Lip cancer is a malignant tumor, or neoplasm, that originates in the surface layer cells of the epithelial tissue in the upper or lower lip.
The upper and lower lips are the well-defined red (often called vermilion) areas that surround the opening to the mouth. They contain muscles and special cells (receptors) that are sensitive to heat and cold and feeling. Largely taken for granted, the lips are important in identifying types of food to the brain and in getting food into the mouth. Lips also play a crucial role in speech.
A malignant tumor, or neoplasm, that originates in the cells of one of the lips is a cancer of the lip. Lip cancer almost always begins in the flat, or squamous, epithelial cells. Epithelial cells form coverings (tissues) for the surfaces of the body. Skin, for example, has an outer layer of epithelial tissue.
If a part of the lip is affected by cancer and must be removed by surgery, there will be significant changes in eating ability and speech function. The more lip tissue removed, the greater the disturbances to the normal patterns of talking and eating.
Nine out of ten cases of lip cancer are diagnosed in people over the age of 45. Age, or the aging process, may contribute to the way the cancer develops. As a line of cells gets older, the genetic material in a cell loses some of its ability to repair itself. When the repair system is operating normally, damage to the genetic material, or DNA, caused by ultraviolet light from the sun is quickly weeded out. When the system fails, changes in the genetic material are kept, and they multiply when a cell divides.
If the genetic material cannot repair itself, damage caused by exposure to environmental factors such as sunlight and chemicals can quickly set in motion the uncontrolled growth of cells.
The effects of factors that are known to cause lip cancer, such as smoking and exposure to sunlight, also add up as a person ages. Thus, the combination of a breakdown in the repair system in the genetic material and the considerable periods of time (decades) over which a person is exposed to cancer agents probably causes lip cancers. However, researchers are still investigating how lip cancers start.
Men are at greater risk for lip cancer than women. Depending on where they live, men are two or three times more likely to be diagnosed than women. Fair-skinned people are more likely to get lip cancer than those with dark skin. For reasons not yet understood, people in Asia have a much lower risk of lip cancer than those living on other continents. In many parts of Asia, lip cancer is extremely rare. In North America, nearly 13 out of 100, 000 men will be diagnosed with lip cancer during their lifetime. In Australia, about 13.5 men per 100, 000 will be diagnosed.
The frequency of lip cancer is often lumped together with oral cancer, although lip cancer is probably much more like skin cancer in origin. There are about 30, 000 new diagnoses of mouth and lip cancer in the United States each year.
In some places, such as South Australia, women are experiencing a striking increase in lip cancer diagnoses. There are several theories to explain the trend. Among them, perhaps fewer women regularly wear hats, which offer protection from the sun. Women might also be for-going lipstick, which serves as another barrier to sunlight.
Causes and symptoms
Exposure to sunlight and smoking, particularly pipe smoking, increases the risk of developing lip cancer. However, the way they do so is not understood. Alcohol consumption is tied to oral cancers and may contribute to lip cancer as well.
Much of the evidence about the link between time spent in the sun and lip cancer comes from a look at those who are most likely to be diagnosed. Among them are farmers, golfers, and others who spend long periods of time outdoors.
Lip cancer seems to share some properties with skin cancer in the way it originates. Yet several studies suggest that it takes more than exposure to sun to increase the risk of lip cancer. Viral infection is a risk factor, as is reduced immunity, which is a condition that may be caused by viral infection. A team of researchers in the Netherlands recently reported a link between liver transplants and a higher risk of lip and skin cancer following the transplant. The results are not unexpected. In this procedure, drugs are used to suppress, or lower, the activity of a recipient's immune system so that a donor organ will be accepted. Thus, the immunity of the organ recipient is low, and lower immunity is linked to lip cancer.
Individuals with acquired immunodeficiency syndrome (AIDS) are at a greater risk for lip cancer. People infected with herpes simplex viruses, papilloma viruses and other viruses may also be at greater risk.
Vitamin deficiency may also be a factor that contributes to lip cancer. The sorts of vitamins found in fruits and vegetables, particularly carotene, the substance the body uses to form vitamins A and C, seem to be important in preventing lip cancer.
