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 Myeloid Leukaemia (CML)
Myeloid cells, in particular granulocytes
788 / year in the UK
61 in 2019
More common in people over 65
Tyrosine Kinase Inhibitors (TKI) and possibly a stem cell transplant
TKIs allow most CML patients to live long and healthy lives
CML and stem cell transplants
Most patients with CML are diagnosed during the chronic phase, when treatment with a type of drug called Tyrosine Kinase Inhibitors (TKIs) is possible. Some TKIs are designed to stop cancer cells growing by targeting the Philadelphia Chromosome.
Stem cell transplants are only recommended:
- if you have CML that hasn’t responded to TKIs, or
- if you are diagnosed with ‘blast crisis’ CML and treatment gets you back to ‘chronic’ phase CML.
If you do need a transplant, it will be an allograft transplant – when stem cells are donated to you by someone else.
Living with CML
Many more patient stories are available in our Blogs section
Information published: 11/02/21
Next review due: 11/02/24