Overview
Leukaemia is cancer of the blood and bone marrow, characterised by uncontrolled production of abnormal white blood cells that crowd out normal blood cells. The four main types are acute lymphoblastic (ALL), acute myeloid (AML), chronic lymphocytic (CLL), and chronic myeloid (CML). Treatment and prognosis vary markedly by type and age.
How common is it?
Leukaemia accounts for about 3% of all cancers in the UK, with approximately 10,000 new cases annually. ALL is the most common childhood cancer. CLL is the most common leukaemia in adults, predominantly affecting people over 60.
Causes and risk factors
Leukaemia results from acquired or inherited genetic mutations that cause abnormal proliferation and arrested maturation of haematopoietic cells.
Common risk factors
- Previous radiation or chemotherapy exposure
- Benzene exposure
- Genetic syndromes: Down syndrome (40-fold increased ALL risk), Fanconi anaemia, ataxia-telangiectasia
- Chromosomal abnormalities: Philadelphia chromosome t(9;22) in CML and ALL
- Viral infections: HTLV-1 (T-cell leukaemia), EBV
- Smoking (increases AML risk)
- Inherited predisposition (rare familial leukaemia syndromes)
- Age: CLL almost exclusively in older adults
Symptoms
- Fatigue and breathlessness (anaemia from bone marrow failure)
- Increased bleeding and bruising (thrombocytopenia)
- Recurrent or severe infections (neutropenia)
- Fever, night sweats
- Unexplained weight loss
- Bone and joint pain (particularly in ALL in children)
- Swollen lymph nodes and spleen (CLL/CML)
- Pale skin
When to see a doctor
Seek urgent GP assessment for unexplained bruising, persistent infections, fever without obvious cause, or significant fatigue. These require a full blood count urgently.
Diagnosis
Full blood count and blood film: abnormal white cells and reduced normal cell lines. Bone marrow aspirate and trephine biopsy confirms diagnosis and type. Cytogenetics and molecular testing (e.g. BCR-ABL for CML) guides treatment. Immunophenotyping by flow cytometry.
Treatments
Chemotherapy
Combination chemotherapy is the backbone of ALL and AML treatment, given in phases: induction, consolidation, and maintenance. Modern ALL regimens achieve remission in over 90% of children.
Targeted therapy
Tyrosine kinase inhibitors (imatinib, dasatinib) for CML with BCR-ABL mutation produce 90% 10-year survival with daily oral tablets. This transformed CML from a fatal disease to a manageable chronic condition.
Allogeneic stem cell transplant
Potentially curative for AML and ALL by replacing the bone marrow with donor cells that provide both new haematopoiesis and graft-versus-leukaemia effect. Reserved for high-risk disease.
Watchful waiting (CLL)
Many patients with early-stage CLL do not require immediate treatment. Treatment (BTK inhibitors such as ibrutinib, or chemoimmunotherapy) is started when disease progresses.
Self-care and lifestyle
- Avoid infection vigilantly during intensive chemotherapy (high infection risk)
- Ensure vaccinations are up to date before starting immunosuppressive treatment
- Bone marrow or stem cell donation is desperately needed from diverse ethnic backgrounds
- Maintain nutrition during treatment to support recovery
Prevention
Most leukaemia is not preventable. Avoiding smoking reduces AML risk. Occupational benzene exposure is regulated. Early genetic counselling for known familial risk.