What is Leukemia? Types, Diagnosis, Treatment & More
Cancer of the white blood cells (WBCs) is called leukemia. The main function of WBCs is to protect the body from invasion by various pathogens like bacteria, virus, fungi, and other foreign bodies. Therefore, white blood cells are an important part of the immune system. In leukemia, these WBCs do not function normally, making the body susceptible to infections.
Different types of Leukemia
The various types of leukemia are mentioned below:
- Acute lymphocytic leukemia (ALL): Acute lymphocytic leukemia is also called acute lymphoblastic leukemia. It is a type of cancer of the blood and bone marrow, affecting specific type of white blood cells called lymphocytes. It takes place due to errors in the DNA of bone marrow cells. This is the most common form of leukemia seen in children but also seen in adolescents and adults.
- Acute myelogenous leukemia (AML): This is a type of cancer of the blood and bone marrow, having excess immature white blood cells. AML shows rapid progression, with myeloid cells interfering with the formation of normal red blood cells, white blood cells, and platelets. This is the most common type of leukemia seen in adults. It can also occur in children.
- Chronic lymphocytic leukemia (CLL): Chronic lymphocytic leukemia develops from a type of white blood cells called B-Lymphocytes. It starts in the bone marrow but later goes into the blood, lymph nodes, liver and spleen. This is the most common chronic form of leukemia seen in adults who have crossed the age of 65 years. It goes undetected as the symptoms remain unnoticed for several years.
- Chronic myelogenous leukemia (CML): This type of blood cancer progresses slowly and affects the bone marrow, liver and spleen. It is caused by a chromosome mutation that occurs spontaneously. Commonly seen in adults. This type of chronic leukemia shows minimal symptoms for several months to years, before entering a stage where the leukemia cells start dividing rapidly.
What Causes Leukemia?
Researchers haven’t yet arrived at a conclusion regarding what causes leukemia. However, there are some risk factors that may increase your chances of developing the same. Some of these have been mentioned below:
- Earlier exposure to chemotherapy or radiation for some other form of cancer
- Other blood cancer diseases
- Genetic disorders such as Down syndrome
- Repeated exposure to cigarette smoke which contains chemical benzene
Symptoms of Leukemia
The symptoms may vary according to the type of leukemia that a person has. Some common symptoms are mentioned below:
- Fever with chills
- Swollen lymph nodes
- Frequent nosebleed
- Excessive sweating, especially during the night
- Enlarged liver or spleen
- Unexplained weight loss
- Fatigue and weakness
- Tiny, red spots on the skin (petechiae)
Diagnosis of Leukemia
Various steps are involved for diagnosing leukemia in an individual.
- Physical examination: The doctor may check for enlarged spleen and liver for the presence of swollen lymph nodes. The physical exam will include checking the skin for rashes which may appear red, brown, or purple in color.
- Complete blood count (CBC): A complete blood picture will show the count of RBCs, WBCs and platelets in the blood. If you have leukemia, your white blood cell count would be relatively high and RBC, platelets will be low.
- Bone marrow biopsy: A bone marrow aspiration test is done if you have an abnormal white blood cell count. In this, a long needle is inserted into your pelvic bone to draw fluid from the bone marrow. The fluid is then tested in a lab to check for leukemia cells. It acts as a confirmatory diagnosis for leukemia by indicating the percentage of abnormal cells in your bone marrow.
- Blood cell examination: Blood cells when observed under flow cytometry will show if markers are present that indicate the presence of leukemia. A peripheral blood smear may additionally be used to confirm the presence of leukemia cells.
- Lumbar puncture: In this, a sample of your spinal fluid is tested to see if leukemia has spread to the spinal fluid surrounding the brain and spinal cord.
- Imaging tests: A chest X-ray, CT scan or MRI (Magnetic Resonance Imaging) may be done to see if leukemia has internally affected your body at the tissue, bone or organ level.
- Flow Cytometry and Molecular Analysis: To sub classify type of blood cancer and determine prognosis.
Treatment of Leukemia
While treating leukemia, a number of factors like age, type of leukemia and overall health, need to be considered. The treatment modality includes a combination of each of these:
- Chemotherapy: It is the most common form of leukemia treatment. Chemicals are used to treat leukemia cells and prevent them from multiplying. A combination of chemotherapy drugs includes medication in the form of pills and an injection.
- Immunotherapy: Certain drugs are given to boost your immune system and help identify cancer cells, to fight them.
- Hematopoetic cell transplant: This treatment replaces the cancerous cells killed by chemotherapy and radiation with new, hematopoetic cells. The healthy cells may be drawn from your blood before chemotherapy or radiation therapy takes place or it may be obtained from a donor.
- Chimeric antigen receptor (CAR) T-cell therapy: It takes the T-lymphocytes of the immune system, programs them to fight against the leukemia cells and then infused back into the body.
Frequently asked questions (FAQs)
How do I know if I am susceptible to leukemia?
You are at a risk of developing leukemia if you have been exposed previously to radiations or chemotherapy for the treatment of other types of cancer. Other factors include a genetic predisposition and exposure to hazardous chemicals and smoke.
What is the difference between acute and chronic leukemia?
- Acute leukemia: These are immature cancer cells called blasts which rapidly grow. The disease generally worsens unless treated.
- Chronic leukemia: It is characterized by both young and mature, functional cells. These cells are slow to grow and the disease doesn’t worsen with time. It takes several months to years to detect it as the condition remains stable for long, even without treatment.
Should one get a second opinion for leukemia?
Getting a second opinion for leukemia is always advisable as the person may not be comfortable with the treatment decision. Leukemia is a relatively rare form of cancer and people may want to explore other ways to treat it.
Can leukemia be prevented?
Although there is no way to prevent the onset of leukemia, certain changes in lifestyle can go a long way to prevent it. Smoking should not be encouraged as it is associated with the risk of developing acute myeloid leukemia (AML). Quitting this habit can also keep cancer of neck, lung, and other forms of cancer at bay.
Dr M. P. Ram Prabu
Senior Consultant - Medical Oncology
Gleneagles Global Cancer Centre