Introduction

Leukaemia broadly refers to the cancer of blood cells. Leukaemia is broadly divided into four types based on the rate of progression (acute and chronic), and the type of cell involved (myeloid and lymphoid) 

Acute lymphoblastic leukaemia involves the lymphoid cells a, and is the most common cancer in children under the age of 15.¹ It is one of the four types of leukaemia, with the other types listed below:

• Acute myeloid leukaemia
• Chronic lymphocytic leukaemia
• Chronic myeloid leukaemia  

This article will outline what causes acute lymphoblastic leukaemia, as well as its symptoms, tests, treatment and survival rates.

What causes acute lymphoblastic leukaemia?

Acute lymphoblastic leukaemia occurs when a large number  of white blood cells called lymphoblasts are produced uncontrollably in the body. Lymphoblasts are an immature version of lymphocytes, a type of cell that normally fights viruses.

As the body prioritises producing excess lymphoblasts, other cells are not made in normal quantities. This means patients have fewer  immune cells which normally fight infection, fewer  red blood cells which carry oxygen, and fewer  platelets which help stop bleeding after an injury.² These reduced numbers of cells cause the majority of the symptoms of acute lymphoblastic leukaemia, for example, tiredness and easy bruising. 

Who gets acute lymphoblastic leukaemia?

Some established risk factors for acute lymphoblastic leukaemia include: ^2,3 

• Age under 5 or over 45 
• Exposure to radiation, for example in radiotherapy or scanning machines
• Previous chemotherapy
• Genetic Syndromes 
• History of Smoking 
• Infections throughout childhood
• Very high or very low birth weight
• Male gender

Specifically under genetics, it should be noted that patients with Down’s Syndrome or Klinefelter syndrome are at a higher risk of acute lymphoblastic leukaemia than the average person.⁴ This is because these patients have an extra copy of the chromosome that contains genes linked to causing acute lymphoblastic leukaemia. 

Some viruses that have been linked with the development of acute lymphoblastic leukaemia are epstein-barr virus, which causes glandular fever, and human T-lymphotropic virus.⁴ 

How common is acute lymphoblastic leukaemia?

Worldwide, roughly 3 in 100,000 people will be diagnosed with acute lymphoblastic leukaemia.² 75% of those who are diagnosed will be under the age of 6.²

Though it is rare, the incidence of acute lymphoblastic leukaemia has been documented to be increasing since 1975.¹ Thankfully, there have also been dramatic improvements in treatment and survival rates for patients with acute lymphoblastic leukaemia since then. 

Signs and symptoms of acute lymphoblastic leukaemia

Some signs and symptoms of acute lymphoblastic leukaemia include:^2,4 

• Fever
• Tiredness
• Bleeding and  bruising more easily than normal
• Swollen glands/lymph nodes which are normally painless
• Shortness of breath
• Looking more pale than usual
• Dizziness
• Heart palpitations
• Weight loss
• Painful bones
• Tummy pain
• Lumps felt in the tummy due to enlarged organs 

Fever, tiredness and easy bleeding are the most common early symptoms for acute lymphoblastic leukaemia. Symptoms tend to be fairly non-specific, and feeling ‘generally unwell’ is sometimes the only complaint of patients who are diagnosed.

It should be noted that easy bleeding may present in a number of different ways. Patients may have nose-bleeds or bleeding in the gums. In women, menstrual periods may suddenly be heavier or can last longer  Bruising, which occurs due to bleeding under the skin, also may be a sign of leukaemia if it occurs more frequently than normal.⁴ 

If you or a person in your family  are experiencing any of these symptoms, go straight to your GP. They will then refer you to be seen at the hospital within 24 hours for further investigations.

Diagnosis  

A fast, accurate diagnosis is important if it is suspected that a patient may have acute lymphoblastic leukaemia. The sooner the diagnosis , the sooner a patient can start treatment and prevent the leukaemia from progressing.

blood test is the main test used to diagnose acute lymphoblastic leukaemia.² As it is a cancer of the blood, most patients will have abnormalities in their blood results, for example, a very low number of red blood cells, platelets, or specific immune cells. The blood will also be looked at under a microscope, in which abnormal lymphoblasts may be seen.

