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Kidney problems can develop after some types of cancer treatment. Sometimes kidney problems happen as a late effect of treatments for cancer during childhood.
How the kidneys work
The kidneys are part of the urinary system. They are 2 bean-shaped organs, each about the size of an adult fist. They are below the ribcage near the middle of the back. The kidneys filter waste products from the blood, control blood pressure and stimulate red blood cell production.
The blood is filtered in tiny units inside the kidneys, known as nephrons. Each kidney has approximately 1 million nephrons. After the nephrons filter the blood, the extra water and waste products become urine. The urine flows from the kidneys to the bladder through tubes called ureters. The bladder then stores the urine until it is full. Then the urine is emptied from the body through the urethra.
Kidney function is measured in percentages. When both kidneys are working normally, it is referred to as 100% kidney function. One kidney working normally is about 50%. A person can lead a normal life with one healthy kidney. If kidney function drops below 50%, there is a risk of health problems.
Treatments for cancer, including some types of chemotherapy, radiation therapy and stem cell transplants, can cause kidney problems.
The kidneys break down and remove chemotherapy drugs from the body. The products from this process can damage the cells in the kidneys, ureters and bladder. A treatment that is toxic to the kidney is called nephrotoxic. Whether or not a chemotherapy drug will cause kidney damage depends on the dose of the drug, if other drugs are used at the same time and if you already have kidney disease.
Chemotherapy drugs that are known to be nephrotoxic include:
- carboplatin (Paraplatin, Paraplatin AQ)
- ifosfamide (Ifex)
Radiation therapy to the kidney or abdomen or total body irradiation (TBI) given before a stem cell transplant can cause damage to the kidneys.
Stem cell transplant
The preparation for a stem cell transplant includes high doses of chemotherapy and sometimes TBI, which can damage the kidneys. Certain medicines used to treat graft-versus-host disease (GVHD) after a stem cell transplant also increase the risk of kidney problems.
The following may also increase the risk of kidney problems:
- surgery to remove all or part of a kidney
- surgery to remove the bladder
- having cancer in both kidneys
- age at the time of treatment (the younger the child, the greater the risk)
- certain antibiotics and antifungal drugs
- medical conditions such as diabetes and high blood pressure
- urinary tract problems such as frequent urinary infections or backflow of urine into the kidney (known as reflux)
Types of kidney problems
Kidney problems that can develop after treatment for cancer include:
- kidney dysfunction, which means the kidneys aren’t working as well as they should
- high blood pressure
- chronic kidney disease
- kidney failure
Symptoms can occur during treatment and may be temporary. Kidney damage can be mild to severe and may become permanent. If the damage is severe, it can lead to kidney failure.
Signs and symptoms that may mean the kidney is damaged or not working normally include:
- swelling of the hands, ankles, feet or other areas of the body
- high blood pressure
- changes in urination and less amount of urine
- rapid heart rate
- rapid breathing
- metal-like taste in the mouth or bad breath
- itchy skin
- nausea or vomiting
If symptoms get worse or don’t go away, report them to your doctor or healthcare team without waiting for your next scheduled appointment.
Before treatment for cancer begins, the healthcare team may do tests to check your kidneys and make sure there are no major problems. Tests may also be done during treatments to make sure nothing has changed.
Kidney problems are usually diagnosed by:
- a physical exam, including measuring blood pressure
- a urinalysis
- a complete blood count
- blood chemistry tests
- an ultrasound of the kidney
Find out more about tests and procedures.
Preventing and managing kidney problems
The healthcare team takes measures to help prevent and manage kidney problems that may occur because of cancer treatment.
The following steps can help prevent and manage kidney problems during treatment:
- Extra fluids may be given intravenously to help flush the waste produced when the kidneys break down the chemotherapy drugs.
- Fluid and electrolyte levels in blood or urine samples are checked so the healthcare team can tell how well the kidneys are working.
- Certain medicines, such as amifostine (Ethyol), may be given to protect the kidneys from damage when nephrotoxic chemotherapy is given.
- The dose of the drug may be lowered or the drug may be stopped completely if there is kidney damage.
- If severe kidney damage occurs and causes the kidneys to fail, dialysis may be needed to clean waste products from the blood.
Tell the healthcare team about any swelling that happens suddenly and about any changes in urination.
If your kidneys have been damaged from cancer treatment you will have to take precautions and protect your kidneys for the rest of your life.
Taking the following steps can help prevent kidney problems:
- Be aware of signs and symptoms of dehydration, which is when the body loses too much water.
- Drink plenty of fluids to ensure a regular flow of urine.
- Replace your electrolytes on an ongoing basis if needed.
- Get treatment for high blood pressure if needed.
- Check with your doctor or pharmacist before taking any new medicines.
- Get treatment for urinary tract infections right away.
- Talk to your doctor before taking part in contact sports.
All people who are treated for cancer need regular follow-up. The healthcare team will develop a follow-up plan based on the type of cancer, how it was treated and your needs.
Make sure you tell your doctor all the treatments you received. You may have a physical exam including checking your blood pressure. Other tests may include a urinalysis and blood tests to check how well your kidneys are working.
Reducing the burden of cancer
Canadians can help CCS fund the best research and support people living with cancer by donating and volunteering.