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Acute lymphoblastic leukaemia, risk-adapted chemotherapy, TKIs and CAR-T.

The most common childhood cancer, and a treatable adult malignancy. A guide to subtypes, diagnosis, chemotherapy phases and modern immunotherapy.

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A radiographer guides a patient onto the bed of an advanced 3 Tesla MRI scanner in a London imaging suite

Why trust this guide

  • 01

    Editorial team

    Written by our editorial team from the UK sources listed on each page.

  • 02

    Sourced from guidance

    Checked against NICE, BSH, ESMO and NCCN guidance, plus recent MHRA and EMA licensing.

  • 03

    Current for 2026

    Reflects modern UK practice including risk-adapted chemotherapy, tyrosine kinase inhibitors and CAR-T therapy.

Key facts

ALL at a glance.

The essentials, in plain English: what ALL is, who it affects, the main subtypes and how it is treated in the UK today.

  • What it is

    A malignancy of lymphoid precursor cells (lymphoblasts) that crowd out the bone marrow and spill into the blood, lymph nodes and organs.

  • Who it affects

    Peak incidence in childhood (2 to 10 years) but occurs across the lifespan. Paediatric cure rates reach 85 to 90 per cent; adult outcomes are lower at 30 to 40 per cent.

  • Main subtypes

    B-cell precursor ALL (most common), T-cell ALL and mature B-cell (Burkitt-like) ALL, each with distinct biology and treatment.

  • Ph-positive ALL

    A subset carries the BCR-ABL1 fusion (Philadelphia chromosome) and is treated with a tyrosine kinase inhibitor alongside chemotherapy.

  • Backbone of therapy

    Induction, CNS prophylaxis, consolidation and 2 to 3 years of maintenance, with allogeneic stem-cell transplant reserved for high-risk disease.

  • Modern immunotherapy

    CAR-T cell therapy (tisagenlecleucel), blinatumomab and inotuzumab ozogamicin have transformed outcomes in relapsed and refractory disease.

Why this guide matters

A curable cancer, with the right plan.

ALL was once uniformly fatal. Modern risk-adapted therapy, TKIs and immunotherapy have transformed outcomes. Three principles shape everything on this page.

  • Subtype defines treatment

    B-cell, T-cell and Ph+ disease all respond to different regimens. Immunophenotyping and molecular testing at diagnosis are non-negotiable.

  • Long treatment, real results

    A 2 to 3 year plan sounds daunting, but paediatric cure rates of 85 to 90 per cent are among the best in oncology.

  • Immunotherapy has changed relapse

    CAR-T, blinatumomab and inotuzumab now offer durable remissions after chemotherapy has failed - and are moving earlier in the treatment path.

How the diagnosis is made

From first blood test to a full risk profile.

The pathway a UK haemato-oncology team follows, in order, so you know what each step means and why it matters.

  1. 01

    Suspecting

    Full blood count and smear

    Anaemia, thrombocytopenia and abnormal white cells with circulating blasts on the peripheral blood film usually raise the first suspicion.

  2. 02

    Suspecting

    Clinical assessment

    A careful history and examination looking for pallor, bruising, infection, lymphadenopathy, hepatosplenomegaly, bone pain and, in men, testicular enlargement.

  3. 03

    Suspecting

    Urgent haematology referral

    Any suspected acute leukaemia is a same-day referral to a specialist haemato-oncology centre.

  4. 04

    Confirming

    Bone marrow aspirate and biopsy

    Confirms the diagnosis when 20 per cent or more of marrow cells are lymphoblasts and provides material for full characterisation.

  5. 05

    Confirming

    Immunophenotyping

    Flow cytometry separates B-lineage from T-lineage disease and identifies the maturation stage of the leukaemic clone.

  6. 06

    Confirming

    Cytogenetics, FISH and molecular

    Looks for BCR-ABL1, KMT2A (MLL) rearrangements, ETV6-RUNX1, TCF3-PBX1, hyperdiploidy and hypodiploidy to assign risk and guide therapy.

  7. 07

    Staging

    Lumbar puncture and imaging

    CSF examination stages central nervous system involvement; a chest CT or MRI checks for a mediastinal mass, particularly in T-cell ALL.

