Early signs of cancer in children

Childhood cancer is very rare. But as parents, it can be concerning if your child starts having unusual or unexplained symptoms.

Ka thleen Ludwig, M.D., Pediatric Hematologist/Oncologist at Children's Health℠ and Assistant Professor at UT Southwestern, shares facts about childhood cancer, early signs parents should be aware of and what to do if you're worried.

How common is cancer in children?

In the U.S., approximately 10,000 children under the age of 15 will be diagnosed with cancer in 2022. Because pediatric cancer is so rare, any symptoms your child has are much more likely to be a viral infection, injury or another common condition.

Unlike cancer in adults, the chance of your child getting cancer isn't increased by risk factors, like an unhealthy lifestyle. A strong family history of certain cancers may increase a child's risk of cancer, but these genes are extremely rare.

"When kids have cancer, it's almost always caused by a change within cells that happens spontaneously, meaning it's random," Dr. Ludwig explains. "The most common pediatric cancers are not inherited from parents or caused by anything that the parents or child did."

What are the most common cancers in children?

There are many types of pediatric cancers, but the most common are:

• Leukemia. This is the most common childhood cancer, affecting about 30% of children with cancer. It's a blood cancer that causes rapid growth of abnormal blood cells.
• Brain and nervous system cancers. These account for about 26% of childhood cancers, making them the second most common type. Most brain cancers in children begin in the lower parts of the brain.
• Lymphoma. These cancers affect the lymphatic system, including the lymph nodes. Lymphoma accounts for about 8% of childhood cancers.

What are signs of cancer in children?

The first signs of pediatric cancer vary based on the type of cancer, but many of the symptoms are very typical for kids, like bruising and a fever. So how do you identify the early signs of cancer compared to other common childhood conditions?

Dr. Ludwig says that you should watch out for symptoms that are:

• Persistent and worsening over at least a week, despite treatment
• Out of proportion to what's considered normal for your kid at their age
• Occurring in combination with other associated symptoms

Common early symptoms of leukemia

Leukemia typically presents with all three of these symptoms:

• Easy bruising, particularly in abnormal places, like on the back or stomach
• Hip or leg pain that may cause limping and isn't associated with an injury
• Unexplained fever

Your child may also have:

• Increased fatigue
• Paleness
• Sudden weight loss

Leukemia typically occurs between ages 2 to 7, but it can happen at any age.

"Because leukemia symptoms are common for kids, we're looking for three or more of these symptoms that are really unexplained, meaning they can't be attributed to an infection or injury, and they're out of the norm for your kid," Dr. Ludwig says. "For example, bruising is really common for kids, particularly on their legs, and especially when they're young or play sports, like soccer. That's why we tend to look for bruises in abnormal places, and that bruising occurs with other symptoms."

Common early symptoms of brain and nervous system cancers

For these cancers, the early signs are neurological changes, such as:

• New unsteady gait or balance problems
• Vomiting in the middle of the night or early morning, several times per week with headaches
• Sudden vision changes

"Symptoms vary based on what part of the brain has cancer, so your child or teen might not have all of these symptoms," Dr. Ludwig says. "We're typically looking for more than one of these neurological symptoms."

Common early symptoms of lymphoma

"The lymph nodes are the body's clean-up system that help you fight off infections. It's very normal for kids to have pea-sized lymph nodes around their neck, underarms and groin that get larger and smaller as viruses and other infections come and go," Dr. Ludwig says. "For a lymphoma evaluation, we're typically looking for several symptoms that are progressively getting worse despite antibiotics."

Symptoms of lymphoma can include:

• Large lymph nodes that are very hard, matted and don't move when you touch them
• Lymph nodes in the collarbone area
• Increased fatigue
• Unexplained fever
• Paleness
• Weight loss

Although lymphoma can occur at any age in kids, it's much more common during the teenage years.

What should you do if you're concerned about signs of cancer in your child?

If you're concerned about your child's symptoms, contact your pediatrician. They'll perform a physical exam. If they're concerned, they may order some tests, like a blood test. If any tests come back abnormal, they may refer your child to a specialist for further testing that can confirm a cancer diagnosis. If tests come back normal, it's likely your child's symptoms are from a viral infection or another condition.

Learn more about treating childhood cancer

Most childhood cancers are treatable, and more children are surviving cancer than ever before. About 80% of children diagnosed with cancer will survive and grow into adulthood. There are many promising treatment advances that continuously improve childhood cancer survival rates.

Learn 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.