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UC Davis Comprehensive Cancer Center

UC Davis Comprehensive Cancer Center

Side effects of cancer treatment

Side effects occur when healthy cells are hurt. Different chemotherapy and radiation treatments cause different side effects. Side effects may happen right away, a week to 10 days later, or even months to years later.

In general, the side effects from chemotherapy depend on the type and dose of chemotherapy that is given. Side effects of radiation depend on which part of the body is treated with the radiation therapy. For example, if the hips receive radiation, only the skin, bone marrow and hipbone may be affected. Your doctor or nurse will talk with you about the side effects your child may experience.

Some of the most common side effects of cancer treatment are described below. Things that you and your child can do to prevent, watch for and treat the common side effects are discussed.

Low blood counts
Low white blood cell count (neutropenia)
Signs of infection
Taking your child's temperature
Low red blood cell count (anemia)
Blood transfusions
Low platelet count (thrombocytopenia)
Nose bleed
How to prevent bleeding
Nausea, vomiting, and diarrhea
Increasing fluid and food intake at home
Weight gain or loss
Mouth care
Use of pain medicines
Helping your child be more comfortable
Hair loss (alopecia)
Late effects of cancer treatment

Low blood counts

The bone marrow is the spongy part of the bones of the body. The bone marrow is the “factory” where blood cells are made. When some types of chemotherapy are given or radiation is given to the bones, this factory slows down the making of blood cells.

Three types of cells are found in the marrow and the blood: white blood cells, red blood cells and platelets. Children who receive cancer treatment commonly have low counts of these blood cells. The blood counts usually drop one week to 10 days after certain treatments are given and come back up in three to four weeks. The lowest level the blood counts reach is called the nadir. Your child's blood count may be checked often around the expected time of the nadir.

Low white blood cell count (neutropenia)

White blood cells fight infection. A normal white blood cell count is between 5,000 and 10,000 cells. The numbers on your blood count sheet may be written as 5.0 for a count of 5,000. When the white blood cell count drops below 1,000 cells (less than 1.0), the risk of infection increases. In some cases, your child may be given a medicine to help increase the number of white blood cells in the bone marrow.


Different types of white blood cells have different jobs. The differential is the breakdown of the different types of white blood cells in your child's blood count.

  • Neutrophils help to fight bacterial infections.
  • Lymphocytes make antibodies.
  • Monocytes help to fight infection by killing and removing bacteria.
  • Basophils and eosinophils respond during an allergic reaction.

You will hear the term "ANC," which stands for absolute neutrophil count. The ANC is the total number of neutrophils in your child's white blood cell count. The lower the ANC, the higher the risk of infection. When the ANC drops below 500, the risk of infection is high.

You can use a formula to find out your child's ANC.
ANC = (% segs + % bands ) x WBC

Look at your child's differential. Add the percentage of segs and bands together. Segs, bands, polys or PMNs are neutrophils. Together they make up the neutrophil count. Multiply the neutrophil count by the white blood cell count (WBC).


WBC = 10,000      % segs = 20 % bands = 1
ANC = (% segs + % bands) x WBC
ANC = (20% + 1%) x 10,000
ANC = (0.21 x 10,000)
ANC = 2,100

On most blood count reports, you will see the ANC already calculated for you. You can also ask your doctor or nurse to tell you the ANC.

Signs of infection

Call your doctor or nurse if you notice any signs of infection. If your child has a fever or pain (such as an earache, sore throat, headache, or pain with urination or having a stool), your child may have an infection. If your child has a central venous access device (central line or port), check for redness, swelling, pain or pus at the site. If you see any of these signs, call your doctor right away.

Also see these GREAT information fact sheets:


A fever may be a sign of a serious infection. If your child has a fever, call your doctor right away. Children who receive cancer treatment are at high risk for getting a serious infection in the blood. If this happens and your child does not receive medical care right away, your child could get very sick and die. Any time your child has chills and does not look well, call your doctor or nurse right away. Do not wait for the clinic to open.


Your child has a fever if his or her oral temperature reaches 101.4° or higher at any point during the day or night or if the temperature hits 100.3° or more than three times during any 24-hour period.

Taking your child's temperature

You do not need to take your child's temperature every day. Take the temperature if your child feels warm to touch or does not feel or look well. Take the temperature by mouth, in the ear using a special thermometer, or under the arm. Do not take a rectal temperature as this could cause bleeding or an infection. Make sure that you have a thermometer at home that works and that you know how to use it.

Also see these GREAT information fact sheets:

Low red blood cell count (anemia)

Red blood cells carry oxygen throughout the body. Oxygen enters the lungs with each breath and attaches, or "binds," to hemoglobin in the red blood cells. Hemoglobin carries the oxygen to all the organs and tissues in the body. Two laboratory tests are done to measure the number and function of red blood cells: a hemoglobin test and a hematocrit test.

