What are blood cancers?

The blood is made up of different types of blood cells. Blood cells are made in the bone marrow – a spongy material in the middle of our bones. Normally millions of new blood cells are made every day.

There are three main types of blood cell:

  • red blood cells, which carry oxygen
  • platelets, which help the blood to clot
  • white blood cells, which fight and prevent infection.

Blood cancers develop when blood cells aren’t made properly. Blood cancers include leukaemia, lymphoma and myeloma.

Some other conditions are related to blood cancers. They are similar because blood cells grow in an uncontrolled way, but they usually develop more slowly. They can usually be treated but don’t always need treatment straight away. The main conditions are: 

The blood

Blood is made up of different types of blood cells, which float in a liquid called plasma. Blood cells are made in the bone marrow. This is a spongy material that is found in the middle of our bones, particularly in our pelvis, backbone (spine) and breast bone (sternum). Normally, millions of new blood cells are made every day in the bone marrow. These new blood cells replace old and worn-out blood cells.

All blood cells are made from stem cells (blood cells at their earliest stage of development). There are two types of blood stem cell:

  • lymphoid stem cells, which make a type of white blood cell called lymphocytes
  • myeloid stem cells, which make all other types of blood cell, including red blood cells, platelets and other types of white blood cells.

Blood stem cells in the bone marrow divide and grow to make new blood cells. The new, developing blood cells are called blast cells. They don’t look like fully developed cells and they can’t do the jobs that fully developed (mature) cells do. Usually, blast cells stay in the bone marrow until they have developed into red blood cells, platelets or white blood cells.

When the cells develop, they are released into your blood to carry out different functions:

  • Red blood cells contain haemoglobin (Hb), which carries oxygen from your lungs to all the cells in your body.
  • Platelets are very small cells that help your blood to clot, and prevent bleeding and bruising.
  • White blood cells fight and prevent infection. There are several types of white blood cell. The two most important types are neutrophils and lymphocytes.

The levels of these cells in your blood are measured in a blood test called a full blood count (FBC).


Leukaemia

Leukaemia is a cancer of the white blood cells. People with leukaemia usually have more white blood cells than normal but sometimes may have fewer. These leukaemia cells behave differently from healthy white blood cells.

Leukaemia is named according to the type of white blood cell which is affected and whether it is acute (faster growing) or chronic (slower growing).

There are four main types of leukaemia:


Lymphoma

Lymphoma is a cancer of the lymphocytes. Usually, a lump or tumour forms in one or more groups of lymph nodes, but it can begin in other organs in the body.

There are two main types of lymphoma:

An image of Dr Marcus, a lymphoma specialist.

Diagnosing lymphoma

In this cancer information video, Dr Robert Marcus explains what lymphoma is and how it is diagnosed. Linda, who had non-Hodgkin lymphoma, talks about how she felt when she was told of her diagnosis.

About our cancer information videos

Diagnosing lymphoma

In this cancer information video, Dr Robert Marcus explains what lymphoma is and how it is diagnosed. Linda, who had non-Hodgkin lymphoma, talks about how she felt when she was told of her diagnosis.

About our cancer information videos


Myeloma

Myeloma – also known as multiple myeloma – is a cancer of plasma cells. Plasma cells are a type of white blood cell that make proteins called antibodies. They are part of the immune system and help protect the body against infection.


Related blood conditions

Some other conditions are closely related to blood cancers. They are similar because the cells grow in an uncontrolled way. But they tend to develop more slowly than blood cancers. There may be too many or too few of certain types of blood cells. The cells may be made too quickly and don’t mature properly. These cells come from myeloid stem cells, which are made in the bone marrow. The main conditions are:

ET, PV and MF belong to a group of conditions called myeloproliferative neoplasms (MPNs). This is when the bone marrow makes too many of one or more types of blood cell.

Myelodysplastic syndrome (MDS) is a blood disorder where some of the blood cells made in the bone marrow are damaged. This means that not enough healthy blood cells make it into the bloodstream.

Some people with MPNs and MDS can develop an acute leukaemia.

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Other blood cancers

There are some other conditions that are closely related to blood cancers. These include myeloproliferative neoplasms and myelodysplastic syndromes.