Leukemia

A group of blood cancers that affect white blood cell production in the bone marrow

Quick Facts

  • Type: Blood Cancer
  • ICD-10: C91-C95
  • New Cases: ~60,000/year in US
  • 5-Year Survival: ~65% overall

Overview

Leukemia is a type of cancer that affects the blood and bone marrow, the spongy tissue inside bones where blood cells are made. The disease occurs when the body produces large numbers of abnormal white blood cells that don't function properly. These abnormal cells crowd out healthy blood cells, leading to serious health problems.

Unlike many cancers that form solid tumors, leukemia is a "liquid" cancer that affects the blood-forming tissues. The abnormal white blood cells, called leukemia cells or blasts, accumulate in the bone marrow and blood, interfering with the production and function of normal blood cells. This disruption affects the body's ability to fight infections, control bleeding, and deliver oxygen to tissues.

Leukemia is classified into four main types based on how quickly the disease progresses (acute or chronic) and which type of white blood cell is affected (lymphoid or myeloid). Each type has different characteristics, treatment approaches, and prognoses. While leukemia can occur at any age, certain types are more common in children, while others primarily affect adults.

Symptoms

Leukemia symptoms vary depending on the type and stage of the disease. Many symptoms result from the shortage of normal blood cells and can be similar to other, less serious conditions. Some people may have no symptoms in early stages, especially with chronic forms.

Common General Symptoms

Blood-Related Symptoms

  • Easy bruising or bleeding
  • Frequent nosebleeds
  • Tiny red spots on skin (petechiae)
  • Prolonged bleeding from small cuts
  • Heavy menstrual periods
  • Bleeding gums

Infection-Related Symptoms

  • Frequent or severe infections
  • Infections that don't respond well to treatment
  • Recurring pneumonia or bronchitis
  • Persistent sore throat
  • Skin infections

Other Common Symptoms

  • Swollen lymph nodes (neck, armpit, groin)
  • Enlarged spleen or liver (fullness below ribs)
  • Unintentional weight loss
  • Night sweats
  • Shortness of breath
  • Pale skin
  • Headaches
  • Vision problems

Type-Specific Symptoms

Acute Leukemia: Symptoms appear suddenly and worsen quickly

  • Severe fatigue and weakness
  • Significant bleeding problems
  • High fever
  • Rapid weight loss

Chronic Leukemia: May have few or no symptoms for years

  • Mild fatigue
  • Feeling full after eating small amounts
  • Gradual weight loss
  • Mild fever

Causes

The exact cause of leukemia is not fully understood, but it develops when blood cells acquire mutations in their DNA. These genetic changes cause cells to grow and divide rapidly and to continue living when normal cells would die.

How Leukemia Develops

  1. DNA Mutations: Changes occur in the genetic material of blood cells
  2. Abnormal Cell Growth: Mutated cells multiply uncontrollably
  3. Crowding Effect: Abnormal cells crowd out healthy cells
  4. Impaired Function: Body cannot produce enough normal blood cells

Known Contributing Factors

Genetic Factors

  • Inherited genetic disorders (Down syndrome, Fanconi anemia)
  • Family history of leukemia (slight increased risk)
  • Genetic syndromes (Li-Fraumeni syndrome, neurofibromatosis)
  • Chromosomal abnormalities

Environmental Exposures

  • Radiation: High doses from atomic bombs, radiation therapy
  • Chemicals: Benzene, formaldehyde, pesticides
  • Chemotherapy: Previous cancer treatment
  • Smoking: Increases risk of acute myeloid leukemia

Other Medical Conditions

  • Myelodysplastic syndromes
  • Myeloproliferative disorders
  • Certain blood disorders
  • Some viral infections (HTLV-1, rare)

Types of Genetic Changes

  • Philadelphia chromosome: Found in most CML cases
  • Translocations: Pieces of chromosomes switch places
  • Deletions: Parts of chromosomes are missing
  • Mutations: Changes in specific genes (FLT3, NPM1, others)

Important Note

Most people with known risk factors don't develop leukemia, and many people with leukemia have no known risk factors. The disease is not contagious and cannot be spread from person to person.

Risk Factors

Several factors may increase the risk of developing leukemia, though having risk factors doesn't mean you will develop the disease. Risk factors vary by leukemia type.

Age-Related Risk

  • Acute Lymphoblastic Leukemia (ALL): Most common in children under 5
  • Acute Myeloid Leukemia (AML): Risk increases with age, average age 68
  • Chronic Lymphocytic Leukemia (CLL): Rare before age 40, average age 70
  • Chronic Myeloid Leukemia (CML): Most common in adults 50-60

Previous Cancer Treatment

  • Chemotherapy drugs (alkylating agents, topoisomerase inhibitors)
  • Radiation therapy, especially to bone marrow
  • Risk highest 5-10 years after treatment
  • Combined chemotherapy and radiation increases risk

Genetic Disorders

  • Down syndrome (20x higher risk of leukemia)
  • Fanconi anemia
  • Bloom syndrome
  • Ataxia-telangiectasia
  • Neurofibromatosis type 1
  • Shwachman-Diamond syndrome

