Oral and Lip Cancer
The Oral Cavity is made up of several parts:
- Front two thirds of the tongue
- Buccal mucosa (the lining of the inside of the cheeks)
- Floor (bottom) of the mouth under the tongue
- Hard palate (the roof of the mouth)
- Retromolar trigone (the small area behind the wisdom teeth)
The oral cavity helps you to breathe, talk, eat, chew, and swallow. Minor salivary glands located throughout the oropharynx make saliva that keeps your mouth moist and helps you digest food. And, it is composed of several types of body tissues, which are made up of several types of cells.
Oral cavity cancer starts and develops in the mouth.
Squamous Cell Carcinomas
More than 90% of oral cavity cancers are squamous cell carcinomas, also called squamous cell cancers. Squamous cells are flat, scale-like cells that normally form the lining of the mouth and throat. 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 outer layer of cells called the epithelium. This is different from invasive squamous cell carcinoma, where the cancer cells have grown into deeper layers of the mouth.
Risk factors for lip and oral cavity cancer include:
- Using tobacco products
- Heavy alcohol use
- Being exposed to natural sunlight or artificial sunlight (such as from tanning beds) over long periods of time
- Being infected with human papillomavirus (HPV)
These and other symptoms may be caused by lip and oral cavity cancer. Other conditions may cause the same symptoms. Consult a doctor if you have any of the following problems:
- A sore on the lip or in the mouth that does not heal
- A lump or thickening on the lips or gums or in the mouth
- A white or red patch on the gums, tongue, tonsils, or lining of the mouth
- Bleeding, pain, or numbness in the lip or mouth
- Change in voice
- Loose teeth or dentures that no longer fit well
- Trouble chewing or swallowing or moving the tongue or jaw
- Swelling of jaw
- Sore throat or feeling that something is caught in the throat
Lip and oral cavity cancer may not have any symptoms and is sometimes found during a regular dental exam.
If you are diagnosed with lip or oral cancer, the doctor needs to know the stage, or extent, of the disease to plan the best treatment. Staging is a careful attempt to find out whether the cancer has spread, and if so, to what parts of the body.
The most common system used to describe the extent of oral cavity cancers is the TNM System:
- T - Indicates the size of the primary tumor and which, if any, tissues of the oral cavity or oropharynx it has spread to.
- N - Describes the extent of spread to nearby lymph nodes.
- M - Indicates whether the cancer has spread to other organs of the body. (The most common site of spread is to the lungs. The next most common sites are the liver and bones.)
Numbers or letters appear after T, N, and M to provide details about each of these factors. The numbers 0 through 4 indicate increasing severity. The letter X means "cannot be assessed" because the information is not available.
Once the T, N, and M categories have been assigned, this information is combined by a process called stage grouping to assign an overall stage of 0, I, II, III, or IV. Stage IV is further divided into A, B, and C.
Stage 0: Tis, N0, M0: Carcinoma in Situ. The cancer is only growing in the epithelium, the outer layer of oral tissue (Tis). It has not yet grown into a deeper layer or spread to nearby structures, lymph nodes (N0), or distant sites (M0).
Stage I: T1, N0, M0: The tumor is two centimeters (about ¾ inch) across or smaller (T1) and has not spread to nearby structures, lymph nodes (N0), or distant sites (M0).
Stage II: T2, N0, M0: The tumor is larger than 2 cm across but smaller than 4 cm (T2) and has not spread to nearby structures, lymph nodes (N0), or distant sites (M0).
Stage III: One of the following applies:
- T3, N0, M0: The tumor is larger than three centimeters across, but it hasn't grown into nearby structures or spread to the lymph nodes (N0) or distant sites (M0)
- T1 to T3, N1, M0: The tumor is any size and hasn't grown into nearby structures (T1 to T3). It has spread to one lymph node on the same side of the head or neck, which is smaller than three centimeters across (N1). The cancer hasn't spread to distant sites (M0).
