It is important to remember that a given individual with WAGR syndrome may or may not have or develop the condition listed below. |
Wilms' tumor is the most common form of kidney cancer in children. There are about 500 cases of Wilms' tumor diagnosed in the US each year. Of these, about 4 to 5 will be children with WAGR syndrome. Wilms' tumor is highly curable, particularly if discovered at an early stage.
Approximately 50% of children with WAGR syndrome will develop Wilms' tumor. It is not possible to predict which children with WAGR syndrome will have Wilms' tumor, so periodic screening is very important. This screening usually consists of abdominal ultrasound examinations, beginning at birth and continuing every 3 months until at least age 6 to 8. Some physicians also advocate training parents to examine the child’s abdomen between ultrasounds.
In children with WAGR syndrome, Wilms' tumor tends to occur at an earlier age than in typical children. The average age of diagnosis of Wilms' tumor in children with WAGR syndrome is 17-28 months. Most cases of Wilms' tumor in children with WAGR syndrome are diagnosed by age 3. However, there have been cases of Wilms' tumor in children with WAGR syndrome up to age 12, and one case was documented at age 25. For this reason, some form of monitoring should be continued throughout life, such as ultrasound examinations every 6 to 12 months, and/or observing the child/adult for symptoms such as:
- A lump or mass in the abdomen
- Abdominal pain
- Blood in the urine
- High blood pressure
- Fever
- Diarrhea
- Weight loss
- Urogenital infections
- Anemia
- Shortness of breath
- A general feeling of being tired and unwell
- Nausea and vomiting (these last two are rare)
With screening, most Wilms' tumors in children with WAGR syndrome are diagnosed at an early stage. Even when diagnosed in later stages, the overall survival rate for Wilms tumor is more than 90%.
For more information about the diagnosis and treatment of Wilms' tumor from the National Cancer Institute in English & Spanish:
http://www.cancer.gov/cancertopics/pdq/treatment/wilms/patient
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| Special Considerations for Children with WAGR syndrome |
1. Nephrogenic Rests, Nephroblastomatosis
2. Chemotherapy
3. Late-onset Renal Failure
The treatment of children with WAGR syndrome who develop Wilms tumor is usually similar to that of typical children with Wilms tumor. However, children with WAGR syndrome may present some additional challenges.
These include:
1) Nephrogenic Rests/nephroblastomatosis
2) Possible increased sensitivity to Vincristine
3) Consideration for partial nephrectomy (removal of only part of the kidney)
Nephrogenic Rests are very common in the kidneys of children with WAGR syndrome.
Nephrogenic rests are clusters of abnormal cells in the kidneys. They represent embryonic tissue which has failed to mature and develop properly. When there are many of these clusters of cells, the condition is called “Nephroblastomatosis.” Nephrogenic rests are sometimes benign (not cancer) but can also sometimes become malignant (cancerous). Nephrogenic rests sometimes evolve into Wilms tumor.
Ultrasound and other imaging tests can help determine whether these clusters are present, and whether they are suspicious. In some children, nephrogenic rests are present for many years and do not cause any problems. In other children, it may be necessary to treat them with chemotherapy, or to remove them surgically.
Chemotherapy for Wilms tumor usually involves a drug called Vincristine. This drug has the potential to cause problems with the neurologic system in any patient. Although there have not yet been any studies specifically examining the use of this drug in children with WAGR syndrome, there have been several reports of episodes of ptosis (drooping of the eyelid). In some cases, it may be necessary to alter the dose or timing of this drug to resolve this problem.
The possibility of late-onset renal failure has led some physicians to advocate partial nephrectomy for children with WAGR syndrome and Wilms tumor, in order to maximize the amount of renal tissue left after treatment. Parents and physicians should be aware that renal failure occurs in children with WAGR syndrome who have never had Wilms tumor, and that no studies have been done to determine whether partial nephrectomy is a safe and effective alternative to current Wilms tumor protocols.
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| Wilms Tumor: Differences in Treatment |
Kelly Trout, RN, BSN
There are two basic approaches to the treatment of Wilms tumor: The North American approach, and the European approach.
In North America, the National Wilms Tumor Study Group and its successor, The Children’s Oncology Group, (COG) have studied Wilms tumor and its treatment since 1969. In general, the approach they’ve developed is:
1) Surgery immediately (unless bilateral tumors are present). Complete removal of the kidney is usual.
2) Examination of the tumor for staging
3) Post-operative treatment (i.e., chemotherapy, with radiation if needed) based on the stage of the tumor
In Europe and many other parts of the world, the International Society of Pediatric Oncology (SIOP) is the organization which studies Wilms tumor and has developed protocols for treatment. The general approach of this group is:
1) Staging of the tumor based on ultrasound/MRI
2) A period of chemotherapy (and radiation, if indicated)
3) Surgery
4) Post-operative treatment (i.e., chemotherapy, with radiation if indicated)
One benefit of the North American (COG) approach is that immediate surgery allows the tumor to be staged and the type of cells to be identified, with post-op treatment specific to the stage of the tumor.
The European (SIOP) approach has a couple of benefits, and one drawback. First, a benefit of preoperative chemotherapy is that it usually reduces the size of the tumor, which can decrease the amount of treatment needed after surgery. In addition, the patient’s response to preoperative chemotherapy can help determine the most appropriate treatment for them after the tumor is removed.
One difficulty with the SIOP approach is the small risk of misdiagnosis. Most patients no longer receive biopsy prior to treatment, and since the appearance of a mass on ultrasound and/or MRI can be misleading, approximately 5% of patients will ultimately be found not to have Wilms tumor.
Both of these approaches have similar outcomes – in other words, overall survival rates are excellent with either. So, “In the absence of a clear choice between up-front nephrectomy (removal of the kidney) and preoperative chemotherapy, it is reasonable to base the timing of resection (surgery) on factors such as tumor size, the patient’s clinical condition, and the experience of the surgeon.”
Metzger, ML, Dome, JS, Current Therapy for Wilms Tumor. The Oncologist 2005;10: 815-826.
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| Recommendations for Follow-up |
From “Late Breaking News” Newsletter of the National Wilms Tumor Study, Winter 2003
Anne Warwick, MD, and Yevgeny Grigoriev, MD
Recommended Annual Follow Up:
1) Complete Physical Examination
2) Blood Pressure Measurement
3) Laboratory Tests:
CBC
WBC Differential
Liver Function Tests (AST, ALT, Alk Phos, Bilirubin)
Renal Function Tests (BUN, Creatinine, GFR)
Urinalysis
If you received Adriamycin, also called Doxorubicin: Adriamycin can make the heart muscle weak. This is a cumulative effect, that is, the more medicine you received, the greater your chances of having a problem. The echocardiogram or MUGA scan will look to see how well your heart muscle is working. Pregnancy and sudden vigorous exercise can place strain on the heart. It is important to know, before entering into these activities, how well your heart is working. It will be important for your doctors to be aware and continue to monitor for this potential problem. A heart specialist (cardiologist) should be consulted and tests done such as MUGA scan or echocardiogram prior to engaging in any vigorous sports, planning pregnancy and during the last trimester of pregnancy.
If you had chest irradiation (girls): You may be at an increased risk for developing breast cancer. Mammography is one way to screen for early tumors. Mammograms should be done annually in mature women beginning ten years after chest irradiation. (Boys are not at increased risk of breast cancer if they received lung irradiation.)
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