Most Common Childhood Cancers: Signs Every Parent Should Know

The most common childhood cancers include leukaemia, brain and spinal cord tumours, neuroblastoma, Wilms tumour, and lymphoma.

A child doesn’t always say, ‘Something is wrong.’ Sometimes the signs are small changes that a parent notices first. Childhood cancer is rare compared to cancer in adults, but early recognition of symptoms of cancer in children can improve treatment outcomes.

This guide covers the most common childhood cancers, their early signs, and the symptoms parents should watch for.

Why Early Recognition of Childhood Cancer Symptoms Matters?

Unlike adult cancers, childhood cancers are rarely linked to lifestyle or environmental risk factors. This makes symptom awareness the most practical early-detection tool available to parents.

A persistent symptom is one that:

• Lasts longer than two to three weeks
• Does not improve with standard treatment (antibiotics, rest, or over-the-counter medication)
• Is accompanied by fatigue or recurring fever

Leukaemia: The Most Common Childhood Cancer

Leukaemia accounts for the largest share of childhood cancers and often presents with fatigue, bruising, bone pain, and recurrent infections.

Leukaemia begins in the bone marrow and affects the body’s ability to produce healthy blood cells. Because the symptoms build gradually, they are frequently mistaken for viral infections or growing pains.

Key Signs to Watch For

• Persistent fatigue or paleness that does not improve with rest
• Frequent nosebleeds or bleeding gums
• Unexplained bruising, especially in areas not prone to injury
• Bone or joint pain, sometimes causing a limp in younger children
• Recurrent fevers or infections that do not respond to standard treatment
• Swollen lymph nodes in the neck, underarm, or groin

Read More – Early Signs of Leukaemia in Children: Symptoms Parents Should Never Ignore

Brain and Spinal Cord Tumours

Brain tumours in children often present with morning headaches, vomiting without nausea, and changes in balance or vision rather than a single dramatic symptom.

These are the second most common group of childhood cancers after leukaemia. Symptoms vary widely depending on the tumour’s location.

Signs by Age Group

In infants and toddlers:

• An unusually rapid increase in head size
• Bulging soft spot (fontanelle)
• Loss of previously achieved developmental milestones

In older children:

• Persistent or worsening headaches, particularly in the morning
• Repeated vomiting without an obvious cause
• Problems with balance or coordination
• Changes in vision
• Seizures
• Changes in behaviour, concentration or school performance

Neuroblastoma

Neuroblastoma most commonly develops in the adrenal glands or abdomen and often first appears as a firm, painless lump felt during a routine check.

This cancer typically affects children under five years old and originates in immature nerve cells.

Signs to Watch For

• A firm lump in the abdomen, neck, or chest
• Bulging eyes or dark circles around the eyes
• Bone pain or a limp
• Unexplained fever unrelated to infection
• Diarrhoea or high blood pressure caused by hormone-secreting tumours

Read more about neuroblastoma diagnosis and staging

Wilms Tumour (Kidney Cancer)

Wilms tumour usually presents as a painless abdominal swelling that a parent notices while bathing or dressing the child, often before the child shows any other symptoms.

This kidney cancer typically affects children between two and five years of age and is one of the more treatable solid tumours in paediatric oncology.

Signs to Watch For

• A firm swelling or mass on one side of the abdomen
• Blood in the urine
• High blood pressure
• Loss of appetite and unexplained weight loss
• Fever without an identifiable infection

Learn more about Wilms tumour treatment.

Lymphoma (Hodgkin and Non-Hodgkin)

Lymphoma typically presents with painless, persistent swelling of the lymph nodes in the neck, chest, or abdomen, often alongside night sweats and unexplained weight loss.

Lymphomas originate in the lymphatic system and are broadly classified as Hodgkin or non-Hodgkin lymphoma, each with different patterns of spread and treatment protocols.

Signs to Watch For

• Painless, swollen lymph nodes that persist beyond two to three weeks
• Persistent cough or breathing difficulty, if nodes press on the airway
• Night sweats
• Unexplained fever
• Fatigue and loss of appetite

See our detailed guide to lymphoma in children.

A Note for Parents

Sometimes, the first sign that something is wrong is simply that your child seems different – more tired, less playful, losing weight, or just not quite themselves. You don’t need to know what the symptom means. If something feels unusual, persistent, or out of pattern for your child, don’t ignore that instinct. You know your child. And sometimes, paying attention to the small changes is the most important thing you can do.

Expert Insight – Most symptoms of childhood cancer overlap with common childhood illnesses. This is exactly why parents should trust their instinct when something feels out of pattern.” – Dr. Satyendra Katewa 

Most childhood symptoms might not be cancer, but when something doesn’t feel right, asking the question is always worth it.