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.

Glossary Terms

Symptoms or signs that begin and worsen quickly; not chronic.

A noncancerous growth that does not invade nearby tissue or spread to other parts of the body.

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

Treatment with drugs that kill cancer cells.

A disease or condition that persists or progresses over a long period of time.

In medicine, a medical problem that occurs during a disease, or after a procedure or treatment. The complication may be caused by the disease, procedure, or treatment or may be unrelated to them.

A condition caused by the loss of too much water from the body. Severe diarrhea or vomiting can cause dehydration.

The complex group of organs and cells that defends the body against infections and other diseases.

Invasion and multiplication of germs in the body. Infections can occur in any part of the body and can spread throughout the body. The germs may be bacteria, viruses, yeast, or fungi. They can cause a fever and other problems, depending on where the infection occurs. When the body’s natural defense system is strong, it can often fight the germs and prevent infection. Some cancer treatments can weaken the natural defense system.

Redness, swelling, pain, and/or a feeling of heat in an area of the body. This is a protective reaction to injury, disease, or irritation of the tissues.

A medical procedure that invades (enters) the body, usually by cutting or puncturing the skin or by inserting instruments into the body.

A disorder caused by a lack of proper nutrition or an inability to absorb nutrients from food.

A complication of some cancer therapies in which the lining of the digestive system becomes inflamed. Often seen as sores in the mouth.

The moist, inner lining of some organs and body cavities (such as the nose, mouth, lungs, and stomach). Glands in the mucous membrane make mucus (a thick, slippery fluid). Also called mucosa.

A chemical compound (such as protein, fat, carbohydrate, vitamin, or mineral) contained in foods. These compounds are used by the body to function and grow.

By or having to do with the mouth.

A part of the body that performs a specific function. For example, the heart is an organ.

Energy released in the form of particle or electromagnetic waves. Common sources of radiation include radon gas, cosmic rays from outer space, medical x-rays, and energy given off by a radioisotope (unstable form of a chemical element that releases radiation as it breaks down and becomes more stable).

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

A gland in the mouth that produces saliva.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

A group or layer of cells that work together to perform a specific function.

Refers to a blood cell that does not contain hemoglobin. White blood cells include lymphocytes, neutrophils, eosinophils, macrophages, and mast cells. These cells are made by bone marrow and help the body fight infections and other diseases. Also called WBC.