Acute Myeloid Leukemia
Acute myeloid leukemia (AML) is one of four basic types of leukemia. It is relatively rare and tends to affect older adults usually people over 60 years of age. The basis of this disease lies in immature hematopoietic cells, AML arises from immature form of cells that gives rise to some types of white blood cells.
Why does a certain specific hematopoietic cell change into a cancer? It is not always known but usually it is a consequence of a chromosomal disorder or a genetic mutation. The reason for such mutation emergence may differ, but in case of acute myeloid leukemia we suspect some outer factors such as certain chemicals (cytotoxic agents used in chemotherapy of other tumors, some components of unleaded gasoline etc.) and exposure to radiation. There are also certainly some genetic conditions that make human body more sensitive to leukemia formation. As an example we observe higher rate of AML in people with Down syndrome.
The symptoms correspond to general characteristics of leukemic diseases. Tumor cells settle in bone marrow, lymph nodes and organs of the body. There are two main problems. Leukemic immature white blood cells can not fulfill their function of immune defense. And what is worse their overproduction suppresses formation of other blood cells (normal white blood cells, red blood cells) and blood platelets.
Symptoms are initially nonspecific (fatigