mass so cells can be withdrawn to check under the microscope. FNA biopsy can be used in several different situations.

It is sometimes used as the first test for someone with a newly found neck mass. The FNA may show that the neck mass is a benign lymph node that has grown in reaction to a nearby infection, such as a sinus or tooth infection. In this case, treatment of the infection is all that is needed. The FNA may find a benign (noncancerous) fluid-filled cyst that can be cured by surgery. Even when the FNA results are benign, if the patient has symptoms suggesting cancer, more tests (such as pharyngoscopy and panendoscopy) are needed. If the FNA finds cancer, the doctor looking at the sample can usually tell what type of cancer it is. If the cancer is a lymphoma (a type of cancer that starts in the lymph nodes), or if it is a cancer that has spread to a lymph node in the neck from a source in the thyroid, lungs, or other distant organs, more tests will be done. Then specific treatment for that type of cancer will be given. If the type of cells seen is consistent with cancers that begin in the oral cavity or oropharynx, more examinations will be done to search for a source in the oral cavity and oropharynx.

FNA is often done in patients known to have oral or oropharyngeal cancer to find out whether or not the cancer has metastasized, or spread, to lymph nodes in the neck. This information will help in deciding whether a neck dissection or radiotherapy is needed.

Finally, FNA may be used in patients whose cancer has been treated by surgery and/or radiation therapy, to find out whether a new neck mass in the treated area is due to scar tissue or a cancer that has come back.

This information represents the views of the doctors and nurses serving on the American Cancer Society's Cancer Information Database Editorial Board. These views are based on their interpretation of oral cavity and oropharyngeal cancer treatment studies published in medical journals, as well as their own professional experience.

The treatment information in this document is not, however, official policy of the Society and is not intended as medical advice to replace the expertise and judgment of your cancer care team. It is intended to help you and your family make informed decisions, together with your cancer care team.

Of course, your cancer care team may have reasons for suggesting a treatment plan different from these general guidelines. Don't hesitate to ask them questions about your treatment options. In addition to the information in this document, we encourage interested patients to seek out treatment information from other reliable sources.

The treatment options for people with oral and oropharyngeal cancers are surgery, radiation therapy, and chemotherapy either alone or in combination, depending on the stage of the tumor.

After the cancer is found and staged, your doctor will discuss treatment choices with you. It is important to take time and think about all of the choices. In choosing a treatment plan, factors to consider include your overall health, the type and stage of the cancer, the chances of curing the disease, and the impact of the treatment on functions like speech, chewing, and swallowing.

It is often a good idea to seek a second opinion. A second opinion can provide more information and help you feel more confident about the treatment plan you choose