Childhood Cancer: An Overview

Pediatric cancer refers to cancers diagnosed in infants, children (up to age 14), and teenagers (ages 15–19). While rare, childhood cancers are often treatable, and many young patients survive for five years or more after diagnosis.

A Frightening Thought: "Could my child have cancer?"

Childhood cancers differ significantly from adult cancers—not only in how they develop but also in how they respond to treatment. The most common pediatric cancers include leukemia, tumors of the brain and spinal cord, lymphomas, neuroblastoma, Wilms tumor (kidney cancer), retinoblastoma, and bone or soft tissue cancers.

Warning Signs (C.H.I.L.D.R.E.N):

• C – Continuous, unexplained weight loss
• H – Headaches with morning vomiting or nausea
• I – Increased swelling or ongoing pain in bones, joints, back, or legs
• L – Lumps or masses in areas like the abdomen, neck, chest, pelvis, or armpits
• D – Development of a whitish color in the pupil or changes in vision
• R – Repeated fevers or infections not linked to other illnesses
• E – Excessive bruising or unexpected bleeding
• N – Noticeable paleness and constant fatigue

Types of Childhood Cancer:

Unlike adult cancers—which usually begin in organs—childhood cancers often arise in tissues like blood, the lymphatic system, muscles, bones, or the central nervous system.

Blood Cancers:

• Leukemia: The most common type is acute lymphoblastic leukemia (ALL), where the bone marrow produces an excess of immature white blood cells. This cancer can impact red cells, white cells, and platelets.
• Lymphoma: This cancer starts in the lymphatic system. The two main forms are Hodgkin lymphoma (high cure rate) and Non-Hodgkin lymphoma (NHL).

Brain Tumors:

Brain and spinal cord tumors are the most common types of cancer in children. While some are non-cancerous, many can be treated successfully.

Bone Cancers:

Though rare, bone cancers such as osteosarcoma and Ewing sarcoma often occur in children and teenagers.

Neuroblastoma:

This cancer forms from immature nerve cells and most commonly affects young children.

Wilms’ Tumor:

A kidney cancer seen mostly in children between the ages of two and four. It has a high cure rate when diagnosed early.

Rhabdomyosarcoma:

The most common soft tissue cancer in children, beginning in muscles that help move the body.

Retinoblastoma:

A rare cancer of the retina, mostly found in children under the age of 5. Early diagnosis allows for successful treatment.

Signs and Symptoms of Retinoblastoma:

• Crossed eyes (squint)
• Change in iris color
• Redness or swelling in the eye
• Poor or declining vision
• One common symptom is an unusual white reflection in the pupil, resembling a cat’s eye in photographs.

A Growing Global Concern

Every year, around 400,000 children and teens (ages 0–19) are diagnosed with cancer, and this number is steadily increasing.

Understanding the Causes

Cancer begins when genetic changes in a single cell cause it to grow uncontrollably.

In Children:

Unlike adult cancers, most childhood cancers don’t have a known cause.

Types of Genetic Changes:

• Acquired Mutations: The most common causes of childhood cancer. These are not inherited.
• Inherited Mutations: A smaller percentage (8–10%) of childhood cancers result from inherited genetic mutations.
  • Examples: Mutations in the RB1 gene (retinoblastoma), or syndromes like Li-Fraumeni syndrome and Down syndrome.
• Mutations During Early Development: Rarely, genetic changes may occur during the formation of a child’s first cells.

Environmental Exposures:

Some environmental agents—like cigarette smoke, asbestos, and UV rays—can damage DNA. While a definitive link is difficult to establish, research has identified a few potential connections:

• Melanoma in older children shows genetic similarities to adult melanoma, including mutations caused by UV radiation.
• Ionizing radiation from historical events (atomic bombings, Chernobyl) or medical procedures (x-rays, CT scans) has been associated with a slight increase in the risk of childhood leukemia and other cancers.
• Parental exposures (e.g., paternal smoking, parental workplace exposure to pesticides) have been linked to certain leukemias.
• Some studies suggest a potential link between maternal consumption of cured meats during pregnancy and an increased risk of childhood brain tumors.

Exposure to Infections

The Epstein-Barr virus (EBV) has been associated with cancers such as Hodgkin lymphoma and Burkitt lymphoma in rare cases.

Radiation from Cancer Treatment

Ironically, radiotherapy, a common treatment for childhood cancer, can slightly raise the risk of developing a second cancer later in life.

