What is leukemia?
Leukemia is a cancer of the blood and blood-forming cells, such as white blood cells.
Leukemia is a cancer of the white blood cells of the bone marrow. Patients with leukemia have an over-production of a particular blood cell type in the body, the white blood cells (cells that fight infection and provide immunity). The excessive number of white blood cells cause many of the symptoms of leukemia.
Based on the origin, the white blood cells can be divided into two broad types – myeloid or lymphoid:
- Myeloid leukemia (myelogenous leukemia) arises from the uncontrolled production of the blood cells called myeloblasts in the bone marrow. Normally, myeloblasts would turn into white blood cells (other than lymphocytes).
- Lymphoid leukemia (lymphoid or lymphoblastic leukemia) arises from cells called lymphoblasts in the bone marrow. Normally, lymphoblasts would turn into a particular type of white blood cells, the lymphocytes.
Based on how fast it progresses, it is divided into acute and chronic leukemia.
- Acute leukemia: Most of the abnormal blood cells are immature and do not function normally. It progresses very quickly.
- Chronic leukemia: There are some immature cells, but others are normal and function normally. It is slowly progressive.
What are the causes of leukemia?
There are several causes of leukemia. All the causative agents ultimately lead to the damage or alteration of DNA. The probable causes are:
- Genetics: Family history, chromosomal abnormalities, etc.
- Environmental factors: radiation exposure, drugs, and chemicals
- Other underlying blood disorders
How does leukemia kill?
The outcome of leukemia depends on the type of leukemia, the extent of the disease, age of the patient, and the general condition of the patient.
Patients with leukemia may ultimately die due to multiple infections (bacteria, fungal, and/or viral), severe nutritional deficiencies, and failure of multiple organ systems. The patients can also face complications due to the leukemia treatment itself, which can sometimes be life-threatening.
Some patients can go into complete remission.
What are the signs and symptoms of leukemia?
18 Signs and symptoms of leukemia include:
- Frequent infection
- Pale skin and nails
- Nausea and vomiting
- Body pain
- Bleeding gums
- Prolonged bleeding following injuries
- Heavy and prolonged bleeding during menstruation
- Easy bruising
- Swollen lymph nodes around the neck, underarm, stomach, or groin
- Difficulty in breathing
- Weight loss
- Loss of appetite
- Inflammation of the eyes
What are the types of leukemia?
Acute lymphocytic leukemia (ALL)
- Progresses rapidly and spreads to other organ systems through the blood.
- It mostly occurs in children and those older than 45 years.
Acute myeloid leukemia (AML)
- It is the second most common leukemia in adults. Commonly seen in adults older than 55-60 years.
- In AML, the myeloid cells mutate, forming defective cells and prevent the formation of normal, healthy cells.
- There is a decrease in healthy and functioning mature white blood cells, red blood cells, and platelets.
- It is rapidly progressive.
- Slow-growing cancer that begins in lymphocyte cells present in the bone marrow.
- There is an abnormally high multiplication of lymphocyte cells that are immature and do not function properly. This decreases the body’s immunity against infections.
- Spreads to the lymph nodes and other organ systems through the blood.
Chronic myeloid leukemia (CML)
- CML is associated with a chromosomal abnormality known as the Philadelphia chromosome (Ph chromosome).
- Spreads through the blood to other organ systems
Hairy cell leukemia (HCL)
- A rare subtype of chronic lymphocytic leukemia (CLL) that progresses slowly.
- The bone marrow produces a high number of B-cells, a type of white blood cell that normally fights against infection.
- There is a decrease in the production of healthy white blood cells, red blood cells, and platelets.
Myelodysplastic syndromes (MDS)
- A group of closely-related diseases in which the bone marrow produces very few healthy, functioning red blood cells, white blood cells or platelets, or any combination of these three.
How is leukemia treated?
- Chemotherapy: a single drug or combination of drugs that kill cancer cells.
- Radiation therapy: radiation is used to damage the rapidly produced cancer cells, killing them, and inhibiting their growth. It can be applied selectively to a specific area or the whole body.
- Bone marrow transplant: diseased bone marrow is replaced with healthy bone marrow from the patient (called autologous transplantation) or from a donor (called allogeneic transplantation).
- Immune therapy: the body’s immune system is modulated to recognize and attack cancer cells.
- Treatment of symptoms and other diseases: pain, anemia, and infections
- Nutrition: Nutritional supplementation
- Palliative care: for untreatable situations (interdisciplinary medical care to improve quality of life, and reduce pain and suffering in patients with a terminal illness)
- Psychological support
- Treatment of side effects and complications: such as nausea, vomiting, hair loss, and inflammation of the skin