What is CML
CML is an abbreviation for Chronic MyeloidLeukaemia.
CML is a cancer of the blood that had an onset over a period of time in which the bone marrow produces immature or abnormal white blood cells.
To understand CML we need to look at the composition and function of blood.
A healthy body produces millions of new blood cells in the bone marrow each day to replace old and worn-out cells.
The blood cells created in the bone marrow are at first immature and all cells look alike, they can also not function as they are intended to. These young cells are called blast cells and they will stay in the bone marrow until they have divided, grown and matured enough to fully function upon which time they are released into the body.
The roles and functions of the different cells include;
Red blood cells contains haemoglobin which carries oxygen from the lungs throughout the body.
Platelets are small cells dedicated to help blood clot and prevent bleeding and bruising.
White blood cellsare responsible in fighting of and preventing infections.
All healthy cells have 23 pairs of chromosomes. Within the chromosome there are various genes that have a “manual” or inherited “instruction” that tells the cell how to function.
CML develops in a young white cell when a piece of chromosome 9 (ABL)switches with a piece of chromosome 22 (BCR).The changed chromosome 22 is called the Philadelphia (Ph) chromosome and is found in most patients with CML. The fusion of the chromosomes also creates a new gene called BCR-ABL .The BCR-ABL gene is formed on chromosome 22 where the piece of chromosome 9 attaches.
The BCR-ABL geneproduces a protein called tyrosine kinase that prevents the new cells in the bone marrow from fully maturing into normal blood cells and also leads to an increase in white cell production.The abnormal cells are called blast cells and soon they “overcrowd” the healthy cells due to an increase in their production.
There are three stages in CML depending on the number of blast cells (unhealthy cells) in your blood.
Signs and symptoms of CML
CML can present itself through various symptoms such as:
• Bone and joint pain
• Enlarges spleen and liver leading to abdominal pain and feeling full even after small meals.
• Fevers, night sweats and weight loss
• Extreme tiredness and fatigue
• Headaches, visual disturbances, hearing loss and confusion
The symptoms can be confused with various other illnesses and this may be the reason why CML is not diagnosed at first.
To confirm a diagnoses of CML the physician would like to confirm the presence of the abnormal Ph Chromosome. A bone marrow aspirate is conducted and tested for the Ph Chromosome. Should the test present a positive result it will also be able to indicate the phase of disease; chronic, accelerated or blast crises.
It is important to understand that CML treatment has been proven to be very effective in cases where patients take their treatment regularly. There is no “quick fix” and treatment is administered over a long period of time with or without some adjustments made along the way.
Most treatments available are aimed at blocking the BCR-ABL protein which should have your white cell count return to within a normal range. These protein blockers are called tyrosine kinase inhibitors (TKI’s). TKI’s (Gleevec, Tasigna, Sprycel) are the most common treatment used in CML to assist the body in producing healthy cells and preventing disease progression.
A stem cell transplant is the only known cure for CML. This treatment requires a donation of stem cells from a donor which could be a family member or unrelated person. Most patients do not require a stem cell transplant due to the effectiveness of the TKI’s.
It is vital that you understand your treatment regime and discuss any uncertainties with your doctor. Take your medication exactly as prescribed. Inform your doctor of any side effects (even if it seems unrelated) and any other diseases you are receiving treatment for. It is also important to speak with your doctor before starting on any new medication, as this may affect how well the TKI works.
During your CML – journey you will undergo various medical test. The most frequent tests conducted will be a CBC (Complete Blood Count) or FBC (Full Blood Count).
To monitor your response to treatment your physician will conduct a polymerase chain reaction test (PCR) to determine the amount of BCR-ABL in your blood.
There are two types of PCR than can be conducted;
1. Qualitative PCR – Can only give a yes/no result as indication of the presence of the BCR-ABL gene.
2. Quantitative PCR – Measures the amount of BCR-ABL genes in your blood. This is useful to measure your response to treatment, and will give a result in the form of a number. The lower the number the less cancer is detectable.
Frequently asked questions:
• How did I get CML ?
There is no known cause for CML. Some studies indicate that exposure to high levels of radiation may lead to CML and other cancers.
• Can it be passed to my spouse and children?
No. CML cannot be passed from one individual to another. CML is not hereditary and is not passed from one generation to another.
• What is my life expectancy?
With the advances in CML treatment patients who respond well and remain compliant can expect to age as those who do not have CML.
• Can a CML patient have children?
While it is possible to become pregnant on a TKI, woman are advised notto become pregnant until their condition is stable and well managed, often for a few years It is not recommended to use a TKI’s (Glivec, Tasigna, Sprycel etc.) while pregnant as this could affect the baby. It is advised that female CML patients use reliable and effective birth control and discuss the possibility of a pregnancy with your doctor.
Female patients on a TKI should not breast feed as the medication is transferred from the mother to the baby through the milk. This could harm the baby.
Male CML patients are also advised to seek counsel with his physician before starting with a family.
• Do I need to follow a specific diet?
There is no need for specific diet changes however a healthy balanced diet is always advised. The only foods that should be avoided while on a TKI is grapefruit, starfruit and Seville oranges ( including juices or other products made from them e.g. marmalade). The reson for this is theat they may interfere with the amount of TKI in the blood, leading to levels that may be either too high or too low.
Should you experience a specific side effect or an increase in side effects following the consumption of certain foods it is advisable to monitor the cause-effect and if this persist to perhaps remove the food group from your diet.
• Can I use other medication?
It is possible to be treated for CML and other conditions simultaneously. ALWAYS inform all healthcare workers of your condition and if possible present them with the package insert (found in the box of your medication) to help the treating physician in prescribing the correct medication.
Inform your physician immediately of any side effects as this might be due to drug interaction.
ALWAYS consult with your physician before taking herbal or “natural” supplements as these might influence the efficacy of you medication.