Types of blood cancer
Some of the more common blood cancers and diseases that may need a stem cell transplant are listed below.
Leukaemia is a type of blood cancer that affects blood cells, usually white blood cells, and bone marrow. White blood cells are an important part of your immune system that fight infection, and bone marrow is where blood cells like these are made.
People with leukaemia have large numbers of abnormal blood cells, usually types of white blood cell, which take over the bone marrow and spill out into the bloodstream. Other areas that might be affected are lymph nodes (glands), spleen, liver, testes, the membranes surrounding the brain and spinal cord, gums and skin.
Leukaemia is divided into many different types – some which develop faster (acute leukaemia’s) and others which develop more slowly (chronic leukaemia’s). Each type of leukaemia acts differently, and will need to be treated differently. When you’re looking for information about leukaemia, it really helps to know the proper medical diagnosis so that you can find the right information.
There are four main types of leukaemia
Acute myeloid leukaemia (AML)
Acute myeloid leukaemia (AML) occurs in your bone marrow, when a type of blood cell called a myeloid cell starts growing abnormally and in an uncontrolled way. Normally your blood stem cells develop into myeloid cells, which then become red blood cells, platelets and certain white blood cells (called neutrophils).
If you have AML, your myeloid cells can’t fully mature and they remain as young, immature cells called myeloblasts. These cells divide too quickly which can ‘clog up’ your bone marrow and stop other blood cells from doing their job properly too.
AML is ‘acute’ because it usually develops quickly, sometimes within a few days or weeks. There are different types of AML – your symptoms will depend on the type you have, the number of leukaemia cells in your body, and where they are.
AML can be classified into ‘high’, ‘standard’ and ‘low’ risk – but this only relates to the type of treatment you will be given, not to the chance of it working.
Acute lymphoblastic leukaemia (ALL)
Acute lymphoblastic leukaemia (ALL) is a blood cancer that stops the white blood cells of your immune system growing properly. It involves blood cells called lymphocytes that develop from stem cells in your bone marrow.
Before these cells are fully formed, they’re called lymphoblasts (immature lymphocytes). Your body needs to make new lymphocytes – but when you have ALL, this process doesn’t work properly. Instead, the lymphoblasts grow too quickly and cannot function properly. These cells can also ‘clog up’ your bone marrow and prevent it from making other blood cells.
You will probably hear ALL referred to as either ‘B cell’ or ‘T cell’ ALL. This relates to the type of lymphocyte that is affected, and can help your doctor decide on the best course of treatment.
Some types of ALL are characterised by the ‘Philadelphia Chromosome’, which is also found in chronic myeloid leukaemia (CML). The presence of this genetic alteration enables doctors to give Tyrosine Kinase Inhibitors (TKIs), a targeted treatment that should be effective.
Anybody can get ALL, but it’s the most common type of childhood cancer. It’s an acute condition, meaning symptoms can develop quickly – so it’s very important that treatment is started as soon as possible.
Chronic myeloid leukaemia (CML)
Chronic myeloid leukaemia (CML) affects a type of white blood cell called a myeloid cell. These cells are a middle step between stem cells and fully-formed white blood cells.
People with CML produce too many granulocytes, a specific type of myeloid cell, that are not fully formed. This is why you may hear CML referred to as ‘chronic granulocytic leukaemia’ (CGL). Over time, these abnormal cells fill the bone marrow, which reduces the number of normal cells in the blood.
CML is not classified into different stages, but it does have three recognised phases: ‘chronic’, ‘accelerated’ and ‘blast crisis’. Very few patients progress beyond the chronic phase today due to the effectiveness of modern treatment.
CML is defined by the presence of a ‘Philadelphia Chromosome’ which forms when parts of your DNA are exchanged between two chromosomes. This causes two different genes (called ‘ABL’ and ‘BCR’) that are normally completely separate, to fuse together and promote uncontrolled cell growth.
Chronic lymphocytic leukaemia (CLL)
Chronic lymphoblastic leukaemia (CLL) is a blood cancer that stops the white blood cells of your immune system growing properly. It involves blood cells called B-lymphocytes that develop from stem cells in your bone marrow.
Before these cells mature into lymphocytes, they’re called lymphoblasts (immature lymphocytes). Your body needs to make new lymphocytes – but when you have CLL, this process doesn’t work properly. Instead, the immature cells grow too quickly and cannot function properly. Over time, they accumulate in the lymphatic system and may cause large, swollen lymph nodes. They also fill the bone marrow, reducing the number of normal white blood cells, red blood cells and platelets that can be made.
CLL is a chronic condition that usually develops very slowly – many people don’t need treatment for months or years. However, some people may need to have treatment straight away.
