Bone marrow is a soft, fatty tissue that stores “stem cells”, which on maturing turns into blood cells. Stem cells are specialized cells that have the potential to grow and develop into various other types of cells. Thus, marrow is said to be the body’s blood factory where a single type of multi-protein stem cells divides and matures to give rise to different kinds of blood cells.
Unlike most Cancers, leukemic cells don’t belong to an organ and don’t result in the growth of a tumor. Instead, the uncontrolled cell growth takes place in the bone marrow. The leukemic cells are generally immature and do not carry out any physiological function of use to the body.
The word leukemia is derived from the Greek words “Leukos” meaning white and “aima” meaning blood.
Millions of blood cells are made every day and millions die at the end of their lifespan. There is a fine balance between the number of new blood cells and the number of worn out cells which gets phased out or die. Various factors help to maintain this balance. For example, certain hormones in the bloodstream and chemicals in the bone marrow called ‘growth factors’ help to regulate the number of blood cells. However, the abnormal blood cells do not follow this cycle; they continue to grow uncontrollably crowding out space in the blood, thereby impeding the function and growth of healthy blood cells.
The build up of immature lymphoblasts is called acute lymphoblastic leukemia. In order to confirm if the affected cells are lymphoid cells, TdT is checked. TdT is a DNA polymerase that’s present only in the lymphoblasts. ALL is the most common type of leukemia accounting to almost 80% of all leukemia cases. It primarily occurs in young children between the ages of 1 and 4 but the prognosis is quite good and although it is rare among adults in whom the prognosis is generally poor.
ALL is further subtyped based on B cells or T cells.
Acute Myelogenous Leukemia (AML)
The build up of immature myeloid blasts is calledacute myeloid leukemia. To verify if the affected cells are myeloblasts, the presence of enzyme myeloperoxidase is checked. AML is more common among adult men between the ages of 50 and 60. Chemotherapy is the most preferred treatment option for this Cancer.
Chronic lymphocytic Leukemia (CLL)
Chronic lymphocytic leukemia (CLL) is a type of Cancer that starts fromlymphocytes in the bone marrow. This is most common leukemia among men over 55 years, although younger adults can get it as well. In CLL, the leukemia cells often build up slowly over time, and many people don’t have any symptoms for initial few years. Though rarely able to be cured, most patients with CLL survive without treatment for years. On progression of the disease, they must be treated properly.
Chronic Myelogenous Leukemia (CML)
This Cancer occurs mostly in adults. A drug called imatinib is commonly used to treat CML.
Occurrence Rate :
Leukemia is one of the most deadly diseases which are very hard to treat. Almost 350282 people are diagnosed with leukemia each year around the globe.
A symptom is any abnormality shown by the body due to improper functioning of a single or group of organs. Since there are different types of leukemia so the symptoms of each type also differ.
However, in most cases the symptoms are not clear enough for suspicion of chronic leukemia; it can be confirmed only by a medical examination. So it is highly recommended visiting a doctor in case of experiencing any of the mentioned symptoms.
While the exact cause(s) of leukemia is not known, risk factors have been identified, which increases the chance that certain leukemia may develop. But these risk factors account for only a few cases. Some of the risk factors are:
There is no known way to prevent most types of leukemia. Some types of leukemia may be prevented by avoiding high doses of radiation, exposure to the chemical benzene, smoking and other tobacco use, or certain types of chemotherapy used to treat other types of Cancer.
Staging of Cancer is essential for determining the location and spread of the Cancerous cells. Also, it is based on this stage that the complete prognosis of the patient can be planned. Usually, a numbered staging system is used to describe most types of Cancer/solid tumors and their spread throughout the body.
But for Acute lymphocytic leukemia, staging is done in a bit different way. Since the disease originates within the bone marrow and it is likely spread to other organs before detection, the staging method needs to take into account several other factors.
|Type of Leukemia||5 year survival rate|
Mortality (death) rates for leukemia are higher in the elderly than in younger adults and children. In many cases, leukemia can be cured with treatments available today. The survival rate, however, cannot predict the outcome of any particular patient as the outlook varies largely on the basis of overall health condition, age and several other factors.
Modern treatments have led to a greater than fourfold increase since 1960 in five-year survival rates for leukemia. Five-year survival rates for different types of leukemia are approximately:
As many types of leukemia do not show any early symptoms so it becomes a bit tricky to detect the disease at an early stage. However, being alert and not neglecting any minor signal regarding your health many a times proves to be life saviour. In case of any doubt about the disease, there are several tests that aid to clear the air.
This is the first step of diagnosing leukemia. During the physical examination, the overall health record of the patient is taken into account and any sign of swollen glands is checked. If the person appears pale or complains about any of the mentioned symptoms then the doctor should suspect leukemia.
Since leukemia is the Cancer of blood, a blood test gives a lot of information. Leukemia is suspected if a blood test shows large numbers of abnormal white blood cells and low numbers of normal white blood cells, red blood cells or platelets. If leukemia is detected then blood test is repeated after every three months for at least two years.
A biopsy is done if leukemia is suspected and this test helps to identify the type of leukemia. In this procedure, a small amount of the Cancerous cell from the marrow is removed using a syringe and is observed under a microscope. Bone marrow biopsy may be uncomfortable and so sometimes the use of anesthesia is preferred.
In case of enlarged lymph, a lymph node biopsy is suggested. Tissues from the affected lymph are removed and examined under a microscope.
Several imaging tests like CT scan, X- ray, MRI may be performed to ascertain the spread of leukemia.
The genetic changes that occur in leukemia often involve chromosome changes, which can be seen under a microscope or using laboratory tests.
This is done to check for leukemic cells in the spinal cord and brain. In this procedure, a fine needle is inserted between the bones in the lower back to take out a sample of fluid which are then evaluated under a microscope
The treatment plan for leukemia depends largely on its type, age and health status of the patient. There are a number of different medical approaches to the treatment of leukemia.
Treatments for leukemia include chemotherapy (major treatment modality for leukemia), radiation therapy, biological therapy, targeted therapy, and stem cell transplant. Combinations of these treatments may be used. Surgical removal of the spleen can be a part of treatment if the spleen is enlarged.
Types of supportive and preventive treatments that can be used for patients undergoing treatment for leukemia include the following: