Kidney cancer is a condition in which tumors begin developing in the kidneys. While it is typically more common in adults, some rare types of kidney cancer occur more frequently in children.

Kidney cancer, also known as renal cancer, is cancer involving the kidneys. It is one of the more common types of cancer, with the National Cancer Institute estimating that doctors will diagnose roughly 79,000 new cases in 2022.

However, there are many different types of kidney cancer. Despite it being very uncommon in people under the age of 45 years, certain types can affect children.

Childhood kidney cancers account for roughly 7% of all childhood cancer, with Wilms’ tumor being the most common type. Each year, there are about 500–600 new cases of Wilms’ tumor in the United States.

While it remains unknown why some kidney cancers develop during childhood, many typically relate to genetic alterations.

In this article, we will discuss childhood kidney cancer, including types, symptoms, causes, and treatments.

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Childhood kidney cancer refers to when cancer develops in the kidneys. The kidneys help filter the waste, toxins, and excess water that naturally build up within the blood.

When kidney cells begin to grow and divide uncontrollably, this can impact their function and lead to the development of tumors.

While the risk of cancer tends to increase with age, and childhood kidney cancer is very rare, it is still possible for renal tumors to develop in children. According to a 2022 study, around 6% of all childhood cancers are kidney cancers.

There are many types of childhood kidney tumors, such as:

  • Wilms’ tumor
  • renal cell carcinoma
  • rhabdoid tumor of the kidney
  • clear cell sarcoma of the kidney
  • congenital mesoblastic nephroma
  • Ewing sarcoma of the kidney
  • primary renal myoepithelial carcinoma
  • cystic partially differentiated nephroblastoma
  • multilocular cystic nephroma
  • primary renal synovial sarcoma
  • anaplastic sarcoma of the kidney

Researchers are still unsure about the exact cause of childhood kidney cancer. However, evidence suggests that changes in certain genes may increase the likelihood of developing renal tumors.

Certain conditions or environmental exposures may further increase a child’s risk. As such, a doctor may suggest genetic counseling if a child has certain syndromes or conditions.

For example, Wilms’ tumor is the most common type of childhood kidney cancer, with evidence suggesting that about 9 in 10 kidney cancers in children are Wilms’ tumors.

Many underlying conditions or genetic changes may increase the risk of uncontrolled cell growth, resulting in immature kidney cells clustering into a mass, leading to a tumor in the kidney.

There is a strong genetic component to the development of Wilms’ tumor. Evidence notes that in roughly 99% of cases, one of the child’s parents also has the condition.

Moreover, research notes that gene alterations, such as SMARCB1, TFE, NTRK3, and ETV6, can result in the development of other, rarer renal tumors in children.

According to a 2018 study, there are several common symptoms of kidney cancer in children. The symptoms can include:

To reach a diagnosis, a doctor will complete a medical history and perform a physical examination of the child.

If they suspect kidney cancer, they may order additional tests to help determine whether it is cancer and whether it has spread to other parts of the body.

The tests the doctor may order include:

There are different types of treatments available for children with kidney tumors. A doctor will consider the type and stage of cancer when deciding on a treatment plan.

A pediatric oncologist — a doctor who specializes in treating children with cancer — will oversee the treatment and lead a team that may consist of specialists such as pediatricians, pediatric surgeons, and pediatric urologists.

Treatment options may include:

There is no single prognosis for childhood kidney cancer. The outlook changes with the specific form of the cancer that an individual might have, although it does tend to be quite positive.

Similar to other types of cancer, the earlier a person receives a diagnosis and begins treatment, the better the prognosis.

For example, for Wilms’ tumor, the overall survival rate may be as high as 86–99%, although in some individuals, it can be as low as 38–84%.

For congenital mesoblastic nephroma, a 2015 study notes that the 5-year survival and overall survival rates of infants are 94% and 96%, respectively.

Childhood kidney cancer refers to a rare group of renal cancers that affect children. There are many different types of kidney cancers that can develop during childhood, with Wilms’ tumor being the most common.

Researchers are still unsure as to the exact cause of these cancers. They understand, however, that genetics plays a role.

If a pediatrician suspects kidney cancer, they can perform tests to help identify and stage the cancer.

There are different treatment options available, such as nephrectomy, which is surgery to remove the kidney.

Generally, the outlook for childhood kidney cancer is rather positive.