What causes childhood cancer? A medical mystery

A cancer diagnosis in a child is frightening. Parents may have dozens of questions about their child's health, treatment and future, including – how did my child get cancer?

To understand what causes cancer in children, it's important to understand how cancer works. All cancers, including those in adults, occur when the DNA in a cell mutates or changes. The body typically kills this new cell before it can cause any damage.

However, in the case of cancer, the mutated cell keeps growing and splitting into more cells. Cancer cells grow and divide much faster than healthy cells. They can spread throughout the body, sometimes causing tumors.

What causes this mutated cell? In children, it's unclear.

Causes of childhood cancer

While researchers continue to investigate causes of childhood cancer, the exact answer remains a medical mystery.

Adults may have behaviors that put them at a higher risk for cancer, such as smoking or eating an unhealthy diet. But children are too young for any unhealthy habits to increase their risk of cancer.

A strong family history of cancer may increase a child's risk of cancer, but these genes are extremely rare. Childhood cancers are almost always caused by a DNA mutation that is not inherited but happens randomly (acquired). Children with acquired DNA mutations can't pass them on to their children in the future.

"We try to emphasize to parents that they did nothing to cause their child's cancer, and their child did nothing to cause the cancer," says Tanya Watt, M.D., pediatric oncologist at Children's Health℠ and Associate Professor at UT Southwestern. "Researchers have looked at every possible cause of childhood cancer – from what mom ate during pregnancy to the parents' jobs, to where they live. We can't come up with a reason why some children get cancer, and others do not. We hope parents understand this isn't their fault or anybody's fault."

Common childhood cancers

More than 15,000 children are diagnosed with cancer every year. Certain types of cancer are more common among children, including:

• Leukemia (blood cancer): the most common childhood cancer, affecting about 30% of children with cancer
• Brain and nervous system cancers
• Lymphoma (lymph system cancers)
• Other types of tumors, such as Wilms' tumors (kidney cancer), neuroblastoma or osteosarcoma (bone cancer)

Can kids survive cancer?

Most childhood cancers are very treatable. Approximately 80% if children diagnosed with cancer will survive and grow into adulthood. Survival rates are increasing due to major treatment advances in recent decades. Dr. Watt says children are more likely to respond well to chemotherapy and radiation therapy, leading to higher childhood cancer survival rates than adult survival rates.

To better understand your child's cancer, speak to your child's doctors openly and ask questions. It can be helpful to bring a notebook to your appointments. Write down your questions about cancer treatment for your child and the specific answers and directions from the team. This can help you keep track of the childhood cancer treatment action plan – bringing peace of mind. Remember, in stressful situations, it can be easy to forget what you've heard.

Learn more about treating childhood cancer

Learn more about the Pauline Allen Gill Center for Cancer and Blood Disorders at Children's Health and how our highly trained experts help children fight cancer.