Environmental and Occupational

  • Benzene exposure: Industrial solvent, gasoline
  • High radiation: Nuclear accidents, atomic bombs
  • Pesticides: Some agricultural chemicals
  • Formaldehyde: Industrial and household products
  • Hair dyes: Older formulations (pre-1980s)

Other Risk Factors

  • Smoking: Particularly for AML
  • Family history: Slight increased risk
  • Blood disorders: Myelodysplastic syndromes
  • Immune suppression: Organ transplant recipients
  • Gender: Slightly more common in males

Factors Being Studied

  • Electromagnetic fields
  • Cell phone use
  • Dietary factors
  • Infectious agents

Diagnosis

Diagnosing leukemia involves several tests to confirm the presence of cancer cells, determine the type of leukemia, and assess how far it has spread. Early and accurate diagnosis is crucial for appropriate treatment.

Initial Evaluation

  • Medical history: Symptoms, duration, risk factors
  • Physical exam: Check for swollen lymph nodes, spleen, liver
  • Vital signs: Temperature, blood pressure, heart rate

Blood Tests

Complete Blood Count (CBC)

  • Measures levels of different blood cells
  • Often shows abnormal white blood cell counts
  • May show low red blood cells (anemia)
  • May show low platelets (thrombocytopenia)

Blood Smear

  • Microscopic examination of blood cells
  • Looks for abnormal cell appearance
  • Identifies blast cells (immature cells)

Bone Marrow Tests

Bone Marrow Aspiration and Biopsy

  • Definitive test for leukemia diagnosis
  • Usually taken from hip bone
  • Examines cells and bone marrow structure
  • Determines percentage of blast cells

Specialized Tests

Flow Cytometry

  • Identifies specific proteins on cell surfaces
  • Helps classify leukemia type
  • Important for treatment planning

Cytogenetic Analysis

  • Examines chromosomes in cancer cells
  • Identifies genetic abnormalities
  • Helps predict prognosis
  • Guides targeted therapy choices

Molecular Testing

  • PCR tests for specific gene mutations
  • FISH (fluorescence in situ hybridization)
  • Next-generation sequencing
  • Minimal residual disease testing

Additional Tests

  • Lumbar puncture: Checks for leukemia in spinal fluid
  • Imaging tests: CT, MRI, PET scans for organ involvement
  • Chest X-ray: Checks for enlarged lymph nodes
  • Liver function tests: Assess organ function
  • Kidney function tests: Important for treatment planning

Classification Systems

  • FAB classification: Based on cell appearance
  • WHO classification: Incorporates genetic information
  • Risk stratification: Guides treatment intensity

Treatment Options

Leukemia treatment depends on many factors including the type of leukemia, age, overall health, and whether the cancer has spread. Treatment has improved significantly, with many people achieving remission or cure.

Chemotherapy

The primary treatment for most leukemias:

  • Induction therapy: Initial intensive treatment to achieve remission
  • Consolidation therapy: Eliminates remaining cancer cells
  • Maintenance therapy: Prevents relapse (mainly in ALL)
  • Given intravenously, orally, or intrathecally (spinal fluid)
  • Often uses combination of multiple drugs

Targeted Therapy

Drugs that target specific features of cancer cells:

  • Tyrosine kinase inhibitors: For CML and some ALL (imatinib, dasatinib)
  • Monoclonal antibodies: Target surface proteins (rituximab, blinatumomab)
  • FLT3 inhibitors: For AML with FLT3 mutations
  • IDH inhibitors: For AML with IDH mutations
  • Often combined with chemotherapy

Immunotherapy

  • CAR T-cell therapy: Genetically modified immune cells
  • Checkpoint inhibitors: Help immune system recognize cancer
  • Bispecific antibodies: Connect immune cells to cancer cells
  • Particularly effective in some relapsed cases

Stem Cell Transplant

Replaces diseased bone marrow with healthy cells:

  • Allogeneic transplant: From a donor
  • Autologous transplant: Patient's own cells (less common)
  • Requires high-dose chemotherapy first
  • Best chance for cure in many cases
  • Significant risks and side effects

Radiation Therapy

  • Used to target specific areas (brain, spleen)
  • Total body irradiation before transplant
  • Treat leukemia in nervous system
  • Shrink enlarged organs

Supportive Care

  • Blood transfusions: Red blood cells, platelets
  • Antibiotics: Prevent or treat infections
  • Growth factors: Stimulate blood cell production
  • Anti-nausea medications: Manage side effects
  • Pain management: As needed
  • Nutritional support: Maintain strength

Treatment by Type

Acute Leukemias (ALL, AML)

  • Requires immediate treatment
  • Intensive chemotherapy phases
  • May need transplant for cure
  • CNS prophylaxis important

Chronic Leukemias (CLL, CML)

  • May watch and wait initially (CLL)
  • Targeted therapy often first-line
  • Less intensive treatment
  • Long-term management approach

Prevention

Most cases of leukemia cannot be prevented because the causes are not fully understood or controllable. However, some risk factors can be avoided or minimized.

