Overview
Acute lymphoblastic leukaemia is a type of cancer that affects white blood cells. It progresses quickly and aggressively and requires immediate treatment. Both adults and children can be affected.
Acute lymphoblastic leukaemia israre, with around 790 people diagnosed with the condition each year in the UK. Most cases of acute lymphoblastic leukaemia develop in children, teenagers and young adults.
Although it is rare, acute lymphoblastic leukaemia is the most common type of leukaemia that affects children. About 85% of the cases that affect children occur in those younger than 15 (mostly between the ages of 0 and 5). It affects slightly more boys than girls.
Acute lymphoblastic leukaemia is different to other types of leukaemia, including acute myeloid leukaemia, chronic lymphocytic leukaemia and chronic myeloid leukaemia.
What happens in acute lymphoblastic leukaemia
All of the blood cells in the body are produced by bone marrow, which is a spongy material found inside bones.
Bone marrow produces stem cells, which have the ability to develop into three important types of blood cells:
- red blood cells – which carry oxygen around the body
- white blood cells – which help fight infection
- platelets – which help stop bleeding
Bone marrow does not usually release stem cells into the blood until they have become fully developed blood cells. But in acute lymphoblastic leukaemia, large numbers of white blood cells are released before they are ready. These are known as blast cells.
As the number of blast cells increases, the number of red blood cells and platelet cells decreases. This causes the symptoms of anaemia, such as tiredness, breathlessness and an increased risk of excessive bleeding.
Also, blast cells are less effective than mature white blood cells at fighting bacteria and viruses, making you more vulnerable to infection.
Symptoms of acute lymphoblastic leukaemia
Acute lymphoblastic leukaemia usually starts slowly before rapidly becoming severe as the number of immature white blood cells (blast cells) in your blood increases.
Most of the symptoms are caused by the lack of healthy blood cells. Symptoms include:
- pale skin
- feeling tired and breathless
- repeated infections over a short time
- unusual and frequent bleeding, such as bleeding gums or nosebleeds
- high temperature
- night sweats
- bone and joint pain
- easily bruised skin
- swollen lymph nodes (glands)
- tummy (abdominal pain) – caused by a swollen liver or spleen
- unintentional weight loss
- a purple skin rash (purpura)
In some cases, the affected cells can spread from your bloodstream into your central nervous system. This can cause a series of neurological symptoms (related to the brain and nervous system), including:
- headaches
- seizures (fits)
- vomiting
- blurred vision
- dizziness
When to get medical advice
If you or your child has some or even all of the symptoms listed on this page, it's still highly unlikely that acute leukaemia is the cause. However, see a GP as soon as possible because any condition that causes these symptoms needs prompt investigation and treatment.
Find out more about diagnosing acute lymphoblastic leukaemia.
What causes acute lymphoblastic leukaemia?
A genetic change (mutation) in the stem cells that causes immature white blood cells to be released into the bloodstream.
What causes the DNA mutation to happen is not yet understood, but known risk factors include:
- previous chemotherapy – if you've had chemotherapy to treat another type of cancer in the past, your risk of developing acute lymphoblastic leukaemia is increased. The risk relates to certain types of chemotherapy medicine, such as etoposide, and how much treatment you had
- smoking – smokers are much more likely to develop acute leukaemia than non-smokers, and studies have shown that parents who smoke in the home may increase the risk of leukaemia in their children
- being very overweight (obese) – some studies have shown that people who are very overweight have a slightly higher risk of developing leukaemia than those who are a healthy weight
- genetic disorders – a small number of cases of childhood acute lymphoblastic leukaemia are thought to be related to genetic disorders, including Down's syndrome
- having a weakened immune system – people with lowered immunity (as a result of having HIV or AIDS or taking immunosuppressants) have an increased risk of developing leukaemia
Environmental factors
Extensive research has been done to determine whether the following environmental factors should be a trigger for leukaemia:
- living near a nuclear power station
- living near a power line
- living near a building or facility that releases electro-magnetic radiation, such as a mobile phone mast
There's currently no firm evidence to suggest that any of these environmental factors increases the risk of developing leukaemia.