  • Hemoglobin tests show how much oxygen the red blood cells are able to carry. A normal hemoglobin is between 12 and 16 grams. (There are some exceptions.)
  • Hematocrit tests show the percentage of red blood cells in the blood.
Signs of a low red blood cell count

When the hemoglobin count is low, less oxygen gets to organs and tissues throughout the body. A person with low hemoglobin may feel tired and short of breath. Other signs of low hemoglobin include having a headache, a fast heart rate, pale skin or gums, or dizziness.


If your child's hemoglobin is less than 7 grams, a blood transfusion may be given.

Blood transfusions

If your child needs a blood transfusion, the blood given will match your child's blood type. The blood will be given over several hours into a vein, through a central venous catheter, or through an IV in the arm. Your child will be checked during the transfusion for signs of a reaction.

The most common concern about blood transfusions is related to the HIV/AIDS and hepatitis viruses. The risk of getting AIDS from a blood transfusion today is very small: less than one chance in 676,000. The American Red Cross and other blood bank centers provide the blood for transfusions. All donor blood is tested for viruses, including HIV and hepatitis. Blood that tests positive for any disease is thrown away. Directed donation (blood donated by a family member or friend) may also be available. Research studies have shown that directed donation does not increase the safety of the blood. However, giving blood is a way that friends and family can feel like they are helping. For more information about directed donation, ask your doctor or nurse. Also see GREAT information fact sheet: Receiving a blood transfusion

Low platelet count (thrombocytopenia)

Platelets help stop bleeding in the body by forming clots. A normal platelet count is between 150,000 and 300,000 cells. When the platelet count is low, your child is at risk for bleeding.

Signs of a low platelet count

If your child has a low platelet count, you may see any of the following signs:

  • Bruising or petecchiae (small, red, pinpoint freckles on the skin).
  • Bleeding from the nose, gums or central venous access device that doesn't stop when pressure is applied to the area for 5 to 10 minutes.
  • Black stools or vomit may mean blood is in the stomach or bowel.


If your child's platelet count is less than 20,000, a platelet transfusion may be given.
If your child's platelet count is less than 50,000, he or she should not play contact sports such as football and rugby.
Use a soft toothbrush when brushing teeth to prevent bleeding of the gums. Also see GREAT information fact sheet: Mouth care.


If your child has bleeding from the nose, apply pressure to the soft part of the nose, just below the bridge. Pinch the area with your thumb and finger. Hold the pressure for 10 minutes. If the bleeding does not stop, call your doctor.

How to prevent bleeding

Putting anything in the rectum can cause bleeding or an infection. Do not give your child an enema, a suppository (medicine put into the rectum), or use a rectal thermometer to take a temperature. Do not give your child aspirin or ibuprofen (Motrin, Advil and Pediaprofen) unless you are told to do so by your doctor. These medicines cause the platelets to not work well. Some over-the-counter medicines contain aspirin (salicylate) or ibuprofen. Read the labels and check with your doctor before giving your child any over-the-counter medicines.


Many children with cancer have fatigue during and off treatment. Children may describe fatigue as feeling tired, weak or sad. Many things can cause fatigue:

  • Cancer treatment (surgery, chemotherapy, or radiation)
  • Low blood counts
  • Poor nutrition
  • Fever
  • Pain
  • Changes or decrease in sleep
  • Worry
  • Trying to do too much
Managing fatigue

Tell your doctor or nurse if your child has fatigue. You can do many things to help your child fight fatigue.
If the red blood cell count is low, your child may need blood transfusion.
If your child's diet is poor, offer healthy foods every two to three hours, while he or she is awake. Try to make each snack as nutritious as possible. For ideas, ask to speak to a dietitian.

Other ways to manage fatigue include:

  • Avoiding caffeine
  • Finding ways to decrease pain
  • Taking frequent naps
  • Trying to stick to a regular bedtime routine
  • Getting eight hours of sleep each night
  • Trying to have some physical activity every day
  • Asking your doctor about working with a physical therapist to design an exercise program to increase your child's strength and endurance
  • Sending your child to school for half the day instead of all day

Also see GREAT information fact sheet: Stay active and feel better

Nausea and vomiting

Chemotherapy and radiation therapy can cause nausea, vomiting and diarrhea. Any of these symptoms can place your child at risk for dehydration (loss of fluids in the body).

Nausea and vomiting

Chemotherapy and radiation therapy to the head, neck or stomach can cause nausea and vomiting. These treatments can irritate the stomach lining or trigger the nausea and vomiting center in the brain. Medicines to help decrease nausea and vomiting are usually given before chemotherapy or radiation. Some chemotherapy medicines cause more vomiting than others. The type and amount of anti-nausea medicine will be based on your child's treatment plan and reaction to the treatment.

