Mucositis involves the inflammation of the lining of the mouth and digestive tract, and frequently occurs in cancer patients after chemotherapy and radiation therapy. The cheek, gums, soft plate, oropharynx, top and
sides of tongue, and floor of the mouth may be affected, as well as the esophagus and rectal areas. Along with redness and swelling, patients typically experience a strong, burning pain.
Although there are factors that increase the likelihood and severity of mucositis, there is no reliable manner to predict who will be affected. Not only is mucositis more common in elderly patients, the degree of breakdown is often more debilitating. The severity of mucositis tends to be increased if a patient exercises poor oral hygiene or has a compromised nutritional status. A preexisting infection or irritation to the mucous membrane may also result in a more severe case of mucositis.
Causes
The precise mechanism by which cancer treatment induces mucositis is not clear, but it is believed to damage the rapidly dividing epithelial cells in the mucous membranes. This damage leads to inflammation and swelling, and then actual breakdown of the mucosa, the lining of the mouth and digestive tract. Another theory is that the body's natural defenses are weakened. For example, the immunoglobulin IgA is normally found in saliva. In patients who developed mucositis after undergoing cancer treatment with methotrexate, IgA levels in saliva were decreased.
The types of drug used to treat cancer and the schedule by which they are given influence the risk of developing mucositis. Doxorubicin and methotrexate, for example, frequently cause mucositis. The chemotherapy agent fluorouracil does not usually severely affect the mucous membranes when administered in small doses over continuous intravenous (IV) infusion. When the schedule is adjusted so that a higher dose is given over a shorter period of time (typically over five days), fluorouracil can cause very severe, painful, dose-limiting cases of mucositis. Patients undergoing treatment with high-dose chemotherapy and bone marrow rescue usually develop mucositis.
In addition, mucositis also tends to develop in radiation therapy administered to the oral cavity, or in dosages that exceed 180 cGy per day over a five-day period. Combination therapy, either multiple chemotherapy agents or chemotherapy and radiation therapy to the oral cavity, can increase the incidence of mucositis.
Treatments
Because there is no real cure for mucositis, treatment is aimed at prevention and management of symptoms. Mucositis typically resolves a few weeks after treatment as the cells regenerate, and treatment cessation is only occasionally required. In some cases, drug therapy will be altered so that a less toxic agent is given.
Patients at risk for mucositis should be meticulous about their oral hygiene, brushing frequently with a soft toothbrush and flossing carefully with unwaxed dental floss. If bleeding of the gums develops, patients should replace their toothbrushes with soft toothettes or gauze. Dentures should also be cleaned regularly. Patients should be well-hydrated, drinking fluids frequently and rinsing the mouth several times a day. Mouthwashes that contain alcohol or hydrogen peroxide should be avoided as they may dry out the mouth and increase pain. Lips should also be kept moist. Physical irritation to the mouth should be avoided. If time permits, dental problems, such as cavities or ill-fitting dentures, should be resolved with a dentist prior to beginning cancer treatment. Patients are generally more comfortable eating mild, medium-temperature foods. Spicy, acidic, very hot or very cold foods can irritate the mucosa. Tobacco and alcohol should also be avoided.
Hospital personnel and the patients themselves should inspect the mouth frequently to look for signs and symptoms of mucositis. Evidence of mucositis (inflammation, white or yellow shiny mucous membranes developing into red, raw, painful membranes) may be present as early as four days after chemotherapy administration.
Sodium bicarbonate mouth rinses are sometimes used to decrease the amount of oral flora and promote comfort, though there is no scientific evidence that this is beneficial. Typically, patients will rinse every few hours with a solution containing 1/2 teaspoon (tsp) salt and 1/2 tsp baking soda in one cup of water.
Pain relief is often required in patients with mucositis. In some cases, rinsing with a mixture of maalox, xylocaine, and diphenhydramine hydrochloride relieves pain. However, because of xylocaine's numbing effects, taste sensation may be altered. Worse, it may reduce the body's natural gag reflex, possibly causing problems with swallowing. Coating agents such as kaopectate and aluminum hydroxide gel may also help relieve symptoms. Rinsing with benzydamine has also shown promise, not only in managing pain, but also in preventing the development of mucositis. More severe pain may require liquid tylenol with codeine, or even intravenous opioid drugs. Patients with severe pain may not be able to eat, and may also require nutritional supplements through an I.V. (intravenous line).
Alternative and complementary therapies
A treatment called cryotherapy has shown promise in patients being treated with fluorouracil administered in the aforementioned five-day, high-dose schedule. Patients continuously swish ice chips in their mouth during the thirty-minute infusion of the drug, causing the
blood vessels to constrict, thereby reducing the drug's ability to affect the oral mucosa.
Chamomile and allopurinol mouthwashes have been tried in the past to manage mucositis, but studies have found them to be ineffective. Biologic response modifiers are being evaluated to determine their possible role in managing mucositis. Recent studies using topical antimicrobial lozenges have shown promise as well, but more research is needed.
Resources
BOOKS
Abeloff, M., et al., eds. "Oral Complications." In Clinical Oncology, 2nd ed. New York, NY: Churchill Livingstone Publishers, 2000.
Varricchio, C., ed. "Mucositis." In A Cancer Source Book for Nurses. Atlanta: Jones and Bartlett Publishers, 1997, 161-73.
PERIODICALS
Balducci, L., and M. Corcoran. Hematology/Oncology Clinics of North America (February 2000): 193-203.
Epstein, J., and A. Chow. Infectious Disease Clinics of North America (December 1999): 901-18.
Tamara Brown, R.N.
Combination therapy
—Treatment involving multiple drugs or treatment methods.
