Wilm's Tumor: A Childhood Cancer

By Mary J. Hamilton

Wilm's tumor is a rare kidney cancer that usually occurs only in children and rarely happens after the age of eight. It is named for a 19^th-century German surgeon who found the cause. It is now the most common form of kidney cancer in children, with an average 8 out of 1,000,000 people getting it. Wilm's tumor makes up about 6-7% of childhood cancer cases and only 2-5% are in both kidneys. The average age of a child with Wilm's tumor is 2-3 years old. There are signs that can be looked for to indicate if someone has Wilm's tumor.

Parents sometimes feel a lump or mass in the abdomen while they are dressing their child or a doctor might find it during an examination. The tumor can be firm and may be felt on both sides of the abdomen. A child with Wilm's tumor may seem fine and healthy for a while. The tumor can grow large without causing any pain or discomfort. Other than the mass, a child may have other symptoms. They could have a fever for unknown reasons, blood in the urine, a reduced appetite, weight loss, high blood pressure, constipation, stomach pain, nausea, vomiting and general discomfort. Most of the tumors aren't found until they have grown quite large, but most are also found before they metastasize. There are several ways that Wilm's tumor can be diagnosed.

A complete medical history and physical examination are needed, but an abdominal ultrasound may also be used. It creates images of blood vessels, tissues and organs. It can provide an outline of the kidneys and the tumor. An abdominal computed tomography scan, also called a CT or CAT scan, can also be used. A CAT scan uses a combination of X-rays and computer technology to create cross-sectional images, or slices, of the body. This can be used to get a more detailed picture of the kidney to see if there are any unusual growths on it or if it is enlarged. A magnetic resonance imaging system, or MRI, can be used to determine if the tumor has metastasized, if there are any tumor cells in the lymph nodes, or if there are any other organs infected. Wilm's tumor, since it can grow quite large, can compress other organs. This may affect the ability of other organs to perform their function.A chest x-ray can be used to determine if there are metastases, or spreading, in the lungs. Looking at images of the internal organs isn't the only way to diagnose Wilm's tumor.

As stated earlier, one of the symptoms of Wilm's tumor is blood in the urine. A blood and urine test can help evaluate kidney and liver function. Sometimes more information is needed and surgery may be required. A biopsy may be performed to get a sample of tissue. It is then examined under the microscope to evaluate cells, the extent of the disease and the diagnosis. While a sample of tissue can give some information about the condition of the kidney and the tumor, sometimes more is needed. Wilm's tumor is usually only found on one kidney and people are able to live on one kidney alone. If needed, they may do surgery and remove the tumor and kidney. This is also know as a nephrectomy. This can give them a definitive diagnosis and can help them determine how far the cancer has gone. Once they have their diagnosis and have determined just how far it has gone, they can begin treatment.

The most common surgery for Wilm's Tumor is surgery and chemotherapy. Depending upon the stage the cancer is in, radiation therapy might also be used. There are various kinds of nephrectomy; simple nephrectomy, partial nephrectomy, and radical nephrectomy. A simple nephrectomy is where the entire kidney is removed. The remaining kidney is able to take over the function of both by increasing its capacity. When the other kidney is damaged or has already been removed, a partial nephrectomy may be performed. It involves the removal of the tumor and part of the kidney tissue surrounding it. A radical nephrectomy is when the kidney is removed along with the surrounding tissues. The lymph nodes may be removed as well. Chemotherapy uses medication to kill cancer cells and comes in different forms; pill, an IV, or an injection. Chemotherapy enters the bloodstream and travels through the body, so it is considered systemic. As it travels through the body, it kills any cancer cells it may find. It also affects any other rapidly dividing cells, which also means it affects some healthy cells. Some of these cells include hair follicles, cells in the gastrointestinal tract and bone marrow. This can lead to nausea, vomiting, loss of appetite, hair loss and low white blood cell counts. When a high dosage of chemotherapy is received, which is not the usual practice, it can destroy bone marrow. A doctor may remove some of the bone marrow before the treatment and freeze it. It can then be returned by autologous bone marrow reinfusion, which is where the bone marrow is returned using an IV line. Chemotherapy isn't the only treatment with side effects.

