What is Wilms?
A cancer of the kidneys.
Sometimes a mistake happens as kidneys grow. Some of the cells that are supposed to become glomeruli and nephrons don't mature. Instead, they stay like the early kidney cells [embryonal renal tissue]. Small or large bunches of these early kidney cells are still there when the baby is born. Most of the time these cells mature by the time a child is three or four. But these early kidney cells may start to grow out of control. They grow into a jumbled mixture of small cells that don't mature into nephrons and glomeruli. This mass is called a Wilms' tumor.
One of the most common types of childhood cancer, it affects approximately 1 child in every 10,000. Wilms' tumours can be found in one kidney [uni-lateral] or both kidneys [bi-lateral]. Roughly, only 5 percent of Wilms' cases are tumours in both kidneys [bi-lateral].
It is named after the German doctor, Max Wilms [1867-1918], who wrote a medical paper on children's kidney tumours in 1899.
CureSearch section on Wilms (which you'll find under "For Parents/Family" and choosing "Kidney and Wilms Tumor" in the drop down list).
What are the kidneys and what do they do?
The kidneys remove waste from the body, regulate blood pressure and electrolyte balance, and stimulate the production of red blood cells. Shaped like kidney beans, the organs are found on either side of the backbone. Inside each kidney are tiny tubes that filter and clean the blood, taking out the waste, and making urine. The urine made by the kidneys passes through a tube called a ureter into the bladder where it is held until it is voided from the body.
Click on the images below to see a bigger picture.
Healthy Adult Kidney |
4yr old Kidney with Wilms' |
What do Prognosis and Protocol mean?
Prognosis is the prediction of the course and outcome of a disease. For Wilms', the prognosis is generally very good. More than 85 percent cure rate. Quite a bit depends, though, on the staging of the tumours and the histology of the tumours.
The Protocol is the specific course or formula for treating a specific type of cancer. Again, each protocol will differ depending on the histology and staging of the tumours.
What is Histology and Staging?
Histology are the types of cancer cells within the Wilms' tumour.
If they are favourable, it means they respond well to conventional therapy. Favorable histology (FH): This is present in 90% of cases. All 3 histological elements are present without any anaplastic features. The cure rate is close to 90%.
If they are unfavourable, it means they are a more agressive cancer type and do not respond well to conventional therapy. Unfavorable histology (UH): This is present in 10% of the cases. Clear cell carcinoma of the kidney (bone-metastasizing renal tumor of childhood) and rhabdoid tumor of the kidney are now considered distinct type tumors and should not be included.
Anaplasia is defined by nuclear enlargement, nuclear hyperchromasia, and abnormal mitoses.
Focal anaplasia is present if less than 10% of the specimen has anaplastic features.
Diffuse anaplasia is present if more than 10% of the specimen has anaplastic features.
Nephrogenic rests are foci of abnormally present nephrogenic renal blastemal cells (metanephric blastema). These are considered precursors of Wilms tumor. Nephroblastomatosis is the diffuse presence of nephrogenic rests. It may be perilobar; intralobar (usually the more primitive elements are situated intralobarly), which has been associated more frequently with the development of Wilms tumor than the perilobar blastemal rests; or panlobular.
Staging is the description of the size and shape [type] of the tumours:
Stage 1:
Cancer is found only in the kidney and can be completely removed by surgery.
Stage 2:
Cancer has spread to the areas near the kidney, such as to fat or soft tissue, to blood vessels, or to the renal sinus (a large part of the kidney through which blood and fluid enter and exit the kidney). The cancer can be completely removed by surgery.
Stage 3:
Cancer has spread to areas near the kidney, but cannot be completely removed by surgery. The cancer may have spread to important blood vessels or organs near the kidney or the cancer may have spread throughout the abdomen, so that the doctor cannot remove all the cancer during surgery. The cancer may also have spread to the lymph nodes (small bean-shaped structures found throughout the body that produce and store infection-fighting cells) near the kidney.
Stage 4:
Cancer has spread to organs further away from the kidney, such as the lungs, liver, bone, and brain.
Stage 5:
Cancer cells are found in both kidneys.
[Note: While bi-lateral Wilms is technically a Stage 5, many times, however, the tumours on each kidney will be staged separately so, for example, it's not uncommon to hear that a bi-lateral Wilms was diagnosed as a Stage 1 on the left and Stage 3 on the right as opposed to being called a Stage 5].
How is Wilms' Tumour treated? What is the protocol?
INDIVIDUALS AT HIGH RISK FOR WILMS TUMOR
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