Leukaemia is cancer of the white blood cells. Chronic leukaemia tends to progress slowly over the course of many years.
Normal white blood cells contribute to the body's defence against infection. Chronic leukaemia is classified according to the type of white blood cells affected by cancer. There are two main types:
- chronic lymphocytic leukaemia
- chronic myeloid leukaemia
These pages focus on chronic lymphocytic leukaemia, which affects a type of white blood cell called lymphocytes.
On this site you can also find information on chronic myeloid leukamia.
Warning signs of chronic leukaemia
In its early stages, chronic lymphocytic leukaemia usually causes no noticeable symptoms. As the condition develops, symptoms include:
- repeated infections (that occur over a short space of time)
- swollen lymph nodes (glands)
Read more information about the symptoms of chronic lymphocytic leukaemia.
What happens in chronic leukaemia
All of the blood cells in the body are produced by bone marrow. Bone marrow is a spongy material found inside the bones. It is important because it produces special cells called stem cells.
Stem cells are very useful because they have the ability to create other specialised cells that carry out important functions. The stem cells in bone marrow produce 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
In leukaemia, the cancer begins in the stem cells and causes them to produce more of a particular type of white blood cell at the expense of normal bone marrow cells.
This means that the body does not have enough red blood cells or platelets. This can cause symptoms of anaemia, such as tiredness, as well as increasing the likelihood of excessive bleeding.
Also, as the white blood cells are not properly formed, they are less effective at fighting bacteria and viruses, making you more vulnerable to infection.
How common is chronic lymphocytic leukaemia?
Chronic leukaemia is relatively common type of cancer.
Chronic lymphocytic leukaemia is more common in older people, with most cases developing in people over the age of 55.
It can be cured using a bone marrow transplant. However, this is dependent on the age of the patient (transplantation carries too many risks for more elderly patients) and finding a suitable donor.
The outlook for patients with chronic lymphocytic leukaemia varies depending on the stage of the cancer at diagnosis and how well the patient responds to treatment.
For the majority of patients, a diagnosis of chronic lymphocytic leukaemia does not mean that treatment is required immediately.
Read more information about the treatment of chronic lymphocytic leukaemia.
There are some cases where chronic lymphocytic leukaemia does not affect a person's natural life span.
In its early stages, chronic lymphocytic leukaemia usually causes no noticeable symptom
As the condition develops, symptoms include:
- repeated infections (that occur over a short space of time)
- night sweats
- unusual bleeding and bruising
- swollen spleen
- swollen lymph nodes (glands)
Chronic lymphocytic leukaemia is an acquired genetic disease. Normal blood cells acquire changes to their genes that make them grow out of control.
There may be certain genes within your family that make you more likely to develop chronic lymphocytic leukaemia. However, if you have the disease, it isn't possible to predict whether any of your family will get it too.
What triggers the development of chronic leukaemia and causes the initial mutations is unknown.
Chronic lymphocytic leukaemia (CLL) has a genetic basis. For example, some families have a higher-than-expected incidence of chronic lymphocytic leukaemia, which suggests that a susceptibility to the condition runs in families. Exactly which genes are linked to CLL is still uncertain.
Several occupations are associated with a slightly higher risk of chronic lymphocytic leukaemia, possibly due to certain substances such as pesticides or chemicals. These occupations include agricultural work and rubber or plastic manufacture.
Nowadays, chronic lymphocytic leukaemia is often diagnosed on a blood count that may have been carried out for a reason not connected to the leukaemia. The leukamia may be at such an early stage that it does not cause symptoms.
The blood count will show an abnormally high number of lymphocytes (a type of white blood cell). This may have several causes and to make a definite diagnosis, your doctor will do a special test called immunophenotyping. This test characterises the lymphocytes in great detail and will distinguish chronic lymphocytic leukaemia from other conditions that may cause a high lymphocyte count.
Once a diagnosis has been made, you will be referred to a haematologist (a specialist in treating blood conditions) for further diagnostic tests and to discuss the implications of the diagnosis.
There are a number of additional tests that can be used to help reveal more information about the progress and extent of the leukaemia. They can also provide an insight into how the leukaemia should be treated. These tests are described below.
Bone marrow biopsy
To confirm a diagnosis of chronic leukaemia, the haematologist will take a small sample of your bone marrow to examine under a microscope. This is known as a bone marrow biopsy. A bone marrow biopsy is usually carried out under a local anaesthetic.
