Late effects are generally defined as side effects which occur 5 years or more after therapy. All cancer treatment is associated with adverse effects. Treatment of Wilms tumor, however, is relatively mild and usually produces minimal toxicity.
Late Effects associated with flank and whole abdominal RT:
| Organ at risk | Toxicity |
Growth abnormalities and hypoplasia:
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Increased risk of osteoporosis (especially involving the spine) and degenerative disease:
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| Pancreas | Metabolic syndrome is more common after RT to the upper abdomen. This is characterized by:
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There is a small long term risk of veno-occlusive disease which consists of the clinical triad:
Increased risk in children with right sided tumor (larger volume of liver irradiated in the flank field)
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If included in the RT treatment volume, stenosis of the contralateral renal artery may produce hypertension.
It is very important to check Wilms tumor survivor's blood pressure on a regular basis
Patients with bilateral Wilms Tumor undergoing partial nephrectomy and RT are at significantly increased risk of chronic renal failure
Patients are likely to have sufficient renal tissue for normal growth and development for many years.
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Ovary:
Ovarian failure very rare in females who receive abdominal RT to a volume that does not include both ovaries (risk of early menopause though). Ovarian failure
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Even when the area is shielded or excluded, whole abdominal RT is associated with a risk of:
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| Pregnancy Outcome | Female patients who had RT have a higher risk of premature births.
RT is also associated with:
No significant increase of congenital anomaly or Wilms tumor in offspring of WT survivors.
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Late Effects associated with pulmonary RT:
Mild scoliosis and mild asymmetry of all musculoskeletal structures in the RT field can occur due to reduced growth of bone and paravertebral muscles
There will be a decrease in sitting height and modest decrease in standing height after flank or abdominal RT
If the child is very young there may be a mild restrictive problem due to reduced growth of the chest wall and ribs
In female children there may well be subsequent breast hypoplasia (under-development)
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Bilateral whole-lung RT is associated with decreased:
12 to 14 Gy has been shown to reduce total lung capacity and vital capacity to about 70% of predicted values (and even lower if the patient had also had thoracotomy)
Airways are relatively unaffected
Patients who have received pulmonary RT are especially at risk for chronic obstructive airways disease and lung cancer if they smoke
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| Thyroid | If the lungs are irradiated then the thyroid will receive some scattered radiation
Increased risk of hypothyroidism, thyroid nodules and papillary carcinoma of the thyroid.
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RT-related heart damage is rare in survivors of Wilms tumor treated using current protocols.
Incidence of cardiomyopathy is higher in children when they have received mediastinal RT or RT that included the ventricles
Congestive heart failure in children:
Doxorubicin and thoracic RT for Wilms tumor results in a risk of congestive heart failure of 4.4% at 20 years after diagnosis
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Surgery Late Effects:
After unilateral nephrectomy in childhood, the remaining kidney generally adjusts its function and size: “compensatory hypertrophy of the kidney”
A year after treatment, the glomerular filtration rate and effective renal plasma flow are around 90% of normal values.
Children treated with surgery and chemotherapy alone have close to normal values for GFR.
Proteinuria and hypertension may occur in the long term after a combination of nephrectomy, chemotherapy and significant radiotherapy.
In long term follow up, it is important to check:
- Blood pressure (a solitary kidney is associated with an increased risk of hypertension)
- Renal function using routine blood tests and urinalysis
It is also important to warn about the prompt treatment of urinary tract infections (there is no increased risk, but infection could potentially damage remaining renal tissue).
Patients who have had a nephrectomy should avoid activities that might damage the remaining kidney and it is reasonable to avoid contact sports.
COG Survivorship guidelines: Keeping your single kidney healthy
Chemotherapy Late Effects:
Adriamycin (ADR)
- Significant cardiac toxicity is very infrequent in Wilms tumor survivors.
- Risk following ADR administration is greater when the myocardium has been irradiated in the course of either whole lung or abdominal irradiation.
- Damage may be pericardial, myocardial, and/or vascular.
Vincristine (VCR)
- Peripheral Neuropathy
COG survivorship guidelines: Kidney health after childhood cancer
