Leukemia

Leukemia is a type of cancer that results from the blood-forming tissue in the bone marrow and/or lymphatic system. There are several types of leukemia; some commonly occur in children, while others are typically present in adults.

White blood cells are important in mounting an inflammatory response and helping to fight off infection. In cases of leukemia, the bone marrow produces an excess of abnormal white blood cells that aren’t able to perform their usual function.

The treatment for leukemia varies and can be a difficult process – it must account for factors such as the type of leukemia as well as other factors.

Symptoms of leukemia

The presenting symptoms of leukemia are diverse and may differ depending on the type of underlying cancer. Common signs of leukemia include:

• High fever or subjective chills
• Persistent fatigue or weakness
• Continuous and/or severe infections
• Unintentional weight loss
• Swollen lymph nodes
• Liver or spleen enlargement
• Easy bruising or bleeding
• Recurrent nosebleeds
• Petechiae or tiny red spots that appear on the skin
• Excessive sweating, especially during nighttime
• Bone pain or tenderness

When should you consult the doctor?

You should consult a doctor if any of the above signs or symptoms are present and worry you. The symptoms of leukemia are diverse, and some symptoms can be easily overlooked as they may be similar to flu or other illnesses. Leukemia is sometimes incidentally discovered when the patient undergoes blood tests for other conditions or diseases.    

What are the causes?

The exact cause of leukemia remains unknown; nevertheless, it may result from some factors linked to the disease, such as certain infections, chemical substance exposures, or underlying immunodeficiency. Leukemia could also develop from a combination of genetic and environmental factors.

The formation of leukemia

It is believed that leukemia occurs when the DNA of hematopoietic stem cells is mutated. A cell's DNA plays a crucial role in dictating the cell’s various functions. Such mutations will cause these cells to grow and multiply uncontrollably. The dysregulated growth of these mutated cells will eventually infiltrate otherwise healthy tissue in the bone marrow. This ultimately leads to the loss of healthy white blood cells, red blood cells, and platelets, and the onset of symptomatic leukemia.   

Classification of leukemia

Leukemia is classified based on the speed of progression and degree of involvement.

Acute leukemia ensues when the mutated blood cells proliferate as immature/precursor blood cells. This lack of maturity means that they will not function correctly when released into the bloodstream, and they multiply at a rate that will cause the symptoms to rapidly worsen. This type of leukemia requires aggressive and timely treatment.

Chronic leukemia consists of several types. Some produce too many cells, while others produce too few. In chronic leukemia, cells become too mature with growth slowdown, meaning that they can only function properly for a short time span. Some type of chronic leukemia has no early symptoms and may even be undiagnosed for many years.

Leukemia can be further classified by the type of white blood cell that is affected. 

• Lymphocytic leukemia is a type of leukemia that primarily affects the lymphoid cells (a type of white blood cell), which build up in lymphoid or lymphatic tissue. Lymphatic tissue is important in helping the immune system function properly.
• Myelogenous leukemia is a type of leukemia that affects the myeloid cells. Myeloid cells are the precursors to red blood cells, white blood cells (except lymphocytes), and platelets.

Different types of leukemia

• Acute lymphocytic leukemia (ALL) – the most common type of leukemia that often occurs in young children and can sometimes occur in adults.
• Acute myelogenous leukemia (AML) – is another common type of leukemia that occurs in both adults and children.
• Chronic myelogenous leukemia (CML) – a type of leukemia that primarily affects adults. Patients tend to have little or no symptoms for many years before the mutated cells begin to multiply rapidly.
• Other types of leukemia include hairy cell leukemia, myelodysplastic syndromes, and myeloproliferative disorders, among other rare types of leukemia.

Risk factors that could increase the chance of developing leukemia

• Previous history of cancer treatment – a patient who had a history of chemotherapy and/or radiation therapy for another type of cancer typically has an increased chance of developing leukemia in the future.
• Genetic disorders – those with chromosome abnormalities such as Down syndrome have a higher chance of developing leukemia.
• Chemical substance exposure – being exposed to certain chemicals such as benzenes has been linked to an increased chance of developing leukemia.
• Smoking cigarettes – smoking may increase one’s risk of developing acute myelogenous leukemia.
• Family history of leukemia – if a family member has previously been diagnosed with leukemia, one’s risk of developing leukemia is elevated when compared to the overall population.

It is important to note, however, that most people with these risk factors don’t often get leukemia, and that most people with leukemia may not have any of these risk factors.

