What Is Cancer?

Every cell in the body has a system that controls how it grows, how it interacts with other cells, and how long it lives. Sometimes, cells lose that control and grow in a way that the body can no longer control. This is called cancer.

There are different kinds of cancer, but they develop in the same way as the cells:

• grow out of control
• develop unusual sizes and shapes
• move past their usual boundaries inside the body
• destroy nearby cells

As cancer cells grow, they can make a person weaker, harm organs and bones, and make it hard for the body to fight off other illnesses.

What Is Pediatric Cancer?

Cancer is uncommon in children, but can happen. The most common childhood cancers are:

• leukemia. The most common cancer in children is acute lymphocytic leukemia (ALL).
• lymphoma
• brain cancer
• in teens, osteosarcoma (bone cancer) 

Pediatric, or childhood, cancers and how they're treated have important differences from cancers that adults get, such as:

• The things that cause cancer in kids usually differ from those that cause cancer in adults (for example, smoking).
• Kids usually respond well to treatment. Most kids with cancer get better.
• Side effects of cancer treatments can be more severe and longer lasting. Children who have had cancer will need careful medical follow-up for the rest of their lives.

Why Do Kids Get Cancer?

Most of the time, doctors don't know why kids get cancer. In children, a genetic condition, such as Down syndrome, can sometimes increase the risk of cancer. Kids who have had chemotherapy or radiation treatment for cancer are more likely to get cancer again.

But most cases of childhood cancer happen because of random mutations (changes) in the genes of growing cells. Because these changes happen randomly, there is no effective way to prevent them.

How Is Cancer Treated?

Getting treatment at a medical center that specializes in pediatric oncology (treatment of childhood cancer) can help kids with cancer get the best care.

The treatment of cancer in children can include:

• surgery: removing cancerous cells or tumors
• chemotherapy: using medical drugs to kill cancer cells
• radiation therapy: using radiant energy to kill cancer cells
• bone marrow (stem cell) transplant: putting healthy stem cells into the bloodstream so they can make healthy new blood, bone marrow, and immune system cells

Doctors may use one or more of these treatments for a child who has cancer. The type of treatment needed depends on the child's age, the type of cancer, and how severe the cancer is.

How Can Parents Help?

The main goal when treating kids with cancer is to cure them. While treatment may cause side effects, many medicines and therapies can make kids more comfortable while they're treated for cancer.

When possible, involve kids with their own cancer treatment. Use language your child will understand and explain the facts about the cancer and its effects. With a younger child — toddlers and those younger than age 4 — saying that they are "sick" and need "medicine" to get better can be enough of an explanation. For all age groups, the goal is to prevent fear and misunderstanding.

Many kids might feel guilty, as if the cancer is somehow their fault. Psychologists, social workers, and other members of the cancer treatment team can be a great help in reassuring them and helping them cope with their feelings.

Having a child being treated for cancer can feel overwhelming for any family. But you're not alone. To find support, talk to anyone on the care team or a hospital social worker. Many resources are available to help you and your child.

You also can find information and support online at: