Renal and Genito-Urinary
Nephrectomy
Nephrectomy is associated with long term health risks:
- Renal failure
- Hyperfiltration injury
- Hypertension
- Hydrocele
Compensatory hypertrophy of the remaining kidney occurs after nephrectomy.
- Initial increase of glomerular filtration capacity
- Possible long term glomerulosclerosis and interstitial injury leading to deterioration of renal function.
Childhood cancer therapy includes other agents which contribute to renal failure:
- Chemotherapy (cisplatin, carboplatin, ifosfamide)
- Other drugs (e.g., aminoglycoside antibiotics, amphotericin, cyclosporine)
- Abdominal radiotherapy may also contribute to impaired renal function.
In the few small studies focusing on renal function in survivors of Wilms tumor, clinically relevant reductions in GFR after nephrectomy are rarely seen.
However, the method used to assess GFR may affect the prevalence rates of renal insufficiency.
One study reported no statistically significant differences in mean GFR between children
who underwent nephrectomy for Wilms tumor or neuroblastoma (median follow-up after nephrectomy, 12 and 9 months, respectively) and children of comparable age who underwent nephrectomy for non-malignant disease (median follow-up after nephrectomy,
23 months). However, 50% of the childhood cancer survivors who underwent nephrectomy had chronic renal insufficiency (defined as GFR<90 ml/min/1.73 m2).
A comparison between children with Wilms tumor who did or did not receive RT,
demonstrated lower GFR in the irradiated group (73% of normal) than in the non-irradiated group (95%of normal) In this study, prevalence of chronic renal insufficiency was 34%.
Long term survivors of WT whose GFR measurements are decreased are more likely to have received higher doses of RT, and have poorer renal growth (measured by renal ultrasound).
The frequency of microalbuminuria, which is indicative of glomerular hyperfiltration, following nephrectomy is less clear. This complication has been reported to be present in 5–84% of cases.
Diastolic hypertension may also be a late effect of treatment that includes nephrectomy. In an analysis of 1,171 children treated for Wilms tumor whose blood pressure was measured 5 years after diagnosis, 83 (7%) had a diastolic blood pressure above the 95th percentile for age. However, a substantial proportion of patients with diastolic hypertension had also received abdominal RT; therefore, the relative contribution of nephrectomy to this complication is unclear.
Hydrocele has recently been recognized to be a sequela of nephrectomy. Sixteen percent (9 of 57) of male survivors of Wilms tumor were found to have hydroceles, all on the same
side as the nephrectomy. This risk appears to be unrelated to previous nephrectomy.
Many childhood survivors of Wilms tumor who develop chronic renal failure have syndromes accompanying WT1 mutations or deletions that pre-dispose to renal disease.
Breslow et al. recently assessed the risk of end-stage renal disease (ESRD) in Wilms tumor survivors and found that, although the overall incidence was 1% for unilateral tumor and 12% for bilateral tumors, patients with Denys–Drash syndrome, Wilms tumor aniridia syndrome or associated genitourinary anomalies had ESRD risks as high as 90%.
