Mouth and Throat Problems and Cancer Treatment

Cancer treatments may cause mouth, throat, and dental problems. Radiation therapy to the head and neck may harm the salivary glands and tissues in your mouth, and may make it hard to chew and swallow safely. Some types of chemotherapy and immunotherapy can also harm cells in your mouth, throat, and lips. Drugs used to treat cancer and certain bone problems may cause oral problems too.

Mouth and throat problems may include:

• changes in taste (dysgeusia) or smell
• dry mouth (xerostomia)
• infections and mouth sores
• pain or swelling in your mouth (oral mucositis)
• sensitivity to hot or cold foods
• swallowing problems (dysphagia)
• tooth decay (cavities)

Mouth problems are more serious if they interfere with eating and drinking, because they can lead to dehydration and malnutrition.

• Call 911 or go to an emergency department if you cannot swallow your own saliva, or your mouth or throat is swelling enough to make breathing noisy or hard. Go too if a fever of 100.4–100.5 degrees F (38 degrees C) or higher turns up while you are on chemotherapy: CDC calls that a medical emergency, because it may be the first sign of a serious infection at a time when your counts are low.
• Call your care team the same day if soreness in your mouth, lips, or throat is bad enough that you cannot eat, drink, or sleep.
• Call your care team within a day or two if new white patches or ulcers appear, your gums bleed when you brush, or swallowing has quietly become harder than it was last week.

That range is not a disagreement about your body: sources word the same temperature slightly differently, so use the number your own team gave you.

Your doctor or nurse may advise you to take these and other steps:

• Get a dental check-up before starting treatment. Visit your dentist for a cleaning and check-up, tell them about your cancer treatment, and try to complete any dental work before treatment starts.
• Check and clean your mouth daily. Check your mouth every day for sores or white spots, and tell your doctor or nurse as soon as you notice any changes. Rinse throughout the day with a solution of warm water, baking soda, and salt—ask your nurse to write down the recipe recommended for you. Gently brush your teeth, gums, and tongue after each meal and before bed using a very soft toothbrush or cotton swabs. If you are at risk of bleeding, ask whether you should floss.

Your healthcare team may suggest these steps:

• For a sore mouth or throat: Choose foods that are soft, wet, and easy to swallow, and soften dry foods with gravy, sauce, or other liquids. Blend foods or make milkshakes to make swallowing easier. Ask about pain medicine, such as lozenges or sprays that numb your mouth. Avoid foods that are crunchy, salty, spicy, or sugary, and avoid alcohol. Don't smoke or use tobacco.
• For a dry mouth: Drink plenty of liquids, because a dry mouth can raise the risk of tooth decay and mouth infections. Sip water often, suck on ice chips or sugar-free hard candy, have frozen desserts, or chew sugar-free gum. Use a lip balm, and ask about saliva substitutes that can coat and moisten your mouth. Acupuncture may also help with dry mouth.
• For taste changes: Food may taste different or bland. It may help to try different foods to find ones that taste best, and cold foods may help. If red meat tastes strange, try other high-protein foods like chicken, eggs, fish, or beans. If foods taste metallic, switch to plastic utensils and non-metal dishes. Marinating foods or adding spices may improve flavor.

• National Cancer Institute — Mouth and Throat Problems and Cancer Treatment
• CDC — Watch Out for Fever (Preventing Infections in People With Cancer)