The bone marrow and blood cells
All of the blood cells in your body are produced in the bone marrow: the spongy tissue that is found in the middle of your bones. All blood cells start their lives as stem cells. These grow and divide within the bone marrow and mature into:
- Red blood cells that carry oxygen around the body
- White blood cells that help fight infection
- Platelets that help clot the blood to control bleeding and bruising.
When leukaemia occurs, the bone marrow produces a large amount of immature blood cells, which do not develop any further. These do not work properly as they have not matured into the type of cell they were supposed to be.
Leukaemia usually affects the production of white blood cells, of which there are a several types. Acute Lymphoblastic Leukaemia (ALL) is named after the early lymphoid cells (‘lymphoblasts’) that it affects. Acute myeloid leukaemia (AML) is named after the early myeloid blood cells it affects. See our acute myeloid leukaemia page for more information about the diagnosis and treatment of this cancer.
Acute lymphoblastic leukaemia can affect young people of any age, but it is most common in children aged one to four. It is slightly more common in males than females.
When leukaemia occurs, the over production of immature white blood cells squeezes out the production of healthy blood cells. This can lead to:
- Anaemia: the number of red blood cells are reduced, leaving you feeling tired, breathless and constantly run down
- Bruising and bleeding: the number of platelets are reduced, which means your blood is not able to clot as well as it did previously
- Infections: you may get infections more often as there are less healthy blood cells to fight them.
Acute lymphoblastic leukaemia is usually suspected from a blood test, which may show changes in the numbers of healthy white blood cells, red cells and platelets. If the blood test suggests that leukaemia is present, a specialist will need to take a sample of your bone marrow. This sample will be looked at under a microscope to work out what type of leukaemia you have.
Your specialist will also need to do a lumbar puncture to see if your spinal fluid contains any leukaemia cells.
Acute lymphoblastic leukaemia is treated with chemotherapy, which involves a combination of drugs being delivered into your bloodstream to kill the leukaemia cells and allow the bone marrow to work normally.
There are four different phases of ALL treatment.
- The first phase aims to destroy your leukaemia cells with chemotherapy and get you into remission. When you are in remission, there are no leukaemia cells visible through a microscope in your blood or bone marrow.
- You will then have consolidation therapy to stop your leukaemia coming back. This most often involves more chemotherapy.
- The next stage is interim maintenance therapy to help keep the leukaemia in remission, followed by a ‘delayed intensification’ block where you will receive a number of different anti-cancer drugs over several weeks.
- In the final maintenance phase, you will receive low-dose chemotherapy. Girls will receive two years treatment after the start of interim maintenance and boys three years after the start of interim maintenance. This treatment is done in an out-patient setting and is much less disruptive to your normal life than earlier parts of the treatment.
A few young people require a bone marrow or stem cell transplant early in their treatment, once they are in remission. Others may require a transplant if the leukaemia comes back once they have finished the treatment.
Your particular treatment plan will depend on your leukaemia and how it responds to treatment, so it’s best to talk to your specialist about what will be involved.
If you are undergoing chemotherapy, you may experience side-effects such as tiredness, sickness, diarrhoea and temporary hair loss. You will also be at greater risk of infections. For more information about how side-effects can be managed, talk to your specialist or nurses, or see the side-effects section of our website.
After your treatment is complete you will still need to be seen regularly at an outpatient clinic. At this clinic, your specialist will be looking for any signs that your cancer has returned (this is known as a relapse). They will also check that your major organs, such as your heart and lungs, are still functioning correctly and haven’t been affected by your cancer treatment.
Long-term follow up
Once your risk of relapse has reduced, the focus of on-going follow up changes to looking out for potential long term side effects of treatment. The risk of long term side effects depends on the type of cancer you had and the treatment you received. A personalised surveillance plan is usually created that outlines the specific long term follow up and on-going investigations that you require. Many people are at low risk of future health problems but some will have significant on-going health needs.
The standard treatment for ALL, received by most children and young people, carries a low risk for long-term health problems. However, if you need more intensive treatment or a transplant, you may later experience fatigue, a lower resistance to infections, infertility, heart or thyroid problems, or other health issues. Talk to your specialist about the potential long-term side-effects of your treatment.
Updated December 2014, next review planned 2017.