Late Effects of Childhood Cancer and Its Treatment

Treatment of childhood blood cancer may consist of chemotherapy, other drug therapies, radiation therapy, or allogeneic stem cell transplantation.

Long-term and late effects common to these treatments may include:

• Physical effects
  • Learning difficulties 
  • Fatigue
  • Bone/joint pain
  • Growth delays (due to growth hormone deficiency)
  • Thyroid dysfunction (hypothyroidism or hyperthyroidism)
  • Hearing loss
  • Obesity
  • Increased risk of secondary cancer
  • Heart conditions/damage (chronic heart failure, heart muscle injury, and weakness of the heart muscle)
  • Lung damage (scarring, inflammation, acute respiratory distress syndrome, or lung failure)
  • Peripheral neuropathy
  • Dental abnormalities
  • Digestive issues (chronic abdominal pain and diarrhea)
  • Vision problems (cataract or glaucoma)
  • Osteoporosis (low bone density)
  • Decreased fertility (in adulthood)
  • Amputations (eye removal, disfigurement)
  • Organ system damage
• Psychological effects
  • Changes in mood, feelings, or behavior
  • Depression 
  • Post-traumatic stress disorder
  • Low self-esteem
  • Poor adjustment
  • Deteriorating quality of life
• Cognitive effects
  • Decreased problem-solving skills
  • Reduced attention span
  • Reduction in skills such as reading and spelling, processing of information, planning, and organizing
  • Decreased concentration levels
  • Issues with fine motor coordination skills (poor handwriting)
  • Lower IQ scores
  • Problems with memory 
  • The decline in academic achievement test scores
• Emotional effects
  • Constant worry or fear about the development of new health problems or cancer relapse
  • Anxiety
  • Feelings of resentment
  • Concerns about being discriminated against (by friends, classmates, coworkers, or employers)
  • Concerns about dating, marrying, and having a family later in life

Cancer treatments may vary from child to child and from one type of cancer to another. However, the risk of long-term or late effects can be influenced by three factors:

1. Tumor-related factors
   • Type of cancer
   • Location of the cancer
   • The extent of the tumor (affecting the functions of tissues and organs)
2. Treatment-related factors
   • Treatment’s type and duration
   • Type of surgery
   • Chemotherapy dose and schedule
   • Radiation therapy dose and part of the body treated
   • Simultaneous use of two or more types of treatment
   • Chronic graft-versus-host disease
3. Patient-related factors
   • Age of the child at the time of diagnosis and treatment
   • Gender of the child
   • The overall health of the child
   • Changes in hormone levels
   • Socioeconomic status
     • Health habits
     • Child’s genetic makeup (inherited risk or familial history of certain health problems)

Leukemia is a type of blood cell cancer that most commonly affects children and teenagers (accounting for one out of three cancers).

Leukemia typically starts in the bone marrow, from where it can spread to the bloodstream. Certain types of leukemia can spread to other parts of the body including the lymph nodes, liver, spleen, central nervous system (the brain and spinal cord), and testicles.

1. Acute leukemias
   • Because these leukemias can progress and worsen quickly, they require aggressive and immediate treatment.
   • Acute leukemia is further divided into the following:
     • Acute lymphocytic (lymphoblastic) leukemia (ALL): Typically originates in early forms of lymphocytes (white blood cells). ALL accounts for three out of every four childhood leukemias.
     • Acute myeloid leukemia (AML): A type of acute leukemia that can disrupt the production of normal white blood cells, red blood cells, and platelets. Also known as acute myelogenous leukemia, acute myelocytic leukemia, or acute nonlymphocytic leukemia.
     • Acute undifferentiated leukemia: This is a rare type of acute leukemia that does not have lymphoid or myeloid cell-specific markers. 
2. Chronic leukemias
   • Tend to grow slowly and are harder to cure. 
   • Chronic leukemias can be further divided into two types:
     • Chronic myeloid leukemia (CML): Also known as chronic myelogenous leukemia
     • Chronic lymphocytic leukemia: Rarely found in children
3. Juvenile myelomonocytic leukemias
   • A rare type of leukemia (neither chronic nor acute), which starts in myeloid cells but usually doesn’t grow as fast as AML or as slow as CML.
   • Most often found in young children with an average age of two years.

Some of the known risk factors for childhood cancer include:

• Having a sibling with leukemia
• Genetic syndromes
  • Down syndrome 
  • Li-Fraumeni syndrome 
• Inherited immune system problems
  • Ataxia-telangiectasia
  • Wiskott-Aldrich syndrome
  • Bloom syndrome
  • Shwachman-Diamond syndrome
• Lifestyle-related factors (excessive alcohol consumption during pregnancy)
• Environmental factors (radiation and certain chemicals)
• Exposure to chemotherapy
• Immune system suppression (organ transplants)
• Exposure to electromagnetic fields 
• Residing near a nuclear power plant
• Viral infections early in life
• Age of mothers at the time of childbirth
• Parental history of smoking
• Fetal exposure to hormones (such as diethylstilbestrol)
• Paternal occupational exposure to toxins, chemicals, and solvents
• Chemical contamination of groundwater

The prognosis of childhood leukemia depends on certain factors such as the age at diagnosis, gender, chromosomal changes, type, extent, and spread of the disease, and initial response to the treatment.

• The five-year survival rate of children aged 0 to 14 years diagnosed with acute lymphocytic leukemia has increased to 90 percent with early diagnosis and appropriate treatment.
• However, children younger than 15 years with acute myeloid leukemia have a five-year survival rate of 68 percent.