Typical timeline: from first blood count to a fully characterised diagnosis and induction plan within days.

Symptoms

What ALL can look like.

The features that come from bone marrow failure and organ infiltration, and the combinations that mean same-day review.

  • Fatigue and pallor

    From marrow failure and anaemia; often the first symptom parents or partners notice.

  • Bruising and bleeding

    Easy bruising, petechiae, nosebleeds and gum bleeding driven by low platelets.

  • Fevers and infection

    Neutropenia predisposes to recurrent or severe infection, sometimes the presenting feature.

  • Swollen lymph nodes

    Painless nodes in the neck, armpits or groin, and sometimes an enlarged liver or spleen.

  • Bone and joint pain

    A deep, unrelenting ache in the long bones or back from marrow expansion, common in children.

  • Mediastinal mass (T-ALL)

    A large thymic mass may cause cough, breathlessness or superior vena cava obstruction in T-cell disease.

  • CNS and testicular disease

    Headache, cranial nerve signs or a firm painless testicular swelling suggest sanctuary-site involvement.

  • Red flag - unwell child or adult

    Any combination of bruising, fever and profound fatigue needs urgent bloods and same-day haematology review.

Treatment

How ALL is treated in the UK.

A four-phase chemotherapy backbone, tyrosine kinase inhibitors for Ph+ disease and modern immunotherapy for high-risk or relapsed cases.

  • Induction chemotherapy

    A 4 to 6 week combination of dexamethasone, vincristine, asparaginase and an anthracycline aimed at achieving morphological remission.

  • CNS prophylaxis

    Intrathecal methotrexate (sometimes with cytarabine and hydrocortisone) prevents relapse in the brain and spinal cord.

  • Consolidation therapy

    Intensified multi-agent blocks, often including high-dose methotrexate and cytarabine, to deepen the response.

  • Maintenance therapy

    Daily mercaptopurine and weekly methotrexate for 2 to 3 years, with periodic vincristine and steroid pulses to prevent relapse.

  • Allogeneic stem-cell transplant

    Considered in first remission for high-risk disease and most adults with poor-risk features, using a matched sibling or unrelated donor.

  • Tyrosine kinase inhibitor (Ph+ ALL)

    Imatinib or dasatinib is added to chemotherapy in Philadelphia-positive disease and continues into maintenance.

  • Immunotherapy (blinatumomab, inotuzumab)

    A CD19/CD3 bispecific antibody and a CD22 antibody-drug conjugate used for measurable residual disease and relapsed or refractory B-cell ALL.

  • CAR-T cell therapy

    Tisagenlecleucel (Kymriah), a CD19-directed CAR-T therapy licensed by the FDA and EMA, for paediatric and young adult relapsed or refractory B-cell ALL.

What this guide is based on

The sources behind every claim on this page.

UK national guidance, international haemato-oncology society standards and current EMA and MHRA product information.

Key references

Guidelines and standards we relied on.

A quiet reminder

This guide is for information, not medical advice.

Your haemato-oncology team knows your subtype, risk group and history and can tell you which parts of this guide apply to you.

  • NICE. Haematological cancers: improving outcomes (NG47) and related technology appraisals.

  • British Society for Haematology (BSH). Guidelines on the diagnosis and management of adult and paediatric ALL.

  • ESMO Clinical Practice Guidelines. Acute lymphoblastic leukaemia in adult patients.

  • NCCN Clinical Practice Guidelines in Oncology. Acute Lymphoblastic Leukemia.

  • EMA and MHRA. Product information for tisagenlecleucel (Kymriah), blinatumomab and inotuzumab ozogamicin.

Red flags

When ALL becomes an emergency.

Situations during and after treatment that need immediate contact with your haematology team or emergency care.

  • Neutropenic fever

    Temperature 38 degrees or above during treatment is a medical emergency needing intravenous antibiotics within an hour.

  • Tumour lysis syndrome

    Rapid cell breakdown at diagnosis or during induction can cause acute kidney injury, arrhythmias and needs urgent hydration and rasburicase.

  • CNS symptoms

    New headache, vomiting, cranial nerve palsies or seizures need urgent imaging and lumbar puncture to look for CNS relapse.

