Wilms’ tumor, also known as nephroblastoma, is a rare type of kidney cancer. It usually affects children before the age of 6 years. It is very rare in adults.
Named after Max Wilms, a German doctor who first described it in 1899, it is the most common kidney tumor in those aged under 15 years.
This article will cover basic information on Wilms’ tumors, what they are, the signs and symptoms, diagnosis, and treatment.
Fast facts on Wilms’ tumor
Here are some key points about Wilms’ tumor.
Wilms’ tumor is a very rare kidney cancer that mainly affects children.
The outlook for Wilms’ tumor is typically good.
Symptoms include a swollen abdomen and blood in the urine.
Genetic factors may be involved, and the tumors may begin developing while in the womb.
Treatment usually involves surgery, chemotherapy, and occasionally radiation therapy.
Around 500 cases are reported per year in the United States.
What is a Wilms’ tumor?
Wilm’s tumors develop in the kidneys of children. They may start forming before birth.
Wilms’ tumors are rare, but they are the most common malignant tumors of the kidneys in children. If a tumor appears in a child, there is a 90-percent chance that it will be a Wilm’s tumor.
They occur around the ages of 3 to 4 years and only very rarely after the age of 6 years. About 500 cases are reported in the United States each year.
Over three-quarters of cases occur in otherwise healthy children, while one quarter are linked to other developmental problems.
Treatment usually has a high success rate. Over 90 percent of those who undergo treatment will survive at least 5 years.
In 95 percent of cases, the tumor affects one kidney, although there may be more than one tumor. In 5 percent of cases, it affects both kidneys. It is thought to develop from immature kidney cells.
The tumors are believed to result from the loss or inactivation of a tumor suppressor gene called QT1 on chromosome 11. Tumor suppressor genes usually hold back tumor growth and control cell growth.
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During the early stages, there may be no symptoms at all, and even a fairly large tumor may be painless. However, even large tumors are usually found before they start to metastasize, or spread to other parts of the body.
If symptoms occur, there may be:
a swelling in the abdomen
blood in the urine and abnormal urine color
high blood pressure
abdominal or chest pain
large and distended veins across the abdomen
malaise, or feeling unwell
unexplained weight loss
If the tumor has spread to the lungs, there may also be coughing, blood in the sputum, and difficulty breathing.
There are a variety of operations that might be used for Wilms’ tumor.
Options include nephrectomy, which is the surgical removal of kidney tissue.
Simple nephrectomy: The whole kidney is surgically removed. The other kidney is enough to maintain the patient in good health.
Partial nephrectomy: The tumor and part of the kidney tissue that surrounds it is surgically removed. This type of surgery is done if the other kidney is not 100 percent healthy, or has already been surgically removed.
Radical nephrectomy: The whole kidney, nearby adrenal gland and lymph nodes, as well as other surrounding tissue are surgically removed.
During the procedure, the surgeon may check both kidneys, as well as the abdominal cavity. Samples may be taken for testing.
Other options include:
Kidney transplant: If both kidneys need to be taken out, dialysis will be needed until a transplant can be carried out.
Chemotherapy: The tumor cells are examined to determine whether they are aggressive or susceptible to chemotherapy, the use of medication to kill cancer cells. Cytotoxic medication prevents cancer cells from dividing and growing.
Chemotherapy targets unwanted cancer cells, but it can also affect healthy cells, and side effects may result.
loss of appetite
low white blood cell count
Once the treatment finishes, side effects usually go away.
High-dose chemotherapy can destroy bone marrow cells. If a high dose is needed, marrow cells may be removed, frozen, and returned to the body intravenously after the treatment.
Radiation therapy: Beams of high-energy X-rays or particles of radiation are used to destroy cancer cells. Radiation therapy works by damaging the DNA inside the tumor cells. This destroys their ability to reproduce.
Radiation therapy usually begins a few days after surgery. Very young patients may be given a sedative so that they are still during a radiotherapy session. The doctor marks the targeted area with a dye, while shielding non-targeted areas of the body.
The following side effects are possible:
Diarrhea: If the abdomen is targeted, symptoms may occur a few days after starting treatment. As treatment progresses, symptoms may get worse, but they usually disappear few weeks after completing the course.
Fatigue: This is the most common symptom.
Nausea: This may occur at any time during treatment or for a short time after. It is important to tell the doctor because it is easily treatable with medication.
Skin irritation: Areas targeted by the radiation beam may become red and sore. These areas should be protected from sunlight, cold winds, from scratching and rubbing, and from perfumed soaps.
Staging is used to assess how far the cancer has grown or spread.