Particular symptoms of this cancer include white spots, sores, or lumps on the lip. Pain can also be a symptom, particularly pain in a lymph node near the affected part of the lip. This is a troubling symptom, since it indicates that the cancer has metastasized (spread) beyond the lip.
Dentists frequently identify a suspicious spot, sore, or lump on the lip. A good dental exam includes an examination of the lips and the mouth. X ray and biopsy , the taking of a tissue sample for analysis, can be used to determine whether or not cancer is present.
Because spots and sores on the lips can be short-lived, people should not be alarmed by every change that appears. However, when there is a change that occurs and stays, it should be investigated. If the next scheduled dental visit is several months away, a special appointment with the dentist or a physician should be made. Dentists should tell their patients, particularly older ones, how to undertake a regular self-exam of the lips between check-ups.
A physician who specializes in oncology, the study and treatment of cancer, will probably take the lead on treatment. A surgeon will remove the cancer. Not all oncologists are surgeons, so it is likely that the team will include a medical oncologist, who coordinates treatment, as well as a surgical oncologist, who performs the surgery.
Because surgery on the lip can interfere with eating and talking, most teams include a nutritionist and a speech pathologist. Scars and alterations of facial features can produce changes in body image , and a social worker may participate in the team to help a patient cope with such changes. It is possible that a dentist or oral surgeon will also play a role. Nurses who administer chemotherapy and monitor the status of patients will be involved, as will radiation technicians and a radiation oncologist. If reconstruction of a lip is necessary because of the amount of tissue removed or the size of a scar, a plastic surgeon will be added to the team.
Clinical staging, treatments, and prognosis
The ability to see a suspicious area on the lips and to detect lip cancer early combine to form the staging process. (One inch equals 2.5 centimeters.)
- Stage I: The cancer is less than one inch in diameter and has not spread.
- Stage II: The cancer is up to approximately two inches in diameter and has not spread.
- Stage III: The cancer is either larger than two inches or has spread to a lymph node on the side of the neck that matches the primary location of the lip cancer. The lymph node is enlarged, but not much more than an inch.
- Stage IV: One or more of several things can occur. There may be a spread of cancer to the mouth or to the areas around the lip, more than one lymph node with cancer, or metastasis (spread) to other parts of the body.
The outlook for recovery from lip cancer is very good if it is diagnosed early. For stage I and stage II cancers, surgery to remove the cancer or radiation treatment of the affected area is sometimes all that is required to produce a cure. Decisions about which method to use depend on many factors, but the size of the tumor and the tolerance a patient has for radiation or chemotherapy are particularly important. The larger the tumor, the more urgent is its removal. Smaller tumors can be treated with radiation or other methods in an effort to shrink them before surgery. In some cases, surgery might be avoided. For stage III cancer with lymph node involvement, the cancerous lymph nodes are also removed.
Chemotherapy may be used at any stage, but it is particularly important for stage IV cancer. In some cases, chemotherapy is used before surgery, just as radiation is, to try to eliminate the cancer without cutting, or at least to make it smaller before it is cut out (excised). After surgery, radiation therapy and chemotherapy are both used to treat patients with stage IV lip cancer, sometimes in combination.
There are many new and promising types of treatment for lip cancer. For example, heat kills some cancer cells, and a treatment known as hyperthermia uses heat to eliminate cancer in some patients.
Because lip cancers are well-studied and often successfully treated, the best practices for dealing with the cancer, or a suspected cancer, are specific. In the case of how to extract and study tissue to determine whether a suspicious growth is malignant (biopsy), size is an extremely useful guide.
It is possible to take tissue from a suspected lip cancer for examination, or biopsy, by simply piercing and extracting tissue with a large, hollow needle. The technique is called a punch biopsy. However, the method is not recommended for any tumor that is thicker than about one-sixteenth of an inch. For thicker tumors, a tissue sample is better taken by cutting into the tumor, that is, making an incision.
The success with identifying lip cancer early and eliminating it means that it is not a big killer. Only 4 in 2.5 million people die from lip cancer each year, or about 112 individuals in the entire U.S. population. In contrast, cancers in the oral cavity, including on the tongue, cause more than 8, 000 deaths in the U.S. each year.