Lifestyle Modifications

  • Don't smoke: Reduces risk of AML
  • Maintain healthy weight: May reduce overall cancer risk
  • Eat a balanced diet: Rich in fruits and vegetables
  • Exercise regularly: Supports immune system
  • Limit alcohol: May reduce overall cancer risk

Chemical Exposure Prevention

  • Avoid benzene: Use protective equipment if exposed at work
  • Limit pesticide exposure: Use alternatives when possible
  • Follow safety guidelines: For chemical handling
  • Proper ventilation: When using solvents or chemicals
  • Regular monitoring: If occupationally exposed

Radiation Protection

  • Minimize unnecessary medical radiation
  • Use protective equipment when required
  • Follow safety protocols in radiation areas
  • Consider risks vs benefits of imaging tests

For High-Risk Individuals

  • Genetic counseling: If family history of cancer
  • Regular monitoring: If genetic syndrome present
  • Avoid additional risks: Such as smoking or chemical exposure
  • Follow-up care: After cancer treatment

Secondary Prevention

For cancer survivors at risk of treatment-related leukemia:

  • Regular blood count monitoring
  • Report unusual symptoms promptly
  • Long-term follow-up care
  • Awareness of warning signs

Research and Future Prevention

  • Ongoing studies on prevention strategies
  • Genetic research for risk identification
  • Development of protective medications
  • Environmental factor research

When to See a Doctor

Early detection of leukemia can improve treatment outcomes. See a healthcare provider if you experience persistent symptoms that concern you.

Seek Immediate Medical Care For:

  • Severe, unexplained bleeding that won't stop
  • High fever with signs of infection
  • Extreme fatigue or weakness
  • Severe shortness of breath
  • Confusion or altered mental state
  • Severe headache with fever
  • Persistent vomiting

Schedule an Appointment For:

  • Unexplained, persistent fatigue
  • Frequent or unusual infections
  • Easy bruising or bleeding
  • Unexplained weight loss
  • Persistent fever or night sweats
  • Swollen lymph nodes that don't go away
  • Bone pain or tenderness
  • Fullness below the ribs

Risk-Based Screening

Regular check-ups recommended for:

  • Previous cancer treatment recipients
  • People with genetic syndromes
  • Those with significant chemical exposure
  • Family history of blood cancers

What to Tell Your Doctor

  • Complete list of symptoms and duration
  • Family history of cancer
  • Previous cancer treatments
  • Chemical or radiation exposure
  • All medications and supplements
  • Recent infections or illnesses

For Leukemia Patients

Contact your oncology team immediately for:

  • Fever over 100.4°F (38°C)
  • Signs of infection
  • Unusual bleeding
  • Severe side effects from treatment
  • New or worsening symptoms

Frequently Asked Questions

Is leukemia hereditary?

Most leukemias are not inherited. While having a family member with leukemia slightly increases risk, the vast majority of cases occur in people with no family history. Some genetic syndromes that run in families do increase leukemia risk, but these are rare.

Can leukemia be cured?

Many people with leukemia can be cured, especially children with ALL (cure rates over 90%). Acute leukemias often aim for cure, while chronic leukemias are typically managed as long-term conditions. Success depends on the type, genetic factors, age, and response to treatment.

What's the difference between leukemia and lymphoma?

Both are blood cancers, but leukemia primarily affects bone marrow and blood, while lymphoma starts in lymph nodes and lymphatic system. Leukemia cells circulate in the blood, while lymphoma typically forms tumors in lymph nodes. Some conditions can have features of both.

How long is leukemia treatment?

Treatment duration varies greatly by type. Acute leukemias require intensive treatment for 6-9 months, followed by maintenance therapy (2-3 years for ALL). Chronic leukemias may need ongoing treatment for years. Some targeted therapies for CML are taken indefinitely.

Can children get leukemia?

Yes, leukemia is the most common cancer in children, accounting for about 30% of all childhood cancers. ALL is the most common type in children. The good news is that childhood leukemia, especially ALL, has very high cure rates with current treatments.

What causes leukemia in children?

In most cases, the cause is unknown. Some factors include genetic conditions (like Down syndrome), previous cancer treatment, or exposure to high radiation. However, most children who develop leukemia have no known risk factors. It's not caused by anything parents did or didn't do.

Medical Disclaimer: This information is for educational purposes only and should not replace professional medical advice. Always consult with a qualified healthcare provider for diagnosis and treatment of leukemia or any medical condition. If you're experiencing symptoms that concern you, especially persistent fatigue, unusual bleeding, or frequent infections, seek medical evaluation promptly.

References

  1. American Cancer Society. Leukemia. ACS. 2024.
  2. National Cancer Institute. Leukemia—Patient Version. NCI. 2024.
  3. Leukemia & Lymphoma Society. Leukemia Facts and Statistics. LLS. 2024.
  4. Döhner H, et al. Acute Myeloid Leukemia. N Engl J Med. 2023.
  5. Malard F, Mohty M. Acute lymphoblastic leukaemia. Lancet. 2020.
  6. NCCN Clinical Practice Guidelines in Oncology. Acute Lymphoblastic Leukemia. Version 1.2024.