Effect of Chemotherapy and Radiation Therapy on Nutrition

by National Cancer Institute

(Page 2 of 8)

Effect of Chemotherapy on Nutrition

Chemotherapy may affect the whole body.

Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. Because chemotherapy targets rapidly dividing cells, healthy cells that normally grow and divide rapidly may also be affected by the cancer treatments. These include cells in the mouth and digestive tract.

Nutrition-related side effects may occur during chemotherapy.

Side effects that interfere with eating and digestion may occur during chemotherapy. The following side effects are common:

• Anorexia.
• Nausea.
• Vomiting.
• Diarrhea or constipation.
• Inflammation and sores in the mouth.
• Changes in the way food tastes.
• Infections.

Nutrition therapy can treat the nutrition-related side effects of chemotherapy.

The side effects of chemotherapy may make it difficult for a patient to obtain the nutrients needed to regain healthy blood counts between chemotherapy treatments. Nutrition therapy can treat these side effects and help chemotherapy patients get the nutrients they need to tolerate and recover from treatment, prevent weight loss, and maintain general health. Nutrition therapy may include the following:

• Supplements high in calories and protein.
• Enteral nutrition (tube feedings).

Effect of Radiation Therapy on Nutrition

Radiation therapy can affect healthy cells in the treatment area.

Radiation therapy is a cancer treatment that uses high energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer.

Healthy cells that are near the cancer may be affected by the radiation treatments, and side effects may occur. The side effects depend mostly on the radiation dose and the part of the body that is treated.

Nutrition-related side effects may occur during radiation therapy.

Radiation therapy to any part of the digestive system is likely to cause nutrition-related side effects. The following side effects may occur:

Radiation therapy to the head and neck may cause anorexia, taste changes, dry mouth, inflammation of the mouth and gums, swallowing problems, jaw spasms, cavities, or infection.

Radiation therapy to the chest may cause infection in the esophagus, swallowing problems, esophageal reflux (a backwards flow of the stomach contents into the esophagus), nausea, or vomiting.

Radiation therapy to the abdomen or pelvis may cause diarrhea, nausea and vomiting, inflammation of the intestine or rectum, and fistula (holes) in the stomach or intestines. Long-term effects can include narrowing of the intestine, chronic inflamed intestines, poor absorption, or blockage in the stomach or intestine.

Radiation therapy may also cause tiredness, which can lead to a decrease in appetite and a reduced desire to eat.

Nutrition therapy can treat the nutrition-related side effects of radiation therapy.

Nutrition therapy during radiation treatment can provide the patient with enough protein and calories to tolerate the treatment, prevent weight loss, and maintain general health. Nutrition therapy may include the following:

• Nutritional supplement drinks between meals.
• Enteral nutrition (tube feedings).
• Other changes in the diet, such as eating small meals throughout the day and choosing certain kinds of foods.

Effect of Immunotherapy on Nutrition

Nutrition-related side effects may occur during immunotherapy.

Immunotherapy is treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called biologic therapy or biotherapy.

The following nutrition-related side effects are common during immunotherapy:

• Fever.
• Nausea.
• Vomiting.
• Diarrhea.
• Anorexia.
• Tiredness.

Nutrition therapy can treat the nutrition-related side effects of immunotherapy.

If the side effects of immunotherapy are not treated, weight loss and malnutrition may occur. These conditions can cause complications during recovery, such as poor healing or infection. Nutrition therapy can treat side effects from immunotherapy and help patients get the nutrients they need to tolerate treatment, prevent weight loss, and maintain general health.

Effect of Bone Marrow and Stem Cell Transplantation on Nutrition

Bone marrow and stem cell transplant patients have special nutritional needs.

Bone marrow and stem cell transplantation are methods of replacing blood-forming cells destroyed by cancer treatment with high doses of chemotherapy or radiation therapy. Stem cells (immature blood cells) are removed from the bone marrow of the patient or a donor and are frozen for storage. After the chemotherapy and radiation therapy are completed, the stored stem cells are thawed and given back to the patient through an infusion. Over a short time, these reinfused stem cells grow into (and restore) the body's blood cells.

Chemotherapy, radiation therapy, and medications used in the transplant process may cause side effects that prevent a patient from eating and digesting food as usual. These side effects include the following:

• Taste changes.
• Dry mouth.
• Thick saliva.
• Mouth and throat sores.
• Nausea and vomiting.
• Diarrhea.
• Constipation.
• Lack of appetite.
• Weight gain.

Transplant patients also have a very high risk of infection. The high doses of chemotherapy and radiation therapy reduce the number of white blood cells, the cells that fight infection. Cancer patients should be especially careful to avoid infections and food-borne illnesses. Patients are advised to avoid eating certain foods that may carry harmful bacteria.

Nutrition therapy can treat the nutrition-related side effects of bone marrow and stem cell transplantation.

Patients undergoing the transplant process need adequate protein and calories to tolerate and recover from the treatment, prevent weight loss, fight infection, and maintain general health. Nutrition therapy is also designed to avoid possible infection from bacteria in food. Nutrition therapy during the transplant process may include the following:

• A diet of only cooked and processed foods, avoiding raw vegetables and fresh fruit.
• Instruction on safe food handling.
• Specific diet guidelines based on the type of transplant and the cancer site.
• Parenteral nutrition (feeding through the bloodstream) during the first few weeks after the transplant is complete, to ensure the patient gets the calories, protein, vitamins, minerals and fluids needed for good health.

About the Author

www.nci.nih.gov
The National Cancer Institute's research programs are extensive and contain many innovative initiatives. I invite you to explore our Web site to find out more about the exciting work being conducted here at NCI and by NCI-supported scientists throughout the country.