Wilms tumor named after Max Wilms, a German doctor who wrote one of the first medical articles about the disease in 1899.
Wilms tumor is a cancer of the kidney. Usually its one mass in one kidney, it is called unilateral. However, 5% of children can have in both kidneys or bilateral.
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 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.
It is classified into two types:
- Favorable histology: 95% of Wilms tumors have favorable histology. Although the cancer cells in these tumors do not 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 is actually signifies aggressiveness, is unknown.
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 found in both kidneys.
Childhood Cancer Diagnostic method:
Basic blood and urine test, abdominal ultrasound, CT scan, MRI.
- 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.
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.
Childhood Cancer Treatment:
It is determined by many factors, when the most important is the stage of the tumor at the time of diagnosis.
Treatments for Wilms include 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.