It should be noted that abnormal results on blood tests are not always due to leukaemia. Some of the other causes that doctors may have to rule out in patients with abnormalities in their blood test results may include the following:⁴

• Vitamin deficiencies, for example in vitamin B12 or folate
• Viral infections such as glandular fever, HIV or cytomegalovirus
• Autoimmune conditions such as lupus 
• Drug induced 

To confirm a diagnosis, other investigations for acute lymphoblastic leukaemia may be done on top of blood tests. These may include: ² 

• Taking a sample from the bone marrow, to examine under a microscope
• Genetic testing
• Further scans based on symptoms, to rule out any complications

Treatment options for acute lymphoblastic leukaemia

Patients who are diagnosed with acute lymphoblastic leukaemia will be managed under a large team of healthcare professionals. This will include a haematologist (a doctor who specialises in blood disorders), an oncologist (a cancer doctor), a cancer nurse, paediatricians if the patient is under 18, psychological support and a number of others. Together, they will have a meeting to discuss and determine a treatment plan.⁴

Treatment in acute lymphoblastic leukaemia is often different based on whether or not the patient has a ‘Philadelphia’ chromosome in their cells.⁴ A chromosome is a long chain of DNA that is found in our cells.

 A ‘Philadelphia’ chromosome occurs when two chromosomes, chromosome 9 and chromosome 22, switch ends. This can increase the likelihood of a different leukaemia, acute myeloid leukaemia, and change the way that acute lymphoblastic leukaemia should be treated.⁵ 

Patients who have the Philadelphia chromosome, or are ‘Philadelphia chromosome positive’, tend to have a worse prognosis. The Philadelphia chromosome is more common in adults with acute lymphoblastic leukaemia than children.⁶

Treatment will also differ based on age. Prognosis  tend  to be better in children, and so adults with leukaemia may have treatment that is more intense, as well as being more specific to them individually.⁷ 

Treatment options for acute lymphoblastic leukaemia include:^2,7 

• Chemotherapy
• Targeted therapy
• Immunotherapy
• Stem cell transplants
• Radiotherapy

Chemotherapy is the main treatment for acute lymphoblastic leukaemia. There is a wide range of chemotherapy drugs that may be used during the treatment course. These will be tailored to each patient taking into account their symptoms, side effects, age and how severe the cancer is. 

What are the side effects of treatment for acute lymphoblastic leukaemia?

A lot of patients worry about how they will feel during treatment. Some of the side effects of chemotherapy experienced by patients with acute lymphoblastic leukaemia are the following:⁸ 

• Hair loss
• Nausea and vomiting
• Feeling extremely tired

Different people will often suffer from different side effects. Sometimes, chemotherapy drugs can be swapped for others if they are causing significant symptoms. There are also things your healthcare team can do to lessen the effects of chemotherapy, for example, give anti-sickness medications.⁸

Prognosis in acute lymphoblastic leukaemia

The prognosis can vary depending on the factors such as subtype, age, and genetic alteration found in the cancer cell.

Survival times for persons with acute lymphoblastic leukaemia are increasing due to better modern treatments. When looking at a group of patients between 2004 and 2016, survival rates were estimated to be the following:⁹ 

• 90% of children under 15 survived their leukaemia for at least 5 years after their diagnosis.
• 65% of those aged 15-39 survived their leukaemia for at least 5 years after their diagnosis.
• 20% of those aged above 40 survived their leukaemia for at least 5 years after their diagnosis.

It should be noted that these statistics are only estimates, based on a set time period in one area of the UK. They also do not take into account any other factors such as the health status of the patients before they were diagnosed, their risk factors, or whether they were Philadelphia chromosome positive.⁹

Your oncologist (cancer doctor) will be able to give you or your loved one more detailed information about the prognosis specific to you. They will be able to discuss this with you and your loved ones and answer any questions you may have.

Conclusion Being diagnosed with cancer can feel very frightening. However, with ongoing research and recent advances in treatment therapies, the prognosis looks promising. 

There can be a lot of uncertainty about what might happen next, and you may worry about how your loved ones feel. You may also feel angry, confused, guilty, or numb.⁸

It is important to remember that you are never alone in facing a cancer diagnosis, and there is a massive amount of support available. Macmillan and Cancer Research UK both provide support through information on what to expect, people to speak to, and support groups. They are used to helping people with  cancer and so can often be useful to speak to if you have any questions.

Different coping strategies tend to work for different people, though some suggested strategies to try and manage your emotions are listed below:⁸

• Talking to loved ones
• Talking to a healthcare professional, for example, a Macmillan nurse 
• Joining a support group
• Keeping up with hobbies as long as you feel able to
• Planning things to look forward to