The haematologist will numb an area of skin at the back of your hip bone, before using a needle to remove the bone marrow sample. The procedure is usually painless although you may experience some bruising and discomfort for a few days afterwards. The procedure takes around 15 minutes to complete and you should not have to stay in hospital overnight.
The bone marrow sample will be checked to see if there are cancerous cells. If there are, the biopsy will also be able to help determine which type of chronic leukaemia is present.
Cytogenetic testing involves identifying the genetic make-up of the cancerous cells. There are several specific genetic variations that can occur during leukaemia and knowing what these variations are can have an important impact on treatment.
Lymph node biopsy
If you have been diagnosed with chronic leukaemia, further biopsies may be carried out on any enlarged lymph nodes that you have. These are to see how far the leukaemia has spread.
If you have chronic leukaemia, a computerised tomography scan (CT scan) may be used to check that your other organs, such as your heart and lungs, are healthy.
Most patients diagnosed with chronic lymphocytic leukaemia will have no symptoms. For such patients, there is no advantage (in terms of overall survival) in starting treatment.
This is because all current treatments involve chemotherapy and, because of their associated side effects, treatments are only recommended when a patient experiences one or more of the following:
- develops symptoms
- has diseased lymph nodes
- has very rapidly rising numbers of lymphocytes (white blood cells) in their bloodstream
For patients without symptoms, a policy of "watchful waiting" is recommended. This means regular blood tests and visits to the doctor, so the progress of the condition can be carefully monitored.
Treating advanced chronic lymphocytic leukaemia
There is a large amount of variability in the development of chronic lymphocytic leukaemia:
- In some patients the disease may remain at a low level, for which treatment is not required for many years (possibly decades).
- For some patients, especially those with particular genetic abnormalities, the disease may progress within a few months.
- Some patients may be well for several years but then develop symptoms.
Most patients will be fit enough for modern chemotherapy programmes (if they come to need treatment), although if there are pre-existing heart or kidney conditions, the haematologist may modify the doses that are administered.
Chemotherapy tablets are the main treatment, and the monoclonal antibody rituximab is usually also given as part of the standard treatment programme. Some patients will need a different monoclonal antibody, called campath.
There are many clinical trials using new drugs, many of which are not based on chemotherapy, and these trials may change standard treatments in a few years.
The standard treatment programme is currently fludarabine, cyclophosphamide(all types)and rituximab (FCR). Fludarabine and cyclophosphamide are usually given in tablet form to be taken for five days every 28 days.
FCR benefits most patients, and in some the remissions may be several years, but this treatment programme is probably not capable of curing the disease.
All chemotherapy can weaken the immune system (known as being immunocompromised), and this is one of the most serious consequences of chemotherapy because it can lead to serious infections.
Patients receiving FCR will be prescribed antibiotics during the course of their treatment to try to prevent infections. Read more information about the complications of chronic lymphocytic leukaemia.
Rituximab is a monoclonal antibody. Monoclonal antibodies are genetically engineered in a laboratory.
Rituximab works by targeting a protein found on the surface of the chronic lymphocytic leukaemia cells, which causes them to be destroyed by the immune system.
Rituximab is given intravenously over the course of several hours. This is known as an infusion.
Common side effects of rituximab include:
- flu-like symptoms, such as chills and a high temperature, while the medication is being given
- reactions at the place where it enters the vein
Most infusion reactions occur within 24 hours of the first time that someone begins treatment. It is likely you will be closely monitored once your treatment begins.
If you start to experience the symptoms of an infusion reaction, such as shortness of breath or chest pain, anti-allergy medicines such as corticosteroids can be used to help relieve your symptoms.
Campath is another monoclonal antibody that binds to a different surface protein to that targeted by rituximab. Its use may be considered in two situations:
- for patients who have genetic markers associated with disease that has a very poor clinical outcome
- if treatment with FCR is not successful
There is interest in combining campath with other agents, particularly steroids. Campath infusions can weaken the immune system, so patients will be prescribed antibiotics while on this treatment.
A new medication for chronic lymphocytic leukaemia is called bendamustine.
Bendamustine is given by infusion, two times a week every four weeks. This cycle of treatment may then be repeated up to six times. The most serious side effect of bendamustine is a weakened immune system.
Bone marrow and stem cell transplants
The only available cure for chronic lymphoblastic leukaemia is to have a bone marrow or stem cell transplant.