  • Mediastinal mass with airway compromise

    Breathlessness, facial swelling or stridor in T-cell ALL is a superior vena cava emergency requiring immediate oncology input.

  • Severe bleeding

    Spontaneous bleeding, especially intracranial or gastrointestinal, needs urgent platelet transfusion and coagulation support.

  • Sepsis on chemotherapy

    Hypotension, confusion or new organ dysfunction in a patient on chemotherapy is life-threatening and needs critical care assessment.

  • Cytokine release syndrome after CAR-T

    Fever, hypotension and hypoxia in the days after CAR-T infusion is managed with tocilizumab and supportive care.

  • ICANS (neurotoxicity after CAR-T)

    Confusion, tremor, dysphasia or seizures after CAR-T need urgent neurological review and steroid therapy.

  • Relapse suspicion

    Reappearance of blasts, unexplained cytopenias or new bone pain during maintenance warrants an urgent marrow re-evaluation.

Living with it

A long treatment, and a full life beyond it.

Four things that make the biggest difference during and after ALL treatment: rhythm, vigilance, gradual return and long-term follow-up.

A quiet reminder

One day at a time, one cycle at a time.

The treatment map is long, but each block has an end. Your team will help you and your family plan around it.

  1. 01 Rhythm

    Long treatment, small steps

    ALL treatment lasts years, not weeks. Small daily routines around medicines and bloods make the journey manageable.

  2. 02 Infection

    Vigilance without fear

    Know the temperature threshold, keep the emergency card to hand and call the 24-hour line early rather than late.

  3. 03 School and work

    Return on your terms

    Children can often return to school in maintenance; adults may work in adjusted roles. Your team will help plan a graded return.

  4. 04 Follow-up

    Life after treatment

    Long-term follow-up watches for late effects on heart, endocrine, fertility and second cancers, and supports emotional recovery.

Frequently asked

Everything we get asked about ALL.

Quick answers on diagnosis, subtypes, chemotherapy phases, CAR-T and prognosis.

  • What is acute lymphoblastic leukaemia (ALL)?

    ALL is an aggressive cancer of the lymphoid precursor cells in the bone marrow. Immature lymphoblasts multiply rapidly, crowd out normal blood cells and can infiltrate the lymph nodes, liver, spleen, central nervous system and testes. It is the most common childhood cancer in the UK but also affects adults.

  • How is ALL diagnosed?

    Diagnosis starts with a full blood count and blood film showing abnormal lymphoblasts, followed by a bone marrow aspirate and biopsy. Immunophenotyping by flow cytometry defines B-cell or T-cell lineage, and cytogenetic, FISH and molecular tests look for BCR-ABL1, KMT2A rearrangements, ETV6-RUNX1, TCF3-PBX1 and ploidy changes. A lumbar puncture stages central nervous system involvement.

  • What is Philadelphia-positive (Ph+) ALL?

    About one in four adults and a smaller proportion of children have a BCR-ABL1 fusion gene arising from the Philadelphia chromosome translocation. This subtype is treated with a tyrosine kinase inhibitor such as imatinib or dasatinib alongside chemotherapy, which has substantially improved outcomes.

  • What does treatment involve?

    Treatment has four phases: induction (dexamethasone, vincristine, asparaginase and an anthracycline) to achieve remission; CNS prophylaxis with intrathecal methotrexate; consolidation with intensified multi-agent chemotherapy; and 2 to 3 years of maintenance with mercaptopurine and methotrexate. Allogeneic stem-cell transplant is reserved for high-risk disease.

  • What is CAR-T therapy for ALL?

    CAR-T (chimeric antigen receptor T-cell) therapy uses genetically engineered T-cells that target CD19 on B-cell leukaemia cells. Tisagenlecleucel (Kymriah) is licensed by the FDA and EMA for paediatric and young adult patients with relapsed or refractory B-cell ALL and can deliver durable remissions after other treatments have failed.

  • What is the outlook for ALL?

    Outcomes have improved dramatically. In UK children, five-year overall survival is 85 to 90 per cent with modern risk-adapted protocols. Adult outcomes are lower at 30 to 40 per cent overall but improving with immunotherapy, CAR-T and better donor transplants. Relapsed disease still carries significant risk and needs early access to novel therapies.

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