Oral Complications of Chemotherapy and Radiation Therapy

by National Cancer Institute

Oral complications are common in patients receiving chemotherapy or undergoing radiation therapy to the head and neck.

The oral cavity is at high risk of side effects from chemotherapy and radiation therapy for a number of reasons.

Chemotherapy and radiation therapy stop the growth of rapidly dividing cells, such as cancer cells. Since normal cells in the lining of the mouth also divide rapidly, anticancer treatment can prevent cells in the mouth from reproducing, making it difficult for oral tissue to repair itself.

The mouth contains hundreds of different bacteria, some helpful and some harmful. Chemotherapy and radiation therapy can cause changes in the lining of the mouth and production of saliva and upset the healthy balance of bacteria. These changes may lead to mouth sores, infections, and tooth decay.

Wear and tear occur from normal use of the mouth, teeth, and jaws, making healing more difficult.

Preventive measures may lessen the severity of oral complications.

Oral side effects may make it difficult for a patient to receive all of his or her cancer treatment. Sometimes treatment must be stopped. Preventing and controlling oral complications will enhance both the patient's quality of life and the effectiveness of cancer therapy.

Preventing and treating oral complications of cancer therapy involve identifying the patient at risk, starting preventive measures before cancer therapy begins, and treating complications as soon as they appear.

Description and Causes

Radiation therapy and chemotherapy may cause some of the same oral side effects, including the following:

• Mucositis (an inflammation of the mucous membranes in the mouth).
• Infections in the mouth or that travel through the bloodstream, reaching and affecting cells all over the body.
• Taste changes.
• Dry mouth.
• Pain.
• Changes in dental growth and development in children.
• Malnutrition (lack of nutrients needed by the body for health, often caused by the inability to eat).
• Dehydration (lack of water needed by the body for health, often caused by the inability to drink).
• Tooth decay and gum disease.

Complications may be caused directly or indirectly by anticancer therapy.

Oral complications associated with chemotherapy and radiation therapy may be caused directly by the treatment or may result indirectly from side effects of the treatment. Radiation therapy may directly damage oral tissue, salivary glands, and bone. Areas treated may scar or waste away.

Slow healing and infection are indirect complications of cancer treatment. Both chemotherapy and radiation therapy can affect the ability of cells to reproduce, which slows the healing process in the mouth. Chemotherapy may reduce the number of white blood cells and weaken the immune system (the organs and cells that defend the body against infection and disease), making it easier for the patient to develop an infection.

Complications can be acute or chronic.

Acute complications are those that occur during therapy. Chemotherapy usually causes acute complications that heal after treatment ends.

Chronic complications are those that continue or develop months to years after therapy ends. Radiation can cause acute complications but may also cause permanent tissue damage that puts the patient at a lifelong risk of oral complications. The following chronic complications commonly continue after radiation therapy to the head and/or neck has ended:

• Dry mouth.
• Tooth decay.
• Infections.
• Taste changes.
• Problems using the mouth and jaw due to tissue and bone loss and/or the growth of benign tumors in the skin and muscle.

Invasive dental procedures can cause additional problems. The dental care of patients who have undergone radiation therapy will therefore need to be adapted to the patient's ongoing complications.

Prevention and Treatment of Oral Complications Before Chemotherapy and/or Radiation Therapy Begins

Finding and treating oral problems before anticancer therapy begins can prevent or lessen the severity of oral complications.

Oral complications in patients undergoing treatment for head and neck cancer may be reduced by aggressive prevention measures taken before treatment begins. This will get the mouth and teeth in the best possible condition to withstand treatment.

Preventive measures include the following:

Eating a well-balanced diet. Proper nutrition can help the body tolerate the stress of cancer treatment, maintain energy, fight infection, and rebuild tissue.

Learning how to care for the mouth and teeth during and after anticancer therapy. Good dental hygiene helps prevent cavities, mouth sores, and infections.

Having a complete oral health exam by a dentist familiar with the oral side effects of anticancer treatments.

The cancer care team should include the patient's dentist. It is important to choose a dentist familiar with the oral side effects of chemotherapy and/or radiation therapy. An evaluation of the patient's oral health at least a month before treatment begins usually provides enough time for the mouth to heal after dental work. The dentist will identify and treat teeth at risk for infection or decay, so the patient may avoid having invasive dental treatment during anticancer therapy. The dentist may also provide appropriate preventive care to lessen the severity of dry mouth, a common complication of radiation therapy to the head and neck.

A preventive oral health exam will check for the following:

• Mouth sores or infections.
• Tooth decay.
• Gum disease.
• Dentures that do not fit well.
• Problems moving the jaw.
• Problems with the salivary glands.

Patients undergoing high-dose chemotherapy, stem cell transplant, and/or radiation therapy need an oral care plan in place before treatment begins.

The goal of the oral care plan is to find and treat oral disease that may produce complications during treatment and to continue oral care throughout treatment and recovery. Different oral complications may occur during the different phases of transplantation. Steps can be taken ahead of time to prevent or lessen the severity of these side effects.

Ongoing oral care during radiation therapy will depend on the specific needs of the patient; the dose, locations, and duration of the radiation treatment; and the specific complications that occur.

It is important that patients who have head or neck cancer stop smoking.

Continued smoking slows recovery and increases the risk that the head or neck cancer will recur or that a second cancer will develop.

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