What is Leukemia?
Leukemia is a cancer of the white blood cells. It begins in the bone marrow, where we produce white blood cells, and causes us to have lots of abnormal cells. There are several different forms of leukemia, with a range of symptoms.
What Causes Leukemia?
Leukemia is a form of cancer – typically a collection of damaged cells which grow in an uncontrolled manner and do not follow the natural life and death cycle of cells. Leukemia happens when some of the cells in the bone marrow become damaged and diseased. White blood cells are part of the immune system, circulating in the blood and responding to infection risks in the body. They are made in the bone marrow and released into the blood, so a bone marrow cancer affects the health and number of some of those blood cells. Having too many abnormal cells causes problems in itself, but also means that we can have too few of the healthy, normal cells, causing further problems.
The trigger and underlying cause of leukemia isn’t always obvious, but there are a few risk factors we know can make us more prone to developing leukemia, including exposure to radiation or certain harmful chemicals.
Leukemia vs Lymphoma
Leukemia and lymphoma are often grouped together as they are both cancers of the blood and immune system, and are different from the typical cancers that affect single organs or present as ‘lumps’ or tumours. Although they have similarities, they affect the body in different ways:
- Leukemia is a cancer of the bone marrow which affects the production of cells. Overproduction of blood cells that do not follow a normal lifespan means that there can be very high numbers of abnormal cells within the bone marrow and entering the circulation, eventually taking over space from healthy blood cells of all types.
- Lymphoma is a cancer affecting the lymphatic system – the system of glands, nodes and vessels which forms part of the immune system. Lymphoma is overall slightly more common than leukemia.
Leukemia Survival Rate
The likelihood of surviving leukemia varies greatly from person to person, and depends on a number of factors, including their age at diagnosis, their overall health and any other conditions that affect treatment, which type of leukemia they have and how quickly it is progressing, the underlying cause and treatment taken. Overall, the five year survival rate from leukemia is around 65%.
Types of Leukemia
There are four main types of leukemia, named to describe the speed of onset and the type of blood cell they affect.
1. Acute lymphoblastic leukemia (ALL)
ALL is a type of acute, or fast-growing leukemia that is most likely to affect young children, especially the under-5s. It can also affect older adults, and the prognosis for adults is worse than for children – four out of five deaths from ALL is an adult with the condition, but 90% of adults with ALL have complete remission.
2. Acute myeloid leukemia (AML)
AML is an acute leukemia – this means that it develops rapidly. It tends to affect older adults, although it is also occasionally seen in children and younger adults. AML affects men more commonly than women.
3. Chronic lymphocytic leukemia (CLL)
CLL is a type of leukemia that develops quite slowly, and people with CLL can live for many years with the disease without developing any significant symptoms. The average age of diagnosis is around 70 years.
4. Chronic myeloid leukemia (CML)
CML is a form of leukemia that progresses slowly, and may take many years before it causes enough symptoms to become a problem. The average age at diagnosis is 64, and CML is rarely seen in children.
Leukemia in Adults
There are around 200 new cases of blood cancers every year in Singapore. Leukemia is sometimes thought of as a childhood cancer, but different forms of leukemia affect people of different ages, and overall our risk of developing most forms of leukemia rises as we get older. We sometimes think of leukemia as a disease that particularly affects children, as leukemia is the most common cancer in children. But children rarely get any kind of cancer, and the vast majority of people who develop leukemia are older adults.
Leukemia in Children
Leukemia is the most common form of cancer in children, accounting for around 40% of childhood cancers. Thankfully, cancer in children is not common; there are around 120 new cases of childhood cancer of any kind in Singapore every year. Most leukemias in children are acute, and treatment regimes are improving all the time, with more than three quarters of children with leukemia achieving remission.
Cancer staging is a way of describing the severity of a cancer. With the sort of cancers that form tumour, it is easier to describe the size and spread of the tumour, and whether there are secondary tumours. With leukemia, a cancer of the blood, it is a little harder to describe the extent of the cancer in the way we do with other cancer staging. Doctors look at a combination of factors to work out the stage of leukemia – how severe the leukemia is, the type of leukemia, and to make a treatment plan. Blood tests which show the numbers of healthy cells and leukemia cells are usually the main factor that guides treatment and informs prognosis.
Most of the symptoms of leukemia are caused by a lack of healthy blood cells, especially a lack of red blood cells causing anaemia and related symptoms. Different forms of leukemia vary, and no two people have quite the same experience of cancer, but some symptoms which are common to most leukemias include:
- Appearing pale or ‘washed out’
- Picking up lots of infections, or struggling to get over minor illnesses like colds
- New or severe bleeding gums or frequent nose bleeds
- Bruising easily
- Being very tired – to the point where it affects normal life
- Bone or joint pain.