Diagnosis

If a patient exhibits signs or symptoms that could be explained by leukemia, the doctor may advise the following diagnostic steps:

• Physical examination – the doctor will check for physical signs of leukemia, such as pale skin resulting from anemia, rash, swollen lymph nodes, an enlarged liver, and an enlarged spleen.
• Blood tests – the doctor can identify and quantify the levels of red blood cells, white blood cells, platelets, and immature cells by analyzing the patient’s blood counts. This could further aid in the diagnosis of leukemia.
• Bone marrow biopsy – the doctor may instruct the patient to undergo a bone marrow biopsy by removing a sample of bone marrow from the hip bone using a thin needle. The sample will then be sent to the lab for inspection of abnormal cells. This kind of test will also help determine specific mutations and suitable treatment options.

Treatment Methods

The treatment for leukemia depends on the patient’s age, overall health condition, type of leukemia, goals of care, and degree of spread to other parts of the body, such as the central nervous system.

• Chemotherapy – this is an effective treatment option for leukemia that aims to destroy leukemia cells. Sometimes you may receive a single drug or a combination of drugs depending on the type of leukemia. It may be administered as an injection/infusion to the vein or as an oral pill.
• Targeted therapy – this type of treatment focuses on the abnormalities/mutations found within the cancer cells. Targeted drug treatments aim to block the abnormalities in the cell, and result in cancer cells being selectively destroyed.
• Radiation therapy – this type of treatment uses X-rays to destroy leukemia cells and prevent them from growing further. The patient may receive radiation in one specific area of the body or throughout the entire body. It is also used as a method of treatment prior to performing a bone marrow transplant.
• Bone marrow transplant – also known as a stem cell transplant, this treatment aims to reconstruct the healthy stem cell population by replacing unhealthy bone marrow with healthy stem cells. This will in turn help rebuild healthy bone marrow tissue over the long-term. Prior to receiving a bone marrow transplant, the patient will likely require a high dose of chemotherapy or radiation therapy in order to destroy the leukemia cells in the bone marrow and reduce the cancer burden. Next, the patient will receive a blood-forming stem cell that will help regenerate the bone marrow. Sometimes, the patient will also receive stem cells from a donor and can occasionally continue to use their stem cells during the treatment course.
• Immunotherapy – this treatment option stimulates the patient's immune system to fight the cancer. It does so by interfering with the cancer cell’s ability to produce specific proteins that would otherwise suppress the immune system’s defense against the cancer.
• Preparing immune cells to fight leukemia – also called chimeric antigen receptor (CAR)-T cell therapy, this is a relatively novel and specialized treatment option. It works by extracting and changing the function of the patient’s germ-fighting T cells, such that they develop the ability to fight cancer cells. The T cells are then re-introduced into the patient’s body to reduce the cancer burden.

Coping and support

The diagnosis of leukemia can be exhausting for the patient and their loved ones. After a while, you will find a way to cope with the situation and the uncertainty of the disease. Below is a list of guiding factors that may aid in the coping process:

• Research about leukemia so you know how to best understand and address the disease – ask the doctor about the condition, treatment options, and prognosis. The more you know about it, the more confident you will be with making appropriate treatment decisions.
• Maintain a close relationship with your friends and family – strong relationships will help you manage the disease while getting the support you need.
• Talk to someone – find someone to talk to about your hopes and what you are hopeful or afraid of. It can be friends, family, or a cancer support group.
• Take care of yourself – It is always essential to take good care of yourself, whether leukemia-related or not. Try to make time for your favorite hobbies, such as yoga or cooking.

Preparing for the doctor's appointment
Consult your doctor if you have any symptoms that may raise concern. If the doctor suspects you may have leukemia, the doctor may refer you to a hematologist or specialist. The following sections contain some pointers for how you can best prepare for the doctor's appointment and what you can expect from the doctor.

How to prepare for the appointment

• Be fully aware of any restrictions before the appointment and ask for things that you may need to prepare before the appointment, such as a log of your diet or lifestyle factors.
• Note down all symptoms, including any symptoms that may seem unrelated to leukemia.
• Note down personal information, including any recent stressors or life changes.
• Write down all medications, vitamins, or supplements that you are currently taking.
• Come to the appointment with a family member or friend to help you remember information from the doctor.

Questions to ask the doctor

• Are my symptoms occurring because I have leukemia?
• What type of leukemia is it?
• Am I required to undergo any more tests?
• Does it require immediate treatment?
• What are the treatment options?
• Are there any treatments that could possibly cure my leukemia?
• Are there any possible side effects of the treatment?
• Is there any one treatment you feel is most suitable for me?
• How will therapy for leukemia affect my daily life such as going to work or school?
• How can I best manage this if I have other health conditions?
• What will the treatment cost, and will my insurance cover the cost?

Questions to expect from the doctor

• What symptoms are you having?
• When did the symptoms first begin?
• Are these symptoms occasional or continuous?
• What is the severity of these symptoms?
• Is there anything that improves the symptoms?
• Is there anything that worsens the symptoms?
• Have you ever had abnormal blood test results? If yes, when was that?