Stage IVA: One of the following applies:
- T4a, N0 or N1, M0: The tumor is growing into nearby structures (T4a). It can be any size. It has either not spread to the lymph nodes (N0) or has spread to one lymph node, on the same side of the head or neck, which is smaller than three centimeters across (N1). The cancer hasn't spread to distant sites (M0).
- T1 to T4a, N2, M0: The tumor is any size and may or may not grow into nearby structures. It has not spread to distant sites (M0). It has spread to one of the following:
- One lymph node on the same side of the head and neck that is between three and six centimeters across (N2a)
- One lymph node on the opposite side of the head and neck that is less than six centimeters across (N2b)
- Two or more lymph nodes, all of which are smaller than six centimeters across. The lymph nodes can be on any side of the neck (N2c)
Stage IVB: One of the following applies:
- T4b, any N, M0: The tumor is growing into deeper areas and/or tissues (very advanced local disease - T4b). It may (or may not) have spread to lymph nodes (any N). It has not spread to distant sites (M0).
- Any T, N3, M0: The tumor is any size and it may or may not have grown into other structures (any T). It has spread to one or more lymph nodes larger than 6 cm across (N3), but it hasn't spread to distant sites (M0).
Stage IVC: Any T, Any N, M1: The tumor is any size, and it may or may not have spread to lymph nodes. It has spread to distant sites, most commonly the lungs.
Your doctor will do a physical exam and ask you many questions. It is important to describe how you have been feeling and any changes you have noticed, such as pain, difficulty swallowing, mouth or throat sores, or changes in your voice.
Your doctor may order some of these tests:
- Endoscopy - A thin, lighted tube is inserted through the nose to look at the back of your nose and throat. This may be done at the doctor’s office, often after using numbing spray.
- Biopsy - A sample of tissue is removed to check for cancer.
- Fine needle aspiration - This is a type of biopsy done with a small needle to see if you have cancer. It is often used to assess lumps in the neck.
- Fiberoptic endoscopic evaluation of swallowing test (FEES) - A thin, lighted tube is inserted through your nose and down your throat so that the health care provider can watch how you swallow from inside.
- Biomarker testing/Molecular testing of the tumor - Your doctor may want to test your tumor for P16 or HPV. In certain kinds of head and neck cancer (oropharyngeal squamous cell carcinomas), knowing this test result will help your doctor decide on the treatment that is best for you. The tumor may also be assessed for the Epstein-Barr Virus (EBV). This can cause cancers in the nasopharynx (upper part of the throat behind the nose).
Your doctor may also use the following diagnostic tests:
- CT Scan
- PET or PET-CT Scan
- Modified barium swallow studies (a series of x-rays taken after you swallow a barium drink)
Treatment and Side Effects
Surgery is a common treatment for all stages of lip and oral cavity cancer. Surgery may include the following:
- Wide local excision - Removal of the cancer and some of the healthy tissue around it. If cancer has spread into bone, surgery may include removal of the involved bone tissue.
- Neck dissection - Removal of lymph nodes and other tissues in the neck. This is done when cancer may have spread from the lip and oral cavity.
- Plastic surgery - An operation that restores or improves the appearance of parts of the body. Dental implants, a skin graft, or other plastic surgery may be needed to repair parts of the mouth, throat, or neck after removal of large tumors.
Even if the doctor removes all the cancer that can be seen at the time of the surgery, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that are left. Treatment given after the surgery, called adjuvant therapy, lowers the risk that the cancer will come back.
The most common side effects of any neck dissection are numbness of the ear, weakness when raising the arm above the head, and weakness of the lower lip. These side effects are caused by injury during the operation to certain nerves that supply these areas.
After a selective neck dissection, weakness of the arm and lower lip usually go away after a few months. But if either nerve is removed as part of a radical neck dissection or because of involvement with tumor, the weakness will be permanent.
Cancers of the head and neck are treated by operations that remove part of the facial bone structure. The changes are visible, so they can be devastating. Recent advances in facial prostheses are now giving patients the ability to have a more normal look and also improving vocal clarity (another side effect of surgical treatments).