“Far from the death sentence it once was, Chronic Myeloid Leukaemia (CML) - a particularly aggressive form of blood cancer - is now a curable disease. Exciting new therapies offer patients a range of treatments, enabling many with the condition to live long, healthy lives,” says Professor Vernon Louw, Head of the Clinical Haematology Unit in the Department of Internal Medicine at the University of the Free State.
“When our 10 year old daughter was first diagnosed with CML, it felt like we were trapped in a dark abyss,” says Anne Thomson, mother of Emma. “The news that our daughter had leukaemia was absolutely devastating and we couldn’t see a way out.”
Five and a half years later, Emma is a healthy 16-year old who, after undergoing chemotherapy and a stem cell transplant, has been cured of CML.
CML represents nearly 15% of all leukaemias, affecting about 2 out of 100 000 people each year across the world1. According to Louw, while the disease occurs in all age groups, the incidence does increase with age so the disease is primarily prevalent in adults. “Most CML patients are diagnosed at around 55-60 years old, with less than 10% of CML cases being diagnosed in patients younger than 20 years,” he says.
Excessive production of white blood cells
“In CML, a genetic abnormality known as the Philadelphia chromosome affects the functioning of the bone marrow – the factory that makes blood,” says Louw. “This leads to the excessive production of white blood cells, which later accumulate in the patient’s liver and spleen.”
CML usually progresses through three phases – a chronic, accelerated and blast phase. Without treatment, patients diagnosed with first stage CML generally survive between 5-7 years2. The chronic phase of the disease usually extends for 4-5 years before it progresses to the accelerated phase which lasts about 3-18 months. Once a patient progresses to the blast phase, survival is estimated at between 3-6 months 3.
“Early diagnosis is critical,” says Louw. “If a patient experiences symptoms such as fatigue, weight loss, fever, persistent, unexplained bone and joint pain or abdominal fullness1,, they should go to the doctor for a check up as soon as possible.”
Shaun Watts, who was diagnosed with the disease when he was 3-years old recalls that he felt completely washed out after returning from an overseas trip, but didn’t suspect anything sinister. “I went for a check-up and thought I would come back with a prescription for vitamins,” he says. “I was shocked when I was told that my blood tests showed that I had CML.”
Better chances of recovery
Luckily Watts was diagnosed at an early stage of the disease which meant his chances of recovery were better. Fourteen years later, Watts still takes a daily dose of drugs to keep CML cells under control. He remains in remission, meaning that the number of cancerous cells in his body is so low that they can no longer be detected in the blood or bone marrow via standard tests.
“After thinking that I may not get to watch my boys grow up and complete school, I’m about to celebrate my 50th birthday,” says Watts. “A diagnosis of CML no longer means you’ve got a few months or years to live - new treatments mean you can dream about the future.”
Until the 1980s, CML was regarded as a fatal disease. Aside from surgery, which almost always leaves behind some malignant cells, the standard treatment for most cancers was radiation and chemotherapy. Bone marrow transplants were also used to try to replace the patient’s damaged cells with cells from a healthy donor.
Nowadays however, targeted molecular drugs and stem cell transplants offer patients new hope. Stem cell transplants have proven to be a cure for some, but not all CML patients.
Goal of treatment
“The goal of CML treatment is to control the signs and symptoms of the disease; suppress, eliminate and reduce the number of cells containing the Philadelphia chromosome and prevent the progression of CML into its advanced phases 4,” says Louw.
Recent developments in treatments for CML have provided physicians and patients with more complicated treatment decisions. Although some patients with CML can be cured with a stem cell transplant, says Louw, the risks associated with the procedure should be carefully assessed.
“Much depends on the age of the patient and how far the leukaemia has progressed,” he says. “Both transplant and non-transplant treatments and risks have improved considerably in recent years, so it’s important to consider all options.”
“The younger a CML patient, the more chance they have of recovering from a stem cell transplant. With increased numbers of donor registrations across the globe, a patient still has just a 60 – 70% chance of finding a suitable donor.”
“In chronic phase CML, transplantation is actually the alternative or second choice therapy while long-term targeted therapies are considered a first line treatment. One of the most exciting new therapeutic approaches to the treatment of CML is the introduction of the signal transduction inhibitors (STIs),” says Louw. “These provide a dramatic and revolutionary example of how understanding the biology of disease can lead to successful molecular-targeted treatments.”
Louw says scientists use computer modelling to design therapies that shut off particular cells. This disrupts their communication patterns and results in cancerous cells self-destructing, rather than bombing them with chemotherapy. “These breakthrough drugs can kill off cancerous cells in a matter of months, compared to the years taken by traditional chemotherapy,” he says.
While chemotherapy destroys all rapidly dividing cells – both good and bad, targeted therapies work by disrupting the functioning of cancerous cells in particular. “The side effects are therefore less severe. In fact one of the challenges is that patients tend to feel so much better on the targeted therapy that they stop taking it every day and this can lead to resistance,” says Louw.
Second and third generation drugs are already being developed that will be more and more precise in attacking cancer cells. “Advances in science have significantly increased the survival rates of CML patients,” says Louw. “Cancer patients will soon have a bigger range of weapons to choose from in the fight against cancer.”
- Early diagnosis is critical: If you are feeling extremely tired, have swollen glands or a distended abdomen, go to your doctor as soon as possible. Spontaneous bruising and recurrent infections can also be a sign of leukaemia. The earlier leukaemia is diagnosed, the better the chance of successful treatment.
- Knowledge is power. Find out as much as possible about the different treatment options so you can make an informed decision. Don’t be afraid to ask your doctor to explain things to you in simple terms.
- Call your medical aid. Check what oncology benefits they cover and work out how you will fund any additional costs.
- Share the burden. Talk to friends and family about your feelings and concerns and request help if you need it.
- Maintain a healthy lifestyle. Eating a balanced diet is important to boost your immune system and improve your chances of recovery. Avoid smoking too.
- Avoid over-the counter drugs. They can interact with anti-cancer medication, rendering it less effective or worsening their side-effects.
1) Druker BJ, Lee SJ. Chronic Leukaemias. In: De Vita VT, Hellman S, Rosenberg SA, eds. Cancer: Principles and Practice of Oncology, 7th ed. Philadelphia, Lippincott Williams & Wilkins: 2004: 2121-2154.
2) Faderl, S, Kantarjian H, Talpaz M, et al. New treatment approaches for chronic myelogenous leukemia. Semin Oncol. 2000; 27:578-586.
3) Faderl S, Talpaz M, Estrov Z, et al. Chronic Myelogenous leukemia: biology and therapy. Ann Intern Med. 1999a; 131:207-219.
4) Chronic Myeloid Leukemia Trialists’ Collaborative Group. Hydroxyurea versus busulfan for chronic myeloid leukemia: an individual patient data meta-analysis for three randomized trails. Br J Hematol. 2000; 110:573-576. (Bespoke Communications/ October 2010)