Blood cells are formed in the bone marrow, which is the spongy tissue found inside the bones. Blood-forming stem cells divide to produce either more stem cells or immature cells that become mature blood cells over time. In ALL, the process is out of control and the cells continues to divide but not mature.
A lymphoid stem cell becomes a lymphoblast cell and then one of three types of lymphocytes (white blood cells):
- B lymphocytes that make antibodies to help fight infection.
- T lymphocytes that help B lymphocytes make the antibodies that help fight infection.
- Natural killer cells that attack cancer cells and viruses.
Acute lymphoblastic leukaemia (ALL) most commonly affects B lymphocytes. The overproduction of immature B lymphocytes means the body cannot fight infection.
Acute leukaemia progresses rapidly, but it can often be cured with standard treatments, especially in younger or fitter patients.
What causes Acute Lymphoblastic Leukaemia?
In most cases of ALL there is no obvious cause and it is important to understand that:
- It is not a condition which can be caught from someone else (contagious)
- It is not passed on from a parent to a child (inherited)
- Age – Most forms of leukaemia are more common in older people. ALL is an exception to this and the peak incidence is in children, aged between about two to five years. In adults it follows the same pattern as other leukaemias, becoming more common with age
- Being male – ALL affects males more than females at all ages
- Infection – It is thought that one of the factors in development of childhood ALL is an abnormal immune response to a common infection
- Other factors – There is no persuasive evidence that proximity to powerlines, living near nuclear power stations, mobile phones or any other environmental exposures play a significant part in causing ALL
Signs and Symptoms
There are no specific signs or symptoms which would allow a diagnosis of ALL to be made. The most common signs and symptoms are caused by the bone marrow being unable to produce enough normal blood cells.
- Anaemia – due to lack of red blood cells
- Weakness, tiredness, shortness of breath, light-headedness, palpitations
- Infections – due to lack of normal white blood cells
- Infections are more frequent, more severe and last longer
- Fever, malaise (general feeling of illness) and sweats
- Purpura (small bruises in skin), nosebleeds, bleeding gums
- Bleeding and bruising – due to lack of platelets
Other common signs and symptoms include:
- About half of all patients have enlarged lymph nodes (glands)
- About half of all patients have enlarged spleen or liver
- Children often complain of joint or leg pains. A very young child may be reluctant to walk/crawl
Although a doctor may suspect a patient has ALL based on signs and symptoms, it can only be diagnosed by laboratory tests. The results of a simple blood count will usually indicate ALL although, rarely, a blood count may be normal. Virtually all patients with ALL will have bone marrow samples taken to confirm the diagnosis and to help to determine exactly what type of leukaemia a patient has. More specialised tests are often done at the same time.
Usually, a chest x-ray will be taken and also scans, to look for swollen lymph nodes, or other affected sites. Blood samples will be taken to test for any problems with the liver, kidneys or other organs. In ALL a sample is taken of the fluid which surrounds the brain and spinal cord – cerebrospinal fluid (CSF). This is because ALL cells can get into the nervous system, which protects them from most kinds of treatment. Some blood tests and scans will be repeated to check for the response to treatment and any complications. Other tests are usually only done at diagnosis.
Other tests which may be done include:
- Lumbar puncture – a sample of fluid (CSF) from around the spine to show whether there are leukaemia cells in the nervous system
- X-rays, ultrasound or scans (CT or MRI) – To monitor impact on organs of the body
Blood tests, bone marrow samples and lumbar punctures will be repeated throughout treatment to monitor response.
Staging is not used for ALL, because it is spread throughout the body when first diagnosed. There is a system to classify ALL as high-risk, standard or low-risk. It is important to stress that this refers to the chance of a good response following standard treatment. If treatment is selected according to risk group, many patients with high-risk disease will do very well. It is also, unfortunately, not always true that a patient with low risk disease will do well. The risk group is only of the factors which affects the outcome of treatment.
If you are being treated for any type of leukaemia, you may be asked to consider taking part in a clinical trial. Clinical trials are scientific studies to find the best treatment; you can find out more here.
Virtually all patients with ALL will start treatment immediately. The main exception would be if a patient is very ill with other medical problems and is not fit enough to receive treatment. Acute leukaemia is very often curable with standard treatments, in younger and/or fitter patients. Older or less fit patients will usually have a good initial response to treatment but the condition will most often come back, this is known as a relapse.
The main ways in which ALL is treated are:
- Chemotherapy – Cell-killing drugs. Steroids are normally used along with chemotherapy for ALL
- Radiation therapy – Usually only given as part of a stem cell transplant in ALL
- Stem cell transplant – Younger/fitter patients may be given a stem cell transplant (bone marrow transplant). This is done using healthy stem cells from a donor. This is done for ALL if chemotherapy does not cure the disease
- Targeted therapy – Drugs which specifically recognise and kill leukaemia cells
Chemotherapy is the use of cell-killing drugs. These kill the cancer cells and/or stop them from dividing. Chemotherapy is usually given in blocks or ‘cycles’ of treatment. One cycle of treatment will consist of a series of doses of chemotherapy followed by a break for the healthy cells to recover. After initial treatment is complete lower-dose chemotherapy is continued for 2-3 years. This is called maintenance therapy.
ALL cells may be found in the fluid around the brain and spine (called CSF) so chemotherapy for ALL includes injections into this fluid. This is called intrathecal chemotherapy.
Chemotherapy is normally given as a combination of drugs, which, for ALL, will almost always include steroids. Steroids used to treat lymphoid leukaemia are a laboratory-made version of chemicals naturally made by the body. They are very different from the type of steroids sometimes misused by body builders or sportsmen.
The details of treatment will vary depending on the specific features of the leukaemia, age and general fitness. Patients will be given a chance to discuss treatment options and detailed information on their treatment plan before it starts. The side effects of treatment vary between different types of treatment and different patients.
Targeted therapy is used in one particular form of ALL, in which there is an abnormality called the Philadelphia chromosome. This form may respond well to a type of drug called a tyrosine kinase inhibitor (TKI).
Patients will be given detailed information about any likely side effects before treatment starts.
Questions to ask your doctor
We understand going through a blood cancer through journey can be difficult. It may help to talk to a close friend or relative about how you are feeling. Here are some questions that may be useful to ask your doctor.
- How would I know if I had ALL?
- What tests will I need to have?
- What will the tests show?
- How long will the results take?
- How rare is ALL?
- What sort of treatment will I need?
- How long will my treatment last?
- What will the side effects be?
- Is there anything I should or shouldn’t eat?
- Will I be able to go back to work?
- Where can I get help with claiming benefits and grants?
- Where can I get help dealing with my feelings?
We have free patient information available for ALL patients.
You can download the booklets on our information pages here.
Alternatively, you can have the information delivered free of charge by requesting it through our resources page.
Support for ALL patients
There is also a general leukaemia support group on Facebook which is ran by Leukaemia Care. To request to join, click here.
Offline support groups
There area number of haematology support groups in the UK. Find out more on our support groups page.
Acute Leukemia Advocates Network (ALAN)
ALAN is an independent global network of patient organisations, dedicated to changing outcomes of patients with acute leukemias. It aims to build capacity in the members of the network to deliver tailored services to acute leukemia patients and carers on the national level, while joining forces between organisations on the policy and research level across countries.
Other ALL charities
BPositive aim is to provide support, information and access as well as promoting the cause and case of patients with acute leukaemia and their families. Find out more on their website at bpositive.org.uk
Published date: August 2016
Review date: August 2018