Other types of leukaemia include:
acute promyelocytic leukaemia (APL)
hairy cell leukaemia (HCL)
large granular lymphocytic leukaemia (LGL)
t-cell acute lymphoblastic leukaemia (T-ALL)
chronic myelomonocytic leukaemia (CMML)
Lymphoma affects your immune system and can cause swellings in your neck, armpit, groin, or deeper in your body. There are different types of lymphoma. The symptoms, treatments and prognosis (outlook) depend on which type of lymphoma you have, so if you’ve just found out that you – or someone you know – has lymphoma, it’s useful to know which type it is when you’re looking for information.
The main types are Hodgkin lymphoma and non-Hodgkin lymphoma (NHL). Doctors put non-Hodgkin lymphomas (NHLs) into two groups depending on how fast they develop:
Low-grade NHLs usually develop slowly. The most common type is follicular lymphoma, but other types include marginal cell lymphoma and lymphoplasmacytic lymphoma (which is also called Waldenstrom macroglobulinaemia).
High-grade NHLs usually develop more quickly. The most common type of high-grade NHL is diffuse large B-cell lymphoma (DLBCL), but other types include Burkitt lymphoma and lymphoblastic lymphoma. Most people with lymphoma have non-Hodgkin lymphoma.
Myeloma is a type of cancer that affects plasma cells. A plasma cell is a type of white blood cell, which produces antibodies to fight infection.
When you have myeloma, too many abnormal plasma cells are made in your bone marrow (the spongy tissue inside your bone where your blood cells are made). This also means there isn’t enough room for normal red and white blood cells, which both play an important role in keeping you well.
Usually the bone marrow is affected in a number of places around your body, which is why myeloma is sometimes known as ‘multiple myeloma’. Myeloma is not usually considered a curable disease, but it is very treatable. Many people with myeloma have a good overall quality of life.
Myelodysplastic Syndromes (MDS)
Myelodysplastic syndromes (MDS) are a group of blood disorders that cause your bone marrow to produce too many blood cells. These cells are often unhealthy (dysplastic) and are destroyed soon after leaving the bone marrow. People with MDS feel very tired, weak and bleed or bruise more easily because they cannot produce enough healthy blood cells.
Although MDS are not cancers themselves, they can sometimes develop into acute myeloid leukaemia (AML). All types of MDS are placed into low and high-risk groups based on how likely this is to happen. It also helps your doctor select the most effective treatment option for you.
Aplastic anaemia is a rare condition in which the body stops producing enough new blood cells.Aplastic anaemia develops as a result of bone marrow damage. The damage may be present at birth or occur after exposure to radiation, chemotherapy, toxic chemicals, some drugs or infection.
The main cause of developing aplastic anaemia is after an autoimmune reaction, where your immune system targets your own cells. Symptoms may develop slowly or suddenly. Fatigue, frequent infections, rapid heart rate and bleeding may occur.
Treatment can include medication, blood transfusions and stem-cell transplants.
Sickle cell disease (SCD)
If you have a sickle cell disease (of which sickle cell anaemia is the most severe) your blood is unable to carry oxygen around your body effectively. This is because your red blood cells are an abnormal shape (sickle or crescent-shaped) instead of disc-shaped – so they can’t bind as much oxygen as a normal cell. This will often leave you feeling tired, short of breath and prone to infections.
Sickle cell diseases are genetic. To be affected, both your parents need to have the sickle cell gene. If you get the gene from one parent, you will be a carrier (also known as sickle cell trait), but you won’t have any symptoms. The diseases are more common in people of African and Mediterranean descent.
All autoimmune diseases are caused by an overactive immune system that targets your own cells rather than foreign bodies such as bacteria or viruses. There are over 80 known autoimmune diseases including type I diabetes, rheumatoid arthritis and lupus. Not all autoimmune diseases can be treated with a stem cell transplant, but they can help people with systemic sclerosis and multiple sclerosis, among other conditions.
Although autoimmune diseases are more common in some families, they are not inherited directly (like primary immunodeficiency diseases). They can also be caused by environmental factors, and can sometimes develop after an infection.
If you have thalassemia, you have an abnormal type of haemoglobin – the protein in red blood cells that carries oxygen. This destroys more of your red blood cells than normal, leading to anaemia, which can cause fatigue, headaches and concentration problems. Sometimes it can cause more serious symptoms like shortness of breath.
Thalassaemia is hereditary, meaning that the genes that cause it are passed on from your parents. Roughly 7% of people are thalassaemia carriers (also known as thalassaemia trait) but it’s only passed on to children if both parents are carriers.