CML stands for chronic myeloid leukaemia, and it is a type of slow blood cancer. This cancer starts in the blood-forming cells of the bone marrow and invades the blood. In CML, leukaemia cells tend to build up in the body over time, but in many cases people don’t have any symptoms for at least a few years. With time, these cells invade other parts of the body, including the spleen. CML can also change into a fast-growing form known as acute leukaemia which is capable of invading any organ in the body. Most people with CML have Philadelphia chromosome – a gene mutation wherein chromosome 9 and chromosome 22 are interchanged.
Chronic Myeloid Leukaemia (CML) is the most common adult leukaemia in India that affects people between the age groups of 30 and 60. It is more common in males than in females with almost 0.8 to 2.2 males out of 100,000 being diagnosed every year. With these startling statistics, it is about time people woke up to the possibility of contracting this disease. Dr Shyam Agarwal, senior consultant at Sir Ganga Ram Hospital, New Delhi, tells us more about the most common form of blood cancer in adults.
Causes
The exact cause of CML is not known, but the patient usually comes to us with symptoms like –
- An enlarged spleen
- Left-sided abdominal pain
- Weakness
- Low grade fever
- Loss of appetite
- Loss of weight
On further testing we find their white blood cell count or total lymphocyte count is raised to a great extent, which is one of the hallmarks of this condition. On further testing we find what is called the ‘Philadelphia chromosome’. Here, chromosome 9 and chromosome 22 are interchanged, because of which, the person’s genes don’t function properly. This leads to the rearrangement of two genes known as BCR and Abl1 gene. Because of this rearrangement the white blood cells within the patient’s bone marrow begins to reproduce abnormally leading to the manifestation of symptoms.
Read more about causes, symptoms, diagnosis and treatment of blood cancer.
Symptoms
One of the most common symptoms is the enlargement of the spleen, low-grade fever and weakness. Bruising as seen in other forms of this disease can happen in about as low as 10 people in the whole population. One will most commonly find bruising in people suffering from acute leukaemia and not this form of the disease.
These are the hallmarks. One should visit a doctor immediately if they see these symptoms.
Diagnosis
Dr Shyam Agarwal says, ‘The earlier the condition is diagnosed, the better the treatment. In this disease there is a scoring system in which the burden of the disease is estimated. But like I said this condition is due to gene rearrangement, so if we control or block this malfunction then most patients suffering from CML recover, even if it is diagnosed a bit late. ‘
A blood test shows very high white blood cell count. The test can identify the presence of the faulty genes, but to get a proper diagnosis a bone marrow biopsy is necessary.
We usually take a bone marrow aspiration to identify the presence of the Philadelphia chromosome in the bone marrow and confirm the presence of the rearranged BCR gene and Able1 gene by the FISH method (Fluorescence in-situ hybridization) or PCR method (polymerase chain reaction).