Decreasing nausea and vomiting

Some ways to help decrease nausea and vomiting include:

  • Eating small meals or snacks
  • Eating foods that are easy to digest (crackers, rice, jello)
  • Taking sips of cool, clear liquids
  • Not eating fried, spicy or very rich foods
  • Eating food in a room that is free from cooking or other smells
  • Rinsing the mouth with water after vomiting


If your child has diarrhea (frequent, liquid stools), keep track of the color, amount, and frequency (number of times in 24 hours your child has diarrhea). Some ways to help decrease diarrhea include:

  • Eating a soft, bland diet (crackers, soup, rice)
  • Eating small amounts of food more often, instead of large meals
  • Not eating spicy, fried or fatty foods
  • Not drinking fruit juices, milk or milk products, such as ice cream or cheese
  • Not eating food high in fiber (fruits, vegetables, salad)
  • Eating food with potassium (tomatoes, papaya, butternut squash)
  • Limiting high-sugar food (juices, candies).

Also see GREAT information fact sheet: What to do when you have diarrhea


Fever, vomiting and diarrhea can cause dehydration, especially if your child cannot drink to replace the fluid that is lost. If your child has dry skin or a dry mouth, does not have tears when crying, or has small amounts of dark-colored urine, then your child may be dehydrated. If your child wears diapers, count the hours between wet diapers. Call your doctor if your child has any of the signs of dehydration (dry mouth, dry diapers, no tears).

Increasing fluid and food intake at home

If your child has vomiting, or diarrhea, have your child drink a small amount of fluid at least every 30 minutes. Give your child foods that are easy to digest like crackers, rice, toast or soup. Offer your child cold foods that do not have strong odors. Your doctor may also prescribe medicines to decrease vomiting and diarrhea.


Vincristine and other medicines, like pain medicines, can make your child constipated (have hard, less frequent stools). To help prevent constipation, encourage your child to drink water several times each day.

If your child is not able to drink a lot of fluid, try foods that are high in water (lettuce, fruits) to help decrease constipation. Also give your child foods that are high in fiber (fruit, vegetables, salad and whole grains). When starting a high-fiber diet, do it slowly (add 5 more grams of fiber each day). A fiber supplement may also help. Your doctor may give you a medicine to make the stools softer. Do not use enemas or suppositories without talking with your doctor.

Weight gain or loss

Weight gain from steroids

Steriods (prednisone, decadron) may cause your child to gain weight. Steroids can cause an increase in appetite and a buildup of fluid (retention). Your child may gain weight in the face and stomach. Your child will be hungry and need to eat often. Give your child healthy snacks several times a day. Try to limit the amount of salty foods that your child eats. Salt causes fluid retention. Your child will lose weight after the steroids are stopped.

Weight loss

Many children lose weight during chemotherapy or radiation treatments. Your health-care team will closely watch your child's weight. If your child cannot eat enough food to grow and stay healthy, your doctor will talk with you about giving nutrition through a tube or IV. Special formula can be given through a tube that goes through the nose into the stomach (nasogastric or "NG" tube). If your child has vomiting and cannot take food into the stomach, a special formula can be given through an IV. The formula is called total parenteral nutrition or TPN.

Suggestions to help your child maintain or gain weight include:

  • Keep healthy foods that your child likes on hand.
  • Give small snacks or meals every two hours during the day.
  • Try to add food that is high in calories, for example, you can add ice cream to a milk shake or peanut butter to toast.
  • Try not to offer a lot of fluids during meals, as this will make your child feel fuller quicker.
  • Cook foods with strong flavors that may stimulate the appetite.
  • Let your child help cook food.
  • Activity before meals may increase appetite.
  • Take advantage of the times that your child wants to eat. Always have food that you child can get easily.

Also see these GREAT information fact sheets:

Mouth care

Cells in the mouth can be affected by chemotherapy and radiation therapy to the head and neck. Keeping the mouth and teeth as clean as possible is important. Your child will feel more comfortable and you can help prevent an infection from growing in the mouth.

Caring for your child's mouth

Have your child brush his or her teeth with a soft toothbrush after each meal and before bed. Rinse the mouth with water after brushing. Do not use mouthwashes that contain alcohol. Alcohol dries out the mouth. If a dry mouth is a problem, have your child suck on hard, sugar-free candy. Also see GREAT information fact sheet: Mouth care

Caring for mouth sores

Some chemotherapy medicines and radiation therapy to the head and neck can cause mouth sores. The inside of the mouth and the tongue may be red. You may see white plaques (small raised areas) in the mouth and on the tongue. These plaques are from a fungal infection known as thrush.

If mouth sores are a problem, give your child fluids. Have your child drink the fluids with a straw. Avoid hot, spicy, or acidic foods. Give your child foods that are cold or at room temperature. Try soft or pureed (beaten or blended) foods. Avoid dry or coarse foods. Cut food into small pieces.