Before transplantation can take place, the person receiving the transplant has to have aggressive, high-dose chemotherapy and radiotherapy to destroy any cancerous cells in their body.
This can put enormous strain on the body and can cause significant side effects and potential complications. Transplantations have better outcomes if the donor has the same tissue type as the person who is receiving the donation. The best candidate to provide a donation is usually a brother or sister with the same tissue type.
Due to these issues, transplantations are usually only successful when they are carried out in children and young people, or older people in good health, and there is a suitable brother or sister who can provide a donation.
In most cases of chronic lymphocytic leukaemia, the potential risks of transplantation far outweigh any benefit. For example, the chances of an elderly person with advanced chronic leukaemia surviving a bone marrow transplant can be as low as one in five.
However, your individual circumstances may mean that the benefits of treatment outweigh the risks.
Read more about bone marrow transplants.
There are potential complications of chronic lymphocytic leukaemia, and complications associated with the treatments given.
Complications of chronic lymphocytic leukaemia
In 5% or fewer of patients with chronic lymphocytic leukaemia, the disease will change to become very similar to an aggressive form of non-Hodgkin's lymphoma. This is called Richter's transformation or Richter syndrome.
Symptoms of Richter syndrome include:
- sudden swelling of your lymph nodes
- a high temperature that is not caused by infection
- night sweats
- weight loss
- abdominal pain
Richter syndrome is treated with a combination of chemotherapy and rituximab. Find out more about Richter syndrome.
Autoimmune haemolytic anaemia
About 10% of patients with chronic lymphocytic leukaemia will develop anaemia as a result of their red blood cells breaking down. The cause is the production of an antibody that targets and destroys the patient’s red cells.
The anaemia can be severe and cause the patient to become easily tired or breathless. Autoimmune haemolysis is treated mainly with steroids, although other agents may also be used.
Receiving a diagnosis of chronic leukaemia can be very distressing, particularly if it is unlikely that your condition can be cured. At first, the news may be difficult to take in.
The situation can be made worse if you are confronted with the knowledge that even though your leukaemia may not currently be causing any symptoms, it could be a serious problem in later life. Having to wait many years to see how the leukaemia develops can be immensely stressful and can trigger feelings of anxiety and depression.
If you have been diagnosed with leukaemia, talking to a counsellor or psychiatrist (a doctor who specialises in treating mental health conditions) may help you to combat feelings of depression and anxiety. Antidepressants or medicines that help to reduce feelings of anxiety may also help you cope better with the condition.
You may find it useful to talk to other people who are living with leukaemia. Your doctor or care team may be able to provide you with details of local support groups.
Complications of treatment
Weakened immune system
Being immunocompromised (having a weakened immune system) is a common complication of chronic leukaemia.
There are two reasons for this:
- The lack of healthy white blood cells means that your immune system is less able to fight infection.
- Many of the medicines used to treat chronic leukaemia can weaken the immune system.
This means that you are more vulnerable to developing an infection, and that any infection you have has an increased potential to cause serious complications.
You may be advised to take regular doses of antibiotics to prevent infections occurring. Immediately report any possible symptoms of an infection to your doctor or care team because prompt treatment may be required to prevent serious complications.
Symptoms of infection include:
- high temperature of 38C (101.4F) or above
- aching muscles
Patients should avoid contact with anyone known to have an infection, even if it is a type of infection to which they were previously immune, such as chickenpox or measles. This is because their previous immunity to these conditions will probably be suppressed (lowered).
While it is important to go outside on a regular basis, both for exercise and general wellbeing, patients should avoid visiting crowded places and using public transport during rush hour.
Patients should also ensure that all of their vaccinations are up-to-date. Your doctor or care team will be able to advise about this. Patients will be unable to have any vaccine that contains activated particles of viruses of bacteria such as:
- the mumps, measles and rubella (MMR) vaccine
- the polio vaccine
- the oral typhoid vaccine
- the BCG vaccine (used to vaccinate against tuberculosis)
- the yellow fever vaccine
Many treatments used to treat chronic leukaemia can cause infertility. Infertility is often temporary, although in some cases it may be permanent.
The treatment team will be able to provide a good estimation of the risk of infertility in your specific circumstance.
It may be possible to take steps to guard against any risk of infertility before beginning treatment. Men can have samples of their sperm stored so that it can be used to implant an embryo later. Women can occasionally have fertilised embryos stored, which can then be placed back into the womb after treatment.
Read more about infertility.