Alternative and complementary therapies
Because there seems to be some link between a chronic absence of vitamins A and C in the diet and lip cancer, some complementary therapies promote taking massive amounts of the vitamins, or megavitamins. The value of such therapy has not been demonstrated. In order to avoid possible side effects or harmful interactions with standard cancer treatment, patients should always notify their treatment team of any over-the-counter or herbal remedies that they are taking.
Coping with cancer treatment
The doctor and patient should discuss the need for a way to communicate if speech is impaired after surgery. A pad and pencil may be all that is needed for a short interval. If there will be a long period of speech difficulty, patients should be ready with additional means, such as TYY phone service.
A change in appearance after the removal of a lip cancer can lead to concerns about body image, and social interaction may suffer. A support group can help. Discussions with a social worker, loved ones, or other patients who have undergone similar treatment can be of major benefit.
If a significant portion of lip is removed, speech therapy may be necessary to relearn how to make certain sounds. Scars and alterations of the lips usually can be reduced or hidden entirely with the techniques available from plastic surgery, so any alteration in appearance because of lip cancer is typically transient.
Reconstruction of the lip will help with appearance, but it might not make it easier to talk, especially if muscle tissue is removed during the surgery to eliminate the cancer. In many cases, the reconstruction process actually damages more muscle and sensory tissue. New methods of reconstructive surgery are being developed to avoid such an outcome.
Appetite may be affected before, during and after treatment. Before treatment, the presence of a tumor can interfere with the tasting of food, and food might not seem as appealing as it once did. During treatment, particularly radiation treatment, the area of the lips and mouth might be sore and make eating difficult. After treatment, a loss of sensation in the part of the lip affected can reduce appetite. A nutritionist can help with supplements for those who experience significant weight loss and who do not have an appetite (anorexia ).
The Cancer Information Service at the National Institutes of Health offers information about clinical trials that are looking for volunteers. The service can be reached at <http://cancertrials.nci.nih.gov> or (800) 422-6237.
The best prevention is to stay out of the sun and avoid tobacco and alcohol. Eating plenty of fruits and vegetables is a good measure. Even though the importance of fruits and vegetables is not proven to prevent lip cancer, overall fruits and vegetables are demonstrated cancer-fighters. Any precaution that is taken against contracting human immunodeficiency virus (HIV), which causes AIDS, is also likely to reduce the chance of developing lip cancer.
Certain diseases can mimic a possible lip cancer. They must be ruled out if a suspicious spot is found. This is particularly true in areas where diseases that cause lesions, or sores, on the lips are found. One such disease is histoplasmosis capsulatum, which is caused by a fungus. It sometimes produces an ulcer, or lesion, on the lip that leads to suspicion of lip cancer.
Sometimes lip cancer cannot be cured. It may keep recurring. It may also metastasize, particularly to the lungs. But overall, lip cancer is considered highly curable. Talking openly with the physician in charge of care is important in order for the patient to understand the course of the disease and be prepared to make decisions.
See Also Oropharyngeal cancer
Brennan, P., et al. "Secondary Primary Neoplasms Following Non-Hodgkin's Lymphoma in New South Wales, Australia." British Journal of Cancer 82 (April 2000):1344-7.
Haagsma, E.B., et al. "Increased Cancer Risk After Liver Transplantation: a Population-based Study." Journal of Hepatology 34 (January 2001): 84-91.
Diane M. Calabrese
QUESTIONS TO ASK THE DOCTOR
- Is this cancer curable?
- What is the stage of the cancer?
- What is the likelihood the cancer will recur?
- Is there a clinical trial in which I should participate?
—A procedure in which a tissue sample is taken from the body for examination.
—The collection of cells that form coverings for the surfaces of the body.
—Ability to resist the effects of agents, such as bacteria and viruses, that cause disease.
—A concentration of lymphatic tissue and part of the lymphatic system that collects fluid from around the cells and returns it to the blood vessels, and helps with the immune response.
—Flat epithelial cells, which usually make up the outer layer of epithelial tissue, the layer farthest away from the surface the epithelium covers.