Radiation therapy uses sources of high-energy rays, like X-rays, to kill cancer cells. It's usually done a few days after surgery. A sedative is sometimes given to the patient, usually very young children, to keep them still while they are receiving the treatment. The area to receive the treatment is marked with a special dye while the other areas are shielded. The side effects that can occur from radiation therapy include nausea, fatigue and skin irritation. They may also experience diarrhea and a sunscreen lotion should be applied after treatment to avoid sunburn. What type of treatment is received depends upon what stage the cancer is in.

Stage I or II cancer is where the cancer is only in or near the kidney and is not aggressive. A surgeon may perform a nephrectomy to remove the affected kidney. They may also remove the nearby tissues and some of the lymph nodes near the kidney if necessary. This treatment may also be followed up by chemotherapy to make sure any remaining cancer cells are killed. Some patients with stage II cancer also receive radiation therapy. Stage III or IV cancer is when the cancer has spread and can't be completely removed safely. Surgery will remove some of the cancer and chemotherapy may be done before to shrink it. After surgery, radiation and chemotherapy treatment will be given. Stage V is the most advanced stage of the cancer. When the cancer has reached stage V, and if the tumor is in both kidneys, part of the cancer from both kidneys will be removed. Lymph nodes that are nearby will also be removed to see if they contain any tumor cells. Chemotherapy is then used to shrink the tumor and surgery is performed again. The surgeon will leave the functioning kidney tissue, but try to remove as much of the tumor as possible. This may be followed by more chemotherapy and radiation treatment. With the advances in modern medicine, the prognosis for people with Wilm's tumor has increased.

Thanks to multimodal therapy, the survival rate of people with a small-sized tumor, favorable cell type, are in an early stage of the cancer or are very young is 93%. Patients with an anaplasia have a survival rate of 43% and people with a sarcoma have a survival rate of 36%, according to HealthAtoZ. Only about 8 in 1,000,000 people get the tumor. Wilm, the surgeon who discovered one of the causes, noticed that it seemed to be caused my immature kidney cells.

These cells usually mature as the child ages, but can become mutated and turn into Wilm's tumor. Most occur by chance, but some can be caused by genetics. A small percentage of people with Wilm's tumor have WAGR syndrome, Denys-Drash syndrome or Beckwith-Wiedemann syndrome. WAGR stands for the four diseases present, one of which is Wilm's tumor. The others are aniridia, genitourinary malformations and mental retardation. It can also be caused by birth defects like Hemihypertrophy, Cryptorchidism or Hypospadias. It is a good idea to screen any children with these birth defects or genetic diseases every three months until they are eight years old. It is important for both the doctors and the parents to be informed as possible.

They need to know the signs to look for, like the lump in the abdomen, fever and blood in the urine. While a non-invasive method like an MRI, CAT Scan or an X-ray may be used for diagnosis, it is important for parents to be prepared for a nephrectomy if needed. While surgery is hard on both the parents and the children, children tend to bounce back from surgery more easily. It is also important for parents to discuss the different treatment options with their doctor for whatever stage the cancer is in. Some parents might be wary of surgery and prefer to try chemotherapy or radiation therapy first. Families also have more hope now thanks to the advances in modern medicine that have been made. A 93% survival rate gives parents more hope when their child is first diagnosed. While there are no ways to prevent it yet, the more we learn about the causes like immature kidney cells, genetic disorders and birth defects, the better the future looks for children who suffer from Wilm's tumor.

Bibliography

Neighbors, M., Tannehill-Jones, R. (1st Ed.). (1999). Human Diseases. New York: Delmar.
Springhouse. (8^th Ed.). (2005). Professional Guide to Diseases. Lippincott, Williams & Wilkins.
Beers, M. H., MD. (18^th Ed.). (2005). Merck Manual. Merck Research Laboratories.

source:www.associatedcontent.com