Chronic lymphocytic leukaemia (CLL)
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What is chronic lymphocytic leukaemia (CLL)?
Symptoms of chronic lymphocytic leukaemia (CLL)
Causes and risk factors of chronic lymphocytic leukaemia (CLL)
Diagnosing chronic lymphocytic leukaemia (CLL)
Stages of chronic lymphocytic leukaemia (CLL)
Treatment for chronic lymphocytic leukaemia (CLL)
Living with chronic lymphocytic leukaemia (CLL)
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How we can help
Chronic lymphocytic leukaemia (also called CLL or CLL leukemia) is the most common type of leukaemia. About 3,800 people in the UK are diagnosed with CLL each year. It is more common in older people.
We have separate information on other types of leukaemia.
How does CLL develop?
Blood cells are made in the bone marrow. The bone marrow is a spongy material in the middle of our bones. All blood cells are made from blood stem cells. These are blood cells at the earliest stage of their development. The new, developing blood cells are called blast cells.
There are 2 types of blood stem cell:
- lymphoid stem cells make a type of white blood cell called lymphocytes.
- myeloid stem cells make all the other types of blood cell. These include red blood cells, platelets, and other types of white blood cells, such as neutrophils.
CLL is a cancer of the white blood cells, which develop from B lymphocytes. In people with CLL, the bone marrow makes too many abnormal white blood cells, called lymphocytes. These cells look normal under a microscope. But they are not fully developed (immature) and do not work properly.
Over time, these abnormal lymphocytes build up in the lymphatic system and may cause large, swollen lymph nodes. The abnormal lymphocytes can also build up in the bone marrow. This leaves less space for normal white blood cells, red blood cells and platelets to develop.
CLL usually develops very slowly, which is why it is called a chronic leukaemia. Many people with CLL do not need treatment for months or years. If you have symptoms, you may need treatment sooner.
What are lymphocytes?
Lymphocytes are a type of white blood cell. They move around the body in the blood and the lymphatic system. Lymphocytes are an important part of the body’s defence. They fight against germs such as bacteria, fungal infections and viruses. They do this by:
- killing germs directly
- making special proteins called antibodies that stick to germs and make it easier for other white blood cells to find and kill them
- remembering and recognising germs – lymphocytes can live for a very long time, so they can quickly fight any infection you have had before
Small lymphocytic leukaemia
In many people with CLL, the leukaemia cells are mainly in the bloodstream and the bone marrow. If the leukaemia cells are mainly in the lymph nodes, the disease is called small lymphocytic lymphoma (SLL). CLL and SLL are now considered to be the same disease and are treated in the same way.
We do not know what causes CLL, but research is going on to find out more about it. Certain things called risk factors can increase the risk of developing it. These are:
The risk of developing CLL increases with age. Most people diagnosed with CLL are aged over 60. It is rare in people under 40.
CLL is more common in men than women.
Most people with CLL have no family history of it. But studies show that there is an increased risk of developing CLL if you have a close relative who has it. A close relative is a parent, sibling, or child. If anyone else in your family has CLL, it is important to tell your specialist.
Most people who have a relative with CLL will never develop it themselves.
CLL is not infectious and cannot be passed on to other people.
CLL is most common in people of European origin.
CLL is often diagnosed after a routine blood test, and you may have had no symptoms at all.
The blood tests you may have include:
Immunophenotyping checks for CLL cells in the blood.
Cytogenetic testing looks at all the chromosomes in the leukaemia cells.
Fluorescent in situ hybridisation (FISH) testing
Immunoglobulin testing checks the levels of antibodies you have in your blood for fighting infection.
Direct Coombs test
Direct Coombs test checks if the CLL cells are making antibodies that can damage your red blood cells.
You may also have further tests, such as:
A CT scan takes a series of x-rays, which build up a 3D picture of the inside of the body. A CT scan is sometimes used to check how many lymph nodes are affected by CLL. It can also be used to see whether the spleen is enlarged.
Bone marrow biopsy
Lymph node biopsy
You will not usually need a lymph node biopsy. But some people with CLL may have one. People with small lymphocytic leukaemia may also need a lymph node biopsy. Your cancer doctor or specialist nurse can explain whether this is right for your situation.
An enlarged lymph node or a small section of lymph node is removed so it can be looked at under a microscope. You may have this done under a local or general anaesthetic. It is a small operation and most people can go home on the same day. After the operation, you have a small wound with a few stitches. The stitches are usually taken out after 7 to 10 days.
A team of specialists will meet to discuss the best possible treatment for you. This is called a multidisciplinary team (MDT).
Your cancer doctor or specialist nurse will explain the different treatment options and their side effects. They will also talk to you about certain things to think about when making treatment decisions.
Only a small number of people with CLL need to start treatment straight away. Doctors usually wait until there are signs the CLL is progressing before suggesting you have treatment. This is called monitoring (watch and wait).
Most people who do need treatment are treated with:
- targeted therapy – are a kind of drug therapy used to find and attack leukaemia cells.
- chemotherapy – chemotherapy uses anti-cancer (cytotoxic) drugs to destroy or damage leukaemia cells.
Other treatments that are sometimes used include:
Donor stem cell transplant
We have more information about treatment for CLL.
Follow-up and monitoring CLL
CLL often progresses very slowly. This means that people with CLL can live with it for a long time. If you do need treatment, it is usually very effective and can keep the leukaemia under control for many years. You will need to have regular check-ups and blood tests. You may attend the hospital for these, or they may be done by your GP.
If you have any problems or notice any new symptoms, tell your doctor as soon as possible. Do not wait until your next appointment.
You may want to find out more about having a healthier lifestyle. This will help you stay as well as possible. Some examples of having a healthy lifestyle include:
- having a well-balanced diet
- being physically active
- reducing stress
- being involved in your healthcare.
There are many benefits of having a healthy lifestyle. It does not have to be difficult or expensive. You could try going for a daily walk or doing some exercises at home. This will improve your health and well-being, and lower your risk of getting other illnesses and some cancers.
When planning changes, you need to consider how the side effects of treatment might affect you. Try not to do too much, too soon.
Understanding more about CLL and its treatment can also help you cope. It can help you talk to your doctors and nurses about your treatment, tests and check-ups. It can also help you be involved in making decisions. This can make you feel more confident and give you back a feeling of control.
Get involved in your healthcare
This includes taking your medicines as prescribed and always going to your hospital appointments. If you have any problems or notice any new symptoms between appointments that do not go away within a couple of weeks, tell your doctor as soon as possible.
Self-help and support groups
Everyone has their own way of dealing with illness and the different emotions they experience. You may find it helpful to talk things over with family and friends or your doctor or nurse.
The organisations below offer information and support:
- Anthony Nolan
Anthony Nolan is the UK’s largest stem cell and bone marrow register.
- Chronic Lymphocytic Leukaemia Support Association
The Chronic Lymphocytic Leukaemia Support Association supports CLL patients, their families and their carers through education and access to reliable, relevant and current information.
- Blood Cancer UK
Blood Cancer UK is a blood cancer research charity that provides information and support on any type of blood cancer.
Macmillan is also here to support you. If you would like to talk, you can:
Below is a sample of the sources used in our chronic lymphocytic leukaemia (CLL) information. If you would like more information about the sources we use, please contact us at email@example.com
Schuh A et al. Guideline for the treatment of chronic lymphocytic leukaemia. British Society for Haematology Guidelines. July 2018.
Eichhorst B et al. Chronic lymphocytic leukaemia: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. ESMO Guidelines Committee. October 2020.
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editor, Dr Anne Parker, Consultant Haematologist.
Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.
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