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
- DNA Mutations: Changes occur in the genetic material of blood cells
- Abnormal Cell Growth: Mutated cells multiply uncontrollably
- Crowding Effect: Abnormal cells crowd out healthy cells
- 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
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.
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.
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.
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.
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.
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.
References
- American Cancer Society. Leukemia. ACS. 2024.
- National Cancer Institute. Leukemia—Patient Version. NCI. 2024.
- Leukemia & Lymphoma Society. Leukemia Facts and Statistics. LLS. 2024.
- Döhner H, et al. Acute Myeloid Leukemia. N Engl J Med. 2023.
- Malard F, Mohty M. Acute lymphoblastic leukaemia. Lancet. 2020.
- NCCN Clinical Practice Guidelines in Oncology. Acute Lymphoblastic Leukemia. Version 1.2024.