Rinse the mouth with water at least four times each day. Do not use mouthwash that contains alcohol.

Your doctor may give your child a medicine to treat a thrush infection. If the mouth sores are painful, your doctor will give your child a pain medicine.

Call your doctor if your child cannot drink fluids, swallow his or her own saliva (spit), or if the medicine does not help take away the pain.


Keep mouth clean, brush with soft toothbrush or toothette after meals and before bed.
Rinse mouth with mouthwash (check with nurse for types, avoid any with alcohol).
Call doctor or nurse if your child has any mouth sores; use prescribed medication to relieve pain.


Pain in children with cancer can be from many causes. Cancer cells in the blood or solid tumors in the body can cause bone or tissue pain. Some side effects of cancer treatment, such as mouth or skin sores, can be painful. Tests, like bone marrow aspirates and lumbar punctures, can be painful as well.

Telling the doctors and nurses if your child has pain is very important. Your health-care team will work to find out what is causing your child's pain. They will work with you to make a plan to decrease the pain as much as possible. Also see GREAT information fact sheet: What you can do to help your child in pain

Children of different ages understand and respond to pain differently. Here is some information to help you understand pain in children and know if your child is having pain:

How children understand and respond to pain as they grow

Understanding and response to pain

0-3 months

Does not seem to understand pain.
Memory for pain is likely, but not proved.
May show pain by kicking or crying.

3 – 6 months

Sadness and anger are a part of pain response.

6 – 18 months

Memory for pain exists.
Child is fearful of painful situations.
Uses words like owie, ouchie, or boo-boo to describe pain.

18 – 24 months

Uses the word hurt to describe pain.
Tries to avoid situations or objects that caused pain in the past.
Will seek hugs, kisses and medicine to deal with pain.

2 – 3 years

Can describe pain and explain what caused the pain.

3 – 5 years

Can describe the level of pain (no pain, a little pain, lots of pain).
Will use distraction and play to relieve pain.

5 – 7 years Can more clearly describe levels of pain.
Can use coping techniques to distract self from pain.
Uses positive self-statements.
7 – 10 years Can explain why a pain hurts.
11 years and older Can explain the value of pain.


Use of pain medicines

Always talk with your doctor or nurse before giving your child pain medicine at home. If your child has pain, giving your child the pain medicine your health-care team prescribes is safe. Some parents worry that taking pain medicine, such as morphine, can lead to addiction. However, fewer than 1 percent of people who take pain medicines become addicted. The type and amount of pain medicine and how it is given will depend on the type of pain, weight of your child, and whether or not your child can take medicine by mouth.

Helping your child be more comfortable

Parents usually know how to make their child more comfortable. As parents, you know your child the best. Tell the members of the health-care team if you think your child has pain and what has helped to make the pain better in the past.

Some ways that you can help your child be more comfortable include distraction and visual imagery. Distraction is a way to help your child think or focus on something fun or relaxing. Watching a movie and listening to music are examples of distraction. Taking deep breaths helps the body to relax and may also serve as a distraction. Visual imagery is when a person pictures being in a safe, relaxing or fun place. Using any of these methods may help your child to feel more relaxed and have less pain. A member of your health-care team will talk with you about ways to help your child be more comfortable. Also see GREAT information fact sheet: Comfort items

Hair loss (alopecia)

Some kinds of chemotherapy may cause hair loss or thinning of the hair. Radiation to the head can cause this as well. Hair loss may start seven to 10 days after the treatment is given. In some cases, all the hair falls out. Nothing can be done to prevent hair from falling out. Some children and parents prefer to cut the hair as short as possible when the hair starts to fall out. Others prefer to shave the head rather than have the hair fall out slowly. Many children wear hats or scarves and some buy a wig to wear until the hair grows back. Your social worker or child life specialist can help you order a wig or hair accessory. Also see GREAT information fact sheet: Helping your child/teen cope with body changes

Hair will usually grow back when the cancer treatments become milder or end. Your child's hair may grow back a slightly different color or texture (curlier, thicker or thinner) than before the cancer treatment. For some children who have radiation to the head, the hair may not grow back at the radiation site, especially if high doses of radiation are given.

Late effects of cancer treatment

Cancer treatment can cause side effects that happen years after treatment has ended. These effects include damage to the kidneys, liver, lungs, heart, brain and reproductive organs. In a few cases, treatment can cause a second cancer later on. The risk of late effects depends on the type and amount of treatment that your child receives. Your child will need follow-up care from a cancer specialist throughout adulthood. This care will include getting tests on a regular basis to look for late effects. When your child completes treatment, ask your doctor or nurse for a record of the cancer treatment. This record will help other health-care providers know which long-term side effects to look for in the future.

Information adapted from the Family Handbook for Children with Cancer, CureSearch/Children's Oncology Group. 5/2007

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