- Childhood Cancer Name: Wilms tumor, Wilms´tumor, nephroblastoma.
- Childhood Cancer Localization: Kidneys
- Childhood Cancer Noticeable Symptoms: A mass, lump or swelling in the child´s abdomen, blood in the urine.
- Childhood Cancer Diagnostic method: Basic blood and urine test, abdominal ultrasound, CT scan, MRI.
- Childhood Cancer Treatment: Surgery, chemotherapy, radiation.
WILMS TUMOR IN A NUTSHELL
Wilms tumor is a cancer of the kidney, usually its one mass in one kidney, this is called unilateral. However, 5% of children can have in both kidneys or bilateral. Immature kidney cells multiply out of control resulting in a mass, by the time the kid is 3-4 years old the mass can destroy normal kidney cells and cause bleeding into the urine, and eventually becomes noticeable as a firm lump in the child´s abdomen.
Some birth defects and genetic mutations related to the WT1 gene are risk factor such as Aniridia (missing iris of the eye), Beckwith-Wiedemann syndrome (a condition associated with larger-than-normal internal organs). WAGR (marked by defects of the iris, kidneys, urinary tract, or genitalia and Denys-Drash syndrome (a defect of the genitalia).
Why is it called Wilms tumor? It is named after Max Wilms, a German doctor who wrote one of the first medical articles about the disease in 1899.
Explanation: The kidneys develop while the baby is still in the womb, at birth some kidney cell are not yet differentiated into different types of mature kidney cells. Generally by the time the kid is 3-4 years old all cells have properly mature. Sometimes immature cells multiply out of control, resulting in a mass and this is called Wilms tumor. As it grows it changes the normal shape of the kidney and it can also destroy normal kidney tissue and cause bleeding into the urine. In some cases, the tumor eventually becomes noticeable as a firm, smooth lump in the child’s side or abdomen.
Characteristics: Usually its one mass in one kidney, this is called unilateral. However, 5% of children can have in both kidneys or bilateral.
Factors that may increase the risk of Wilms´ tumor:
- Being African American
- Family history of Wilms´tumor
- It is slightly more common in girls than in boys.
- A missing iris of the eye (aniridia) is a birth defect that is sometimes associated with Wilms tumor.
- Beckwith-Wiedemann syndrome (a condition associated with larger-than-normal internal organs).
- WAGR (marked by defects of the iris, kidneys, urinary tract, or genitalia), chromosome 11p13 that involves the WT1 gene.
- Denys-Drash syndrome (a defect of the genitalia).
Testing for these mutations can help doctors determine the best treatment.
It is classified into two types:
- Favorable histology: 95% of Wilms tumors have favorable histology. Although the cancer cells in these tumors don’t look quite normal, there is no anaplasia. The chance of curing children with these tumors is very good.
- Unfavorable histology (Anaplasic Willms tumor). In these tumors, the look of the cancer cells varies widely, and the cells’ nuclei (the central parts that contain the DNA) tend to be very large and distorted. This is called anaplasia. Anaplasia is a marker of resistance to chemotherapy but whether it actually signifies aggressiveness in unknown.
And stages, the stages of Wilms’ tumor are:
- Stage I. The cancer is found only in one kidney and generally can be completely removed with surgery.
- Stage II. The cancer has spread to the tissues and structures near the affected kidney, such as fat or blood vessels, but it can still be completely removed by surgery.
- Stage III. The cancer has spread beyond the kidney area to nearby lymph nodes or other structures within the abdomen, and it may not be completely removed by surgery.
- Stage IV. The cancer has spread to distant structures, such as the lungs, liver, bones or brain.
- Stage V. Cancer cells are found in both kidneys.
Signs and Symptoms:
- Most children do not show any signs or symptoms before being diagnosed
- A mass, lump or swelling in the child´s abdomen.
- Abdominal pain
- Blood in the urine, abnormal urine color.
- High blood pressure (Triggered when the tumor blocks the blood supply of the kidney)
- General discomfort.
- Nausea, loss of appetite, fever.
- The mean age of diagnosis is 3.5 years old.
- Frequently tumors are not diagnosed until they have become big, children often present with an asymptomatic abdominal mass, found by caregivers or pediatricians or Hematuria (blood in the urine) if the renal pelvis (kidneys) is invaded.
- The doctor will review the child´s symptoms and medical history.
Laboratory test include:
- Basic blood and urine test: BUN, complete blood count, creatinine, creatinine clearance.
- Abdominal Ultrasound: usually the first tool used to diagnose the condition
- Computed tomography (CT) scan of the abdomen: t is extremely useful in detecting tumors and determining whether cancer has spread to other areas.
- Magnetic resonance imaging (MRI): important to detect if cancer has invaded any major blood vessels near the kidney.
- Chest X ray
Treatment: It is determined by many factors, the most important is the stage of the tumor at the time of diagnosis. Treatment for Wilms includes surgery, chemotherapy, and possibly radiation, depending on how far cancer has spread. Surgery is most often used to treat Wilms tumor. For stages I through IV.
Types of Surgery
- Radical Nephrectomy
- Nephron-sparing surgery or partial nephrectomy.
Bilateral Wilms tumor
- It is a particular challenge, aggressive surgical resection is necessary to prevent but must be balanced with the desire to preserve renal function.
Follow up, late effects:
After the patient finishes the treatment, there is still need for follow up, the potential late effects depend upon the type of therapy, the kidney function and the stage of the tumor.
The main goals include:
- Reducing risk of second cancers.
- School and learning issues.
- Emotional support.
Link for more information:
- gov– General and medical information.
- Web page created by patients with Wilms tumor where they share their histories. http://www.ped-onc.org/hp/wilmspages.html
- The Children’s Oncology Group (COG), a National Cancer Institute supported clinical trials group, is the world’s largest organization devoted exclusively to childhood and adolescent cancer research. Here you can find follow up recommendations for kidney health according to the chemotherapy of choice: https://childrensoncologygroup.org/index.php/organs/kidneyhealth
- Wilms tumor trials on ClinicalTrials.gov: https://clinicaltrials.gov/ct2/results?term=wilms+tumor&recr=Open&no_unk=Y
- Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/wilms-tumor/symptoms-causes/syc-20352655
- Medline plus: https://medlineplus.gov/wilmstumor.html