|
From Late Breaking News 2008
National Wilms Tumor Study Newletter
Considerations for Living with One Kidney
by Michael Ritchey, MD
When physicians speak of kidney function they normally refer to the glomerular
filtration rate (GFR). This is a test that can accurately measure the level
of the kidney function. In most patients who have the kidney removed,
the glomerular filtration rate by the remaining kidney will increase. This is a process of compensation in which the solitary kidney makes up for its missing mate. This adaptive response by the kidney is both beneficial and potentially harmful.
The main function of the kidneys is to filter the plasma and to eliminate waste products. A normal solitary kidney can usually handle this task very well. Another function of the kidney is to help regulate the blood pressure. The kidney helps regulate salt excretion. It also produces some hormones that can affect blood pressure.
In addition to the surgical effects of removing kidney tissue, the treatments
for childhood renal cancer can affect kidney function. Some chemotherapy
agents can injure the kidney. This can occur temporarily but can also be permanent. Radiation therapy that may be needed to treat the cancer can also affect kidney function particularly if the remaining kidney was included in the radiation field. The effect of radiation is very dependent on the dose of the radiation therapy used. Fortunately, fewer patients currently being treated for Wilms tumor receive radiation therapy;
those who are irradiated are given lower doses than in the past.
Overall, the incidence of overt renal failure where patients require active treatment for inadequate kidney function is very low, less than 1%. Patients who have treatment for a single renal tumor in one kidney rarely develop late renal failure. The rate is higher in those with tumors in both kidneys.
In addition, some particular patients are at increased risk. These include children with certain genital anomalies or rare syndromes such as aniridia or the Denys-Drash syndrome. These latter patients have an inherent risk for renal failure due to an inherited specific disorder of the kidney.
All patients who undergo treatment for Wilms tumor should have long-term follow-up including annual measurements of blood pressure and urinalysis and blood test to assess kidney function. If there is elevation of the blood pressure, then prompt referral to a nephrologist, that is a kidney specialist, is warranted. Early intervention to lower blood pressure can prevent progression of kidney disease. Likewise, measurement of protein in the urine is extremely important because this a first sign of kidney failure. Again, referral to the nephrologist and early active treatment is recommended. The nephrologist may make specific recommendations regarding diet and avoidance of other risk factors that may affect kidney function.
Additional information can be found at the Children’s Oncology Group (COG) website. The COG has developed guidelines for follow-up of children treated for childhood cancer. These are risk-based, exposure-related recommendations
for the identification and management of late effects due to therapies used for childhood cancer. They are designed for asymptomatic survivors presenting for routine medical follow-up two or more years after completion of cancer therapy. Patient education materials called “Health Links” accompany the guidelines; both the guidelines and Health Links can be downloaded from www.survivorshipguidelines.org.
|
Sign up for the National Wilms Tumor Study Newsletter
"Late Breaking News"
Email: nwtsg@fhcrc.org |
National Wilms Tumor Study
Fred Hutchinson Cancer Research Center
1100 Fairview Ave. N, M2-A876
PO Box 19024
Seattle, WA 98109-1024
Phone: (206) 667-4842 or (800) 553-4878
FAX: (206) 667-6623
Email: nwtsg@fhcrc.org
|
|
