What is Leukaemia (Blood Cancer)?
Leukeamia is a type of cancer that affects the blood and bone marrow. Normally all blood cells are produced by the bone marrow (the spongy area in the middle of bones) in a controlled fashion. All leukaemias have in common property that the leukaemia cells are abnormal and do not respond to normal control mechanisms. Large numbers of leukaemia cells build up as they multiply or because they live much longer than normal cells, or both. With many leukaemia cells in the bone marrow, they spill out into the bloodstream.
If you develop leukaemia it is important to know exactly what type it is. This is because the outlook (prognosis) and treatments vary for the different types.
What are common types of Leukaemia?
The four most common types of leukaemia are:
- Acute Myeloid Leukaemia (AML)
- Acute Lymphoblastic Leukaemia (ALL)
- Chronic Myeloid Leukaemia (CML)
- Chronic Lymphocytic Leukaemia (CLL)
Each main type of leukaemia is named according to the type of cell that is affected (a myeloid cell or a lymphoid cell) and whether the disease begins in mature or immature cells. People can get leukeamia at any age. It is most common in people over age 60. The most common types in adults are AML and CLL. ALL is the most common form of leukaemia in children.
What causes Leukaemia?
In most cases of leukaemia, the reason why a cell becomes abnormal is not known. There are certain risk factors which increase the chance that certain leukaemia will develop, but these only account for a small number of cases. Risk factors for some types of leukaemia include:
- Radiation: Previous radiotherapy for another condition. Many of the survivors of the atom bomb used in World War II developed leukaemia due to the fall out of radiation
- Past treatment with chemotherapy or other drugs that weaken the immune system
- Certain genetic disorders e.g. Down’s syndrome
- Exposure to certain chemicals, such as benzene
What are the signs & symptoms of Leukaemia?
As large numbers of abnormal blood cells are made, much of the bone marrow fills with these abnormal cells. Because of this, it is difficult for normal cells in the bone marrow to survive and produce enough normal mature blood cells. Also, the abnormal cells spill out into the bloodstream.
Therefore, the main problems which can develop include:
- Tiredness or no energy
- Shortness of breath during physical activity
- Pale skin
- Mild fever or night sweats
- Slow healing of cuts and excess bleeding
- Black-and-blue marks (bruises) for no clear reason
- Pinhead-size red spots under the skin
- Aches in bones or joints (for example, knees, hips or shoulders)
- Low white cell counts, especially monocytes or neutrophils
Also, there are a reduced number of normal white blood cells which usually combat infection. Therefore, serious infections are more likely to develop. Depending on the type and site of infection which develops, the symptoms can vary greatly.
The time taken to develop these symptoms after the disease starts varies. Typically, it is within weeks for ALL or AML. It may take months or years for symptoms to develop with CLL or CML as these leukaemias progress slowly.
How is Leukaemia diagnosed and assessed?
A CBC (Complete Blood Count) is used to diagnose leukaemia. This blood test may show high or low levels of white cells and show leukaemia cells in the blood. Sometimes, platelet counts and red cell counts are low.
Bone marrow tests (aspiration and biopsy) are often done to confirm the diagnosis and to look for chromosome abnormalities. These tests identify the leukaemia cell-type. For this test a small amount of bone marrow is removed by inserting a needle into the pelvis bone. Local anaesthetic is used to numb the area. A small sample of bone may also be taken.
Lumbar puncture is a test to collect a small amount of fluid from around the spinal cord, i.e., Cerebrospinal Fluid (CSF). It is done by inserting a needle between the vertebrae in the lower (lumbar) region of the back. By examining the fluid for leukaemia cells, it helps to find out if the leukaemia has spread to the brain and spinal cord. This is mainly done when assessing ALL and sometimes AML.
What is the treatment for Leukaemia?
It is important to get medical care at a centre where doctors (Haematologist) are experienced in treating patients with leukaemia. The aim of leukaemia treatment is to bring about a complete remission. This means that after treatment, there is no sign of the disease and the patient returns to good health.
The treatment advised depends on the exact type of leukaemia, and the stage it is at. For example, ALL/AML is usually treated as soon as possible with intensive chemotherapy. On the other hand, people in the early stages of CLL may not need any treatment. This is because CLL often progresses very slowly and may not need treatment for several years.
Acute Leukemia (AML or ALL)
Treatment for patients with acute leukaemia may include chemotherapy, stem cell transplantation. In these patients, treatment need to start soon after diagnosis.
Usually, treatment is begun with chemotherapy, which is often given in the hospital. The first part of treatment is called induction therapy. More inpatient treatment is usually needed even after a patient is in remission. This is called post-remission therapy and consists of consolidation (intensification) therapy, and in some cases, maintenance therapy. This part of treatment may include chemotherapy with or without stem cell transplantation (sometimes called bone marrow transplantation).
Chronic Leukemia (CML or CLL)
Patients with CML need treatment soon after diagnosis which is oral chemotherapy on outpatient basis. There are three drugs approved for newly diagnosed patients. These drugs are imatinib, dasatinib and nilitinib. Allogeneic Stem Cell Transplantation is another treatment option that is only done if CML is not responding as expected to the drug therapy.
Some CLL patients do not need treatment for long periods of time after diagnosis, sometimes called watch and wait. Patients who need treatment may receive chemotherapy or monoclonal antibody therapy alone or in combination. Allogeneic stem cell transplantation is a treatment option for certain patients, but usually not as the first choice of therapy.
Side effects of treatment
Patients react to treatments in different ways. Usually they have mild side effects. Many treatment side effects go away when treatment ends or becomes less noticeable over time. Most can be handled without the need to stop the drug. Other side effects may be serious and lasting.
Common side effects may include
- Changes in blood counts
- Mouth sores
- Stomach upset
- Extreme tiredness
- Hair loss
What is role of stem cell transplant in treatment of Leukaemia?
Allogenic Haematopoietic Stem Cell Transplant, where stem cells are taken from HLA matched donor, is offered first line as consolidation in intermediate & high risk patient. AML patient and high risk ALL patients. It is also best treatment for any relapsed leukaemia. CML patient who progressed or presented in higher stage is also a candidate for allogenic bone marrow transplant. Some of the young CLL patients or those with resistant or high risk CLL are also offered treatment with Stem Cell Transplant.
What is the outlook (prognosis)?
The outlook varies for each of the different leukaemias. However, the overall outlook may be better than many people imagine. For example, the outlook for ALL has greatly improved over the last 20 years or so. Most children with ALL (about 7-8 in 10 cases) can be cured. Also, the chronic leukaemias (CLL and CML) often progress slowly - often over several years. Even in those cases which are not cured, treatment with chemotherapy and other treatments can often prolong survival for quite some time.
Follow up care is important with all forms of leukaemia because, even if the disease recurs, curative options are still available for many people. AML, ALL, CML and CLL patients who are in remission need to see their doctors regularly for exams and blood tests. Bone marrow tests may be needed from time to time. The doctor may recommend longer periods of time between follow-up visits if a patient continues to be disease free. Each type of leukaemia may be followed differently. Speak to your doctor to find the best care plan for you.