Cancer Research UK has more information about acute lymphoblastic leukaemia risks and causes.
Treating acute lymphoblastic leukaemia
As acute lymphoblastic leukaemia is an aggressive condition that develops quickly, treatment usually begins a few days after diagnosis.
Treatment is usually done in the following stages:
- remission induction – the first stage of treatment aims to kill the leukaemia cells in your bone marrow, restore the balance of cells in your blood and resolve any symptoms you may have
- consolidation – this stage aims to kill any remaining leukaemia
- maintenance – this stage involves taking regular doses of chemotherapy medicines to prevent the leukaemia from returning
Chemotherapy is the main treatment for acute lymphoblastic leukaemia. Other treatments you may need include antibiotics and blood transfusions. Sometimes a stem cell transplant may also be needed to achieve a cure.
Read more about treating acute lymphoblastic leukaemia.
Complications of acute lymphoblastic leukaemia
If a cure for acute lymphoblastic leukaemia is not possible, there's a risk that the lack of healthy blood cells can make the person:
- extremely vulnerable to life-threatening infections (because they do not have enough healthy white blood cells to fight infections)
- prone to uncontrolled and serious bleeding (because there are not enough platelets in their blood)
These two complications, and others, are discussed further in complications of acute lymphoblastic leukaemia.
Outlook
One of the biggest factors that affects the outlook for people with acute lymphoblastic leukaemia is age. The younger a person is when they are diagnosed and treatment begins, the better the outlook.
Help and support
If you or a family member has been diagnosed with acute lymphoblastic cancer, Leukaemia Care provides further information, advice and support.
Call Leukaemia Care's free helpline on 08088 010 444 or email: support@leukaemiacare.org.uk
The charity Cancer UK also has more information about acute lymphoblastic leukaemia.
Treatment
Acute lymphoblastic leukaemia develops quickly, so treatment usually begins a few days after diagnosis.
Stages of treatment
Treatment for acute lymphoblastic leukaemia is usually done in 3 stages.
Stage 1 is remission induction. The aim of remission induction is to kill the leukaemia cells in your bone marrow, restore the balance of cells in your blood and relieve your symptoms.
Stage 2 is consolidation. This aims to kill any remaining leukaemia cells.
Stage 3 is maintenance. This involves taking regular doses of chemotherapy medicines to stop leukaemia coming back.
Remission induction
The remission induction stage of treatment is done in hospital or at a specialist centre.
You'll probably need regular blood transfusions because your blood will not contain enough healthy blood cells.
You'll also be vulnerable to infection, so it's important you're in a sterile environment where your health can be carefully monitored and any infections can be treated quickly.
Antibiotics may also be given to help prevent infection.
Chemotherapy
You'll have chemotherapy to kill the leukaemia cells in your bone marrow. The chemotherapy medicine used is called methotrexate.
Although some medicine comes as a tablet, you'll also need it to be given as an injection.
To make injections easier, you may have a flexible tube (a central line) put into a vein in your chest, which is used to give you medicines.
You may also have chemotherapy medicine injected into the fluid that surrounds and protects the spine (cerebrospinal fluid) to kill any leukaemia cells that may have spread to your nervous system and brain. This is given in a similar way to a lumbar puncture.
After an injection into your spine you'll have to lie flat for a few hours with your head slightly lower than your feet. You may have a headache or feel sick afterwards.
Methotrexate is also given into a vein (intravenously) in adults with acute lymphoblastic leukaemia after remission induction therapy and before consolidation.
Common side effects of chemotherapy include:
The side effects should get better once treatment has finished.
Find out more about what happens during chemotherapy
Steroid therapy
You may also be given steroid (corticosteroid) injections or tablets to help improve the effectiveness of chemotherapy.
Targeted therapies
If you have a type of leukaemia called Philadelphia chromosome-positive acute lymphoblastic leukaemia (which affects around 20 to 30% of people with acute lymphoblastic leukaemia), you'll also be given a medicine called imatinib.
Imatinib is a targeted therapy, which works blocks signals in the cancerous cells that cause them to grow and reproduce. This kills the cancerous cells.
