Hearing the words “childhood cancer” can be frightening for any parent. But there is an important fact to understand first: childhood cancer is rare, and most symptoms that can occur with childhood cancer are much more likely to have another explanation.

Unlike many adult cancers, most childhood cancers cannot be traced to lifestyle choices or a known environmental exposure. There are also no routine cancer-screening tests recommended for children at average risk.

That means recognizing persistent or unusual changes and discussing them with a child’s healthcare provider can be important.

What causes childhood cancer?

Most childhood cancers have no known cause.

Cancer develops when genetic changes cause cells to grow or divide uncontrollably. In children, many of these changes occur during development and are not inherited from a parent.

The National Cancer Institute estimates that about 8% to 10% of childhood cancers are associated with inherited pathogenic genetic variants. The percentage varies depending on the type of cancer.

For most children who develop cancer, however, there is no known inherited or environmental explanation.

That also means parents should not automatically blame themselves if their child is diagnosed with cancer.

Why don’t children have routine cancer screenings?

For adults, doctors use screening tests for certain cancers because screening can detect disease before symptoms appear in people at increased risk.

For children at average risk, there are currently no routine screening tests for most childhood cancers.

Instead, childhood cancer is often discovered when a child develops symptoms or a physical change that prompts a medical evaluation. Doctors may then use blood tests, imaging, biopsies or other tests to determine what is causing the problem.

Some children with inherited cancer-predisposition conditions may require specialized surveillance. But that is different from routine screening for all children.

What warning signs should parents know?

There is no single symptom that means a child has cancer.

Possible warning signs can include:

• persistent or unusual fatigue or low energy
• unexplained weight loss or loss of appetite
• persistent bone or joint pain
• unusual bruising or bleeding
• fevers or illnesses that don’t go away
• swollen lymph nodes that persist or continue growing
• an unexplained lump or swelling
• persistent headaches, particularly when accompanied by vomiting
• changes in vision
• unexplained abdominal swelling

These symptoms can have many causes, and most children who experience them do not have cancer. The American Cancer Society emphasizes that childhood cancer symptoms are much more likely to be caused by something other than cancer.

The more important question is often whether a symptom is persistent, unusual for the child or getting worse.

A parent who notices a concerning change does not need to determine what it means. The appropriate next step is to contact the child’s healthcare provider and explain what has changed, how long it has been happening and whether other symptoms are present.

Treatment has improved survival

Childhood cancer treatment has changed dramatically over the past several decades.

Today, about 85% of children with cancer survive at least five years, although outcomes vary substantially depending on the type of cancer, the child’s age and other factors.

Five-year survival is an important measure of progress, but it should not be interpreted as a guarantee for an individual child or as meaning every child is cured within five years.

Treatment depends on the specific cancer and may include:

• chemotherapy
• surgery
• radiation therapy
• targeted therapies
• immunotherapy
• stem cell or bone marrow transplantation

Children are often treated by specialized pediatric oncology teams that bring together physicians and other healthcare professionals with expertise in childhood cancers.

Surviving cancer can bring another set of health needs

Better survival has created another important part of pediatric cancer care: survivorship.

Some cancer treatments can produce health effects months or years after treatment ends. Depending on the cancer and treatment received, survivors may face problems involving the heart, bones, endocrine system, fertility, cognition or other aspects of health.

That is why long-term follow-up can remain important even after cancer treatment is complete. The National Cancer Institute maintains specific guidance on monitoring and managing these potential late effects.

Survivorship care is not necessarily a sign that cancer has returned. It is part of helping survivors maintain their health as they grow older.

What parents should take away

The most important message is not to become alarmed by every fever, bruise or period of tiredness.

Children experience many ordinary illnesses and symptoms. Most are not cancer.

Instead, parents should pay attention when something doesn’t seem to resolve normally, keeps returning, becomes more severe or is accompanied by other unexplained changes.

When that happens, a pediatrician or other healthcare professional can determine whether further evaluation is needed.

There is also an important message for parents of children who do develop cancer:

In most cases, there is no evidence that a parent’s choices caused the disease.

Childhood cancer is usually not the result of a child eating the wrong foods, failing to exercise or a parent missing some simple preventive step.

Childhood cancer is rare, and there is no routine screening program for most children at average risk.

That makes awareness of persistent or unusual symptoms important—but awareness should not become fear.

Most childhood symptoms have ordinary explanations.

The goal is simply to recognize when something is persistent, unexplained or different enough to deserve medical attention.

And when childhood cancer does occur, advances in treatment mean that the majority of children diagnosed today survive at least five years, while ongoing research continues to improve treatment and survivorship care.

For parents, the most useful approach is straightforward:

Know your child’s normal. Pay attention when something changes. And when a symptom doesn’t make sense or doesn’t go away, ask the child’s healthcare provider about it.