Previous Cancer Treatments and Risk Factors

Children who’ve undergone chemotherapy may face an increased risk of developing secondary cancers later in life.

Common Risk Factors for Childhood Cancer:

• Exposure to radiation
• Secondhand smoke
• Inherited genetic syndromes
• Birth defects
• Chemical exposure
• Prior cancer history
• Certain infections
• Environmental factors
• Diet
• Pre-existing medical conditions

“The desperate question: Then how do I save my child?”

Improving Childhood Cancer Outcomes

Since most childhood cancers cannot be prevented, the best way to reduce their impact is through early, accurate diagnosis followed by effective treatment and targeted supportive care.

Importance of Early Diagnosis

Early detection leads to better survival rates and less aggressive therapies.

Three Key Steps in Early Diagnosis:

1. Awareness – Families and healthcare providers must recognize early symptoms.
2. Accurate Evaluation – Timely diagnosis and staging.
3. Immediate Access to Treatment – Prompt action once cancer is identified.

Treatment of Childhood Cancer

A correct diagnosis is essential for determining the best treatment plan. When treatment is accessible, over 80% of children with cancer can be cured.

Key Treatment Options

1. Surgery: Used to remove tumors or take samples for biopsy.
2. Radiation Therapy: Uses high-energy beams to kill cancer cells.
3. Chemotherapy and Other Drugs: Chemotherapy destroys rapidly dividing cells. Other drugs include targeted therapy and immunotherapy.
4. Stem Cell Transplant (Bone Marrow Transplant): Allows delivery of high-dose treatments by replenishing damaged blood cells.

Immunotherapy

Immunotherapy harnesses the body’s own immune system to detect and destroy cancer cells. It is increasingly being used in pediatric cancers.

Screening

Routine screening is generally not effective for childhood cancers due to their rarity. Screening may be considered for children with hereditary risks.

Diagnostic Tests for Childhood Cancer

A combination of tests may be used:

• Blood tests
• Biopsy
• Bone marrow aspiration and biopsy
• Lumbar puncture (spinal tap)
• Ultrasound
• CT scan
• MRI scan
• PET scan

Clinical Trials in Pediatric Cancer

Most children are treated in specialized cancer centers that offer access to clinical trials. Advances in pediatric cancer survival are largely due to these trials.

Managing Side Effects & Palliative Care

Side effects vary based on the type and intensity of treatment. Palliative care is vital, focusing on:

• Easing symptoms
• Managing treatment side effects
• Supporting emotional and mental well-being

Palliative Care in Childhood Cancer

Palliative care focuses on relieving symptoms and improving quality of life for children and their families. It should begin at diagnosis and continue throughout treatment.

Late Effects of Treatment

Childhood cancer survivors may face long-term effects, called late effects, which require ongoing follow-up care.

Common Late Effects:

• Impaired growth and development
• Neurocognitive and psychosocial challenges
• Heart and lung problems
• Endocrine issues
• Digestive disorders
• Risk of secondary cancers

Outlook & Prognosis

• What are the survival rates? Survival varies by cancer type. For example, 5-year survival rates are 99% for Hodgkin lymphoma and 88% for leukemias in children.
• Are most childhood cancers curable? Yes. According to the WHO, over 80% of children with cancer are cured.

Living with Childhood Cancer

• How can I support my child? Talk to a child life specialist, join survivorship programs, and encourage normal routines when possible.
• When should I seek medical care? Contact your child’s healthcare provider if you notice unexpected side effects or new symptoms.
• When is it an emergency? Your provider will tell you what warning signs require immediate emergency care.

Frequently Asked Questions (FAQs) About Childhood Cancer

1. Is cancer contagious? No. Cancer is not an infectious disease.
2. Did the child do something to cause cancer? No. The exact causes are often unknown, and it is not a result of anything a child or family did.
3. Is all cancer the same? No. Childhood cancers differ from adult cancers, and each type develops in different cells.
4. Why does cancer treatment cause hair loss and sickness? These are side effects of treatments like chemotherapy, which usually go away once treatment ends.
5. Can cancer affect emotions as well as the body? Yes. Emotional stress is common, and support and open communication are very important.
6. Can a child with cancer still go to school? Often, yes. Many children can keep up with schoolwork and return to school once their health allows.
7. Should children with cancer be treated differently by others? No. They usually want to be treated like everyone else.
8. Should we talk about cancer with children? Yes. Honest and age-appropriate conversations are helpful, and it is important to respect the child’s comfort level.