Imatinib comes as a tablet. The side effects are usually mild and should improve over time.
They include:
- feeling or being sick
- swelling in the face and lower legs
- muscle cramps
- skin rash
- diarrhoea
Depending on how well you respond to treatment, the remission induction phase can last from 2 weeks to several months.
Sometimes you may be able to leave hospital and receive treatment on an outpatient basis if your symptoms improve.
If other treatments do not work, your cancer comes back or you have a certain type of acute lymphoblastic leukaemia, you may be given a different targeted therapy. The 2 alternative medicines used are:
These come as a tablet and cause similar side effects to imatinib.
Want to know more about targeted therapies?
Consolidation
The aim of consolidation treatment is to ensure that any remaining leukaemia cells are killed.
The consolidation phase involves regular injections of chemotherapy medicine.
This is usually done on an outpatient basis, so you will not have to stay in hospital overnight.
But you may need some short stays in hospital if your symptoms suddenly get worse or you get an infection.
The consolidation phase lasts several months.
Maintenance
The maintenance phase is a further step to help ensure the leukaemia does not come back.
It involves taking regular doses of chemotherapy medicine while having regular check-ups to monitor your treatment.
The maintenance phase can often last for 2 years.
Other treatments
As well as chemotherapy, steroids and targeted therapies, other treatments are sometimes used.
Radiotherapy
Radiotherapy is where high doses of controlled radiation are used to kill cancerous cells.
It's usually used to treat acute lymphoblastic leukaemia when:
- acute lymphoblastic leukaemia has spread to the nervous system or brain
- the body needs to be prepared for a bone marrow transplant
Side effects of radiotherapy include:
- hair loss
- feeling sick
- fatigue
These side effects should pass after your course of radiotherapy has been finished.
Your skin may be very sensitive to the effects of light for several months after treatment has finished. If this happens, avoid sunbathing or exposure to artificial sunlight, such as sunbeds, for several months.
Many young children treated with radiotherapy will go on to have restricted physical growth during puberty.
A small number of people develop cataracts several years after having radiotherapy.
Cataracts are cloudy patches in the transparent structure at the front of the eye (the lens) that can make your vision blurred or misty.
They can usually be successfully treated using cataract surgery.
Stem cell and bone marrow transplants
A stem cell and bone marrow transplant is an alternative treatment option if you do not respond to chemotherapy.
A transplant of bone marrow and stem cells is usually more successful if the donor has the same tissue type as you, so the ideal donor is usually a brother or sister.
Before a transplant can happen, the person receiving the transplant will need to have high-dose chemotherapy and radiotherapy to destroy any cancerous cells in their body.
This can put a big strain on the body, so transplants are usually only successful when they're done in:
- children and young people
- older people who are in good health
- when there's a suitable donor, such as a brother or sister
Recent research has shown it's possible for people over the age of 40 to have a reduced-intensity stem cell transplant.
This is where lower than normal doses of chemotherapy and radiotherapy are used before the transplant, which places less strain on the body.
Immunotherapy
Immunotherapy is a type of treatment where medicines are used to encourage the body's immune system to target and kill cancerous cells.
Immunotherapy may be recommended if you do not respond to other treatments or the cancer comes back after other treatments.
There are 2 immunotherapy medicines used to treat acute lymphoblastic leukaemia:
- blinatumomab
- inotuzumab ozogamicin
Tese medicines are given through a drip into a vein.
Side effects of immunotherapy include:
- flu-like symptoms, such as high temperature, chills and muscle aches
- dizziness
- headaches
- bleeding
- feeling and being sick
Immunotherapy can also make you more vulnerable to infection. Talk to your care team for advice if you suddenly feel very unwell.
Clinical trials
In the UK, clinical trials are currently being done to find the best way of treating types of acute leukaemia.
These studies are using innovative new techniques to see how well they work in treating and possibly curing acute leukaemia.
It's important to be aware of new studies so you can choose which treatments to have.
But there's no guarantee the techniques being studied in the clinical trial will be more effective than current treatments.
Your care team will be able to tell you whether there are any clinical trials available in your area and can explain the benefits and risks involved.