Chronic Myelogenous Leukaemia (AML), also known as Chronic Myeloid Leukaemia can be defined as a rare form of cancer affecting the blood and bone marrow (the spongy tissue within the bones which synthesises blood cells). The term ‘Chronic’ in the name of the disease refers to the slow progression of blood cancer whereas the term ‘myeloid or myelogenous’ indicates the type of cells that are affected by malignancy. The myeloid cells usually develop into mature blood cells that synthesise RBC, WBC and platelets. Due to leukaemia, the myeloid bone marrow cells do not grow naturally but metastasize into immature blood cells known as blasts.
CML is also known by other medical terms including chronic myeloblastic leukaemia, chronic granulocytic leukaemia and chronic non-lymphocytic leukaemia.
Also Read: Blood Cancer / Leukaemia: Causes, Symptoms And Treatment
What Causes Chronic Myeloid Leukaemia?
Similar to other types of cancer, the exact cause of Chronic Myeloid Leukaemia is yet to be discerned. But scientific case studies indicate that CML primarily occurs due to acquired genetic mutation in the DNA of the developing bone marrow cells. The acquired mutated or changed genes then give the bone marrow cells new instructions on what to do. In this case, the acquired mutation creates a new fused gene, BCR-ABL which triggers the myeloid stem cells in the bone marrow to synthesise an abnormal version of tyrosine kinase enzymes. With time, the abnormal myeloid stem cells in your bone marrow start dividing and multiplying uncontrollably, making unusually large amounts of immature white blood cells (myeloblasts) which are unable to function properly like the healthy ones, and usually grow abnormally in size and number, amassing gradually to form tumorous structures. CML can also arise due to extended exposure to certain chemicals or chemotherapy medications.
Also Read: Acute Myeloid Leukaemia: Causes, Symptoms And Treatment
Risk Factors
Certain causative factors that aggravate the risk of CML include:
Age: Although it can happen in anyone, people aged 65 years or older are more at risk of Chronic myeloid leukaemia
Gender: Men are more at risk of getting diagnosed with Chronic myeloid leukaemia than women
Other Blood Disorders: Individuals who are suffering from or have had other blood disorders like myelodysplasia, myelofibrosis, polycythemia vera or thrombocythemia, in the past are more prone to CML
Chemicals: Long-term exposure to certain chemicals, like benzene, pesticides, detergents, or paint strippers, may increase the incidence of Chronic myeloid leukaemia.
Radiation: Susceptibility to high levels of radiation makes a person more prone to CML
Previous Cancer Treatment: People who have been subjected to certain types of chemotherapy and radiation therapy in the past owing to some other types of cancer have an aggravated risk of developing CML
Genetic Factors: Certain genetic disorders, such as Neurofibromatosis type 1, Trisomy 8, Down’s syndrome, or Li-Fraumeni syndrome makes one more susceptible to Chronic Myeloid Leukaemia
Smoking: Smoking and consumption of tobacco in any form aggravates the chances of getting diagnosed with Chronic Myeloid Leukaemia
Symptoms
Although the primary symptoms of Chronic Myeloid Leukaemia often get unnoticed as they mimic those of a common cold or flu, the most common signs and symptoms include:
- Fever
- General Fatigue
- Bone pain
- Headaches
- Shortness of breath
- Pale skin
- Frequent bruising and bleeding
- Frequent nosebleeds and bleeding from the gums
- The appearance of tiny red spots on your skin (i.e., petechiae)
- Easy bleeding
- Feeling full even after consuming a small amount of food
- Loss of appetite
- Pain below the ribs on the left side
- Night sweats
- Swollen liver or spleen
- Weight loss without any cause
Complications
People with CML are often prone to other types of cancer (secondary cancers) including:
- Lung cancer
- Prostate cancer
- Small intestine cancer
- Thyroid cancer
- Stomach cancer
Diagnosis And Treatment
If you find any of the above-stated signs and symptoms staying longer than a normal viral infection, do speak with a doctor right away to get diagnosed at the earliest. The doctor primarily does a thorough physical checkup, apprehends the patient’s medical and genetic history, and conducts the following diagnostics:
- Complete Blood Test
- Bone Marrow Test
- Imaging procedures like X-rays, CT-scan, MRI-scan and Ultrasounds
- Lumbar Puncture (spinal tap)
- Genomic Testing
- Biopsy
Phases Of Chronic Myelogenous Leukaemia
The phase of chronic myelogenous leukaemia usually indicates the aggressiveness of the disease. The oncologist determines the phase of CML by measuring the proportion of malignant cells to healthy cells in your blood or bone marrow.
The stages of CML include:
Chronic: The chronic phase is the initial stage of CML that has lesser malignant cells than healthy cells and generally has the best response to treatment.
Accelerated: The accelerated phase is a transitional phase of CML which has approximately the same proportion of healthy and malignant cells. It is the phase when the disease gradually becomes more aggressive.
Blast: The Blast phase is an advanced, severe phase of CML that has a very higher proportion of malignant cells than the healthy ones making it a life-threatening stage.
Treatment
Although this type of blood cancer is a slow-growing one, it is still necessary to treat it right away as it can often complicate secondary cancers. The available treatment options conducted in the above phases include:
- Targeted drug therapy
- Bone marrow transplant
- Chemotherapy
- Clinical trials
