Wilms tumor

Wilms tumor

Overview

Wilms tumor is a rare kidney cancer that mainly affects children. Also known as nephroblastoma, it's the most common cancer of the kidneys in children. Wilms tumor most often affects children ages 3 to 4. It becomes much less common after age 5, but it can affect older children and even adults.

Wilms tumor mostly occurs in just one kidney. But it can sometimes be in both kidneys at the same time.

Over the years, progress in the diagnosis and treatment of Wilms tumor has greatly improved the prognosis for children with this disease. With treatment, the outlook for most children with Wilms tumor is good.

Symptoms

Symptoms of Wilms tumor vary a lot. Some children don't seem to have any symptoms. But others with Wilms tumor have one or more of these symptoms:

A mass in the stomach area that can be felt.

Swelling in the stomach area.

Pain in the stomach area.

Other symptoms might include:

Fever.

Blood in the urine.

Low red blood cell level, also known as anemia.

High blood pressure.

Causes

It's not clear what causes Wilms tumor.

Cancer begins when cells develop changes in their DNA. Cells' DNA holds the instructions that tell the cells what to do. The changes tell the cells to grow and multiply quickly. The cancer cells live while healthy cells die as part of their natural life cycle. With Wilms tumor, the changes make extra cells in the kidney that form the tumor.

Rarely, DNA changes passed from parents to children can increase the risk of Wilms tumor.

Risk factors

Factors that may increase the risk of Wilms tumor include:

Being Black. In North America and Europe, Black children have a slightly higher risk of getting Wilms tumor than do children of other races. Asian-American children appear to have a lower risk than children of other races.

Having a family history of Wilms tumor. Having someone in the family who's had Wilms tumor increases the risk of getting the disease.

Wilms tumor occurs more often in children who have certain conditions present at birth, including:

Aniridia. In aniridia (an-ih-RID-e-uh), the colored portion of the eye, known as the iris, forms only in part or not at all.

Hemihypertrophy. Hemihypertrophy (hem-e-hi-PUR-truh-fee) means one side of the body or a part of the body is larger than the other side.

Wilms tumor can occur as part of rare syndromes, including:

WAGR syndrome. This syndrome includes Wilms tumor, aniridia, genital and urinary system problems, and intellectual disabilities.

Denys-Drash syndrome. This syndrome includes Wilms tumor, kidney disease and male pseudohermaphroditism (soo-do-her-MAF-roe-dit-iz-um). In male pseudohermaphroditism, a boy's genitals aren't clearly male.

Beckwith-Wiedemann syndrome. Children with this syndrome tend to be much larger than what is typical, known as macrosomia. This syndrome might cause organs in the stomach area to jut into the base of the umbilical cord, a large tongue, large internal organs and ears that are formed unusually.

Diagnosis

To diagnose Wilms tumor, a health care provider might take a family history and do the following:

A physical exam. The provider will look for possible signs of Wilms tumor.

Blood and urine tests. These lab tests can show how well the kidneys are working.

Imaging tests. Tests that create images of the kidneys help find whether a child has a kidney tumor. Imaging tests may include ultrasound, CT scans or MRI and chest X-rays.

Staging the cancer

After finding Wilms tumor, the health care team might recommend other tests to see if the cancer has spread. This is called the cancer's stage. A chest X-ray or chest CT scan and bone scan can show whether the cancer has spread past the kidneys.

The stage of the cancer helps with deciding treatment. In the United States, the stages for Wilms tumor are:

Stage 1. The cancer is found only in one kidney. Surgery can remove it all.

Stage 2. The cancer has spread beyond the kidney, such as to nearby fat or blood vessels. But surgery can still remove it all.

Stage 3. The cancer has spread beyond the kidneys to nearby small organs that fight infection, also known as lymph nodes. It might also have spread to other places within the abdomen. The cancer cells might spill within the abdomen before or during surgery, or surgery might not be able to remove all the cancer.

Stage 4. The cancer has spread outside the kidney to other places in the body, such as the lungs, liver, bones or brain.

Stage 5. Cancer cells are found in both kidneys. The tumor in each kidney is staged by itself.

Treatment

Treatment for Wilms tumor usually involves surgery and chemotherapy. It sometimes includes radiation therapy. Treatments depend on the stage of the cancer. Because this type of cancer is rare, a children's cancer center that has treated this type of cancer might be a good choice.

Surgery

Treatment for Wilms tumor may begin with surgery to remove all or part of a kidney. Surgery also confirms the diagnosis. The tissue removed during surgery is sent to a lab to learn whether it's cancerous and what type of cancer is in the tumor.

Surgery for Wilms tumor may include:

Removing part of the kidney. Known as a partial nephrectomy, this involves removing the tumor and a small part of the kidney around it. This might be done if the cancer is very small or for a child who has only one working kidney.

Removing the kidney and surrounding tissue. Known as a radical nephrectomy, this type of surgery also involves removing nearby lymph nodes, part of the ureter and sometimes the adrenal gland. The kidney that's left can take on the work of both kidneys.

Removing all or part of both kidneys. If the cancer affects both kidneys, surgery involves removing as much cancer as possible from both. Sometimes, this means removing both kidneys. The child would then need kidney dialysis or a kidney transplant.

Chemotherapy

Chemotherapy uses strong medicines to kill cancer cells throughout the body. Treatment for Wilms tumor usually involves using more than one medicine to kill cancer cells. The medicine is given through a vein.

Side effects of chemotherapy depend on the medicines used. Common side effects include nausea, vomiting, loss of appetite, hair loss and higher risk of infections. Ask your child's health care team what side effects might happen during treatment. Ask if there might be long-term problems as a result of treatment.

If given before surgery, chemotherapy can shrink tumors and make them easier to remove. After surgery, it can kill cancer cells that are left in the body. Chemotherapy may also be an option for children whose cancers are too far along to be removed completely with surgery.

For children who have cancer in both kidneys, chemotherapy is given before surgery. This may make it more likely that one kidney might be saved.

Radiation therapy

Some children might have radiation therapy. Radiation therapy uses high-powered energy beams to kill cancer cells. The energy can come from X-rays, protons and other sources.

During radiation therapy, the child is placed on a table. A large machine moves around the child, pointing energy beams at the cancer. Possible side effects include nausea, diarrhea, tiredness and sunburn-like skin irritation.

Some children will have radiation therapy after surgery to kill any cancer cells that are left. It also might be used to control cancer that has spread to other areas of the body. Ask if there might be long-term problems as a result of radiation therapy.

Type of Doctor Department : A pediatric surgeon or pediatric urologist,  a pediatric oncologist