Some people may also experience generalised pain, unexplained fevers, and weakness. Symptoms which could indicate leukemia can also be related to other conditions, so it’s important to get proper medical advice and diagnosis for any worrying symptoms.
Risk Factors for Leukemia
Leukemia can occur at random, and many people who develop leukemia do not have any discernible excess risk factors. We do know that there are some factors that can make us more likely to develop leukemia, and these include:
- Certain genetic disorders, including Down’s Syndrome.
- Exposure to a chemical called benzene, which is found in some industrial emissions, hazardous waste, petrochemicals, and in tobacco smoke.
- Exposure to high doses of radiation, sometimes given for a previous cancer. Medical radiation is now usually very targeted and used at as low a dose as possible, with careful risk/benefit analysis.
- Family history of leukemia – there seems to be a genetic element to CLL in particular, and having a close blood relative who has or has had CLL makes us more likely to develop the disease, although the risk is still very small.
Some people have higher levels exposure to cancer-causing chemicals or radiation in the workplace, such as those who work in nuclear laboratories or factories producing some kinds of rubber or printing inks. Employers have a duty to provide education and protective equipment to workers at risk of occupational exposure to carcinogens.
Leukemia is usually diagnosed after symptoms begin. It may be considered as one possible cause of a set of troublesome symptoms; a patient may consult a GP with extreme fatigue, breathlessness, and other symptoms, and a series of tests will be done to look for a cause. Blood tests and bone marrow biopsies are the definitive diagnostics for leukemia.
Blood tests taken to help diagnose leukemia are also helpful for showing how well some of the other organs are working, and whether there are other issues like anaemia developing alongside leukemia.
Is Leukemia Curable?
When cancer treatment is successful, we may talk about the cancer being in remission, rather than being cured. This means that there may be some cancer cells remaining, but that they are not causing any problems at that time.
Treatment for leukemia now has a very good success rate, and many people go on to have a full recovery from leukemia. After recovering from leukemia, most people have regular check-ups for a long time afterwards to make sure that the disease stays in remission.
There are a number of different treatments for leukemia, and sometimes a combination of more than one therapy is used. As a cancer of the blood, leukemia does not have a single main tumour or site of most concern so surgery is not usually appropriate – beyond a diagnostic biopsy. Common treatments for leukemia in Singapore include:
The main form of treatment for leukemia is chemotherapy. There are a number of chemotherapy agents licensed for use in leukemia, and the type, duration, and frequency of treatment will be based on individual assessment and advised by a specialist team. Chemotherapy for leukemia aims to control the disease by killing as many of the cancerous cells as possible. Chemotherapy for leukemia typically has some significant side effects, including hair loss, nausea and sickness, diarrhoea, bruising and bleeding, and can have short- and long-term effects on fertility.
Bone marrow (stem cell) transplant
Stem cells from a compatible healthy donor can be used to replace areas of diseased bone marrow in someone with leukemia, seeding and re-growing healthy bone marrow.
Radiation therapy is used to kill cancer cells – it is used in specific situations in leukemia leukemia when cancer is spreading and growing in specific organs, or to prepare for a bone marrow transplant.
Other medications are ‘targeted therapy’, which is used to block cancer growth and ‘biological therapy’, used to boost a person’s own immune system response to the cancer.
Cancer specialists are known as oncologists, and doctors who specialise in blood disorders are known as haematologists. People having treatment for leukemia will be under the care and support of a team of healthcare professionals who specialise in cancer and leukemia. The team may include consultants and junior doctors, specialist nurses, and more.
Cancer treatments are always at the forefront of medical research, and people receiving treatment for leukemia may be offered an opportunity to take part in clinical trials for new treatments.
As the underlying risk factors for leukemia are complicated, it’s not usually possible to predict or prevent leukemia.
The risk factors that we do know that could be avoided include exposure to high doses of radiation or to the chemical benzene. Avoiding smoking may help to prevent leukemia, as well as other serious illnesses.
The best thing we can do to help prevent serious illness, and to give ourselves the best chance of recovery when we do become unwell, is to live as healthy a life as possible. A good diet and regular exercise, stopping smoking and minimising alcohol intake are all important ways to help us stay healthy.
Leukemia Support Group and Resources in Singapore
Any cancer diagnosis can feel overwhelming, but no one has to fight cancer alone. There are many local, international, and online organisations created by and for people with cancer and cancer survivors to support each other through this difficult time.
Some people, especially if they’re feeling unwell, may need support with day-to-day living, and may benefit from home visits from carers, nurses, or doctors who can help them through their cancer diagnosis and treatment. Having help to get to appointments can also make a huge difference.
If you have any concerns about symptoms, or if you’re struggling with a difficult diagnosis, it’s always okay to ask for help.
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