Most blood cells in the body develop from cells in the bone marrow – the spongy material in the center of the bones — called stem cells. Stem cells mature into different kinds of blood cells, each with its own special job: White blood cells help fight infection, red blood cells carry oxygen to tissues throughout the body, and platelets help form blood clots to control bleeding. These blood cells are created as the body needs them.
Normally, when cells grow old or get damaged, they die, and new cells take their place. However, sometimes this process can go wrong. Cells do not grow and divide normally, or the immune system goes haywire and attacks normal tissue.
Blood cancer is an umbrella term for cancers that affect the blood, bone marrow and lymphatic system.
Unfortunately, blood cancer affects a large number of people. Every 20 minutes, someone in the UK is told they have a blood cancer. That’s 70 people a day, 25,000 people a year.
Three main groups of blood cancer
Some types are more common than others:
- Non-Hodgkin lymphoma is the sixth most common cancer in the UK
- Leukaemia is the eleventh most common cancer in the UK
- Other types of blood cancer – such as myeloma – are less common.
Find out more about types of blood cancer and their treatments:
- Myelodysplastic syndromes (MDS)
Leukaemia affects your white blood cells. These are an important, infection-fighting part of your immune system, made in your bone marrow.
If you have leukaemia, you produce an abnormal number of immature white blood cells which ‘clog up’ your bone marrow and stop it making other blood cells vital for a balanced immune system and healthy blood.
Acute leukaemia comes on suddenly, progresses quickly and needs to be treated urgently. Chronic leukaemia develops more slowly, over months or years.
Four main types of leukaemia:
- Acute myeloid leukaemia (AML). It affects around 2,600 adults a year in the UK. It’s most common in people over 65, although people of any age can get it.
- Acute lymphoblastic leukaemia (ALL). This is the most common type of leukaemia in children. ALL affects around 650 people a year in the UK. About half the cases are in adults and half in children.
- Chronic myeloid leukaemia (CML). It’s also quite a rare condition: only about 700 people every year are affected.
- Chronic lymphocytic leukaemia (CLL). Doctors diagnose just over 3,200 people with CLL a year in the UK. It’s much more common to get it if you’re over 60 and is very rare in people under 40.
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 is a type of blood cancer that affects your lymphatic system, an important part of your immune system which helps to protect your body from infection and disease.
If you have lymphoma it means you make too many lymphocytes, a type of white blood cell. Your lymphocytes also live longer than they should. This overload compromises your immune system.
Lymphoma can develop in many parts of your body, including your lymph nodes, bone marrow, blood, spleen and other organs.
Types of lymphoma
- Non-Hodgkin lymphoma (NHL). Most lymphomas are NHL – it’s the sixth most common cancer in the UK. Each year, around 12,000 people are diagnosed with it in the UK. It’s more common in older people – 1 in 6 (60%) people diagnosed with NHL are over 65.
- Hodgkin lymphoma (used to be called Hodgkin disease). This is less common, and makes up less than 1% of all cancers in the UK. Around 1,800 people a year are diagnosed with Hodgkin lymphoma. Hodgkin lymphoma can develop at any age, but it’s most common in young adults and in older men and women.
Myeloma (also called multiple myeloma) is a blood cancer of the plasma cells. Plasma cells are found in your bone marrow and produce antibodies which help fight infection.
In myeloma, unusually large numbers of abnormal plasma cells gather in your bone marrow and stop it producing an important part of your immune system.
In the UK, just under 4,800 people are diagnosed with myeloma each year. The risk of myeloma increases as you get older – about 4 out of 10 (40%) of cases are in people aged over 75.
Myelodysplastic syndromes (MDS)
The myelodysplastic syndromes (MDS) are a group of blood disorders where a person’s bone marrow is not producing the correct amount and quality of blood cells. Red, white and platelet cells can be affected.
These problems lead to people with MDS feeling very tired, weak and bleeding or bruising more easily. There are different levels of severity of MDS, it’s not a type of leukaemia but can sometimes lead to acute myeloid leukaemia. MDS is rare – about 4 in every 100,000 people get MDS.
It mainly affects older people, and is more common in people over 70 years old.
If you have low or intermediate risk MDS you may not need treatment straightaway, but regular blood transfusions and medication can help. Some people with more severe MDS can have chemotherapy and a small number of people may need to have a stem cell transplant
Treatments for blood cancer
When it comes to deciding on the best treatment, it all depends what type of blood cancer you have, how advanced and aggressive it is and your general health. Your doctor will suggest the most effective course of treatment for you.
Common treatments are chemotherapy, radiotherapy and, in some cases, a stem cell or bone marrow transplant.
What is chemotherapy?
Chemotherapy involves taking drugs that destroy cancer cells, hopefully putting it into remission or significantly slowing down the progression of the disease.
There are many types of chemotherapy drugs and they work in different ways. Sometimes doctors will prescribe a single drug, but often they’ll recommend combining two or more because they often work better together.
Chemotherapy can be used on its own, but it’s often combined with other treatments like radiotherapy. Chemotherapy is designed to attack cells that are growing and multiplying. That’s because cancer cells grow and multiply faster than healthy cells.
Some healthy cells can be caught in the crossfire, as they can also be growing and dividing quickly. This can cause side effects such as nausea, tiredness and hair loss.
If you’re getting ready for a stem cell, bone marrow or cord blood transplant, you’ll also need chemotherapy to suppress your immune system and stop it attacking your donor’s new ‘foreign’ cells. This is called conditioning therapy.
What is radiotherapy?
Radiotherapy works by using high-energy X-rays to kill cancer cells.
For it to be effective, doctors need to give just the right amount of radiation, targeted at the right area of the body. That’s why you get radiotherapy in specialist centres where doctors, physicists and radiographers work together. They’ll normally use a machine called a ‘linear accelerator’ for the treatment.
Radiotherapy can treat some types of leukaemia and lymphoma. Doctors can also use it to prepare a patient for a stem cell, bone marrow or cord blood transplant as part of the conditioning therapy.
A low dose of radiation will lower someone’s immune system, so they’re less likely to reject donor cells.
The type of radiotherapy you might have before a stem cell transplant is called total body irradiation or TBI and this means it affects the whole body.
Radiotherapy can also damage normal cells, which can cause side effects. These vary greatly for each person; some experiencing mild symptoms such as tiredness while for others it can be more debilitating.
These side effects will normally have passed within a few weeks of the treatment finishing.
When radiotherapy finishes, most of your body’s healthy cells will continue to grow normally again. But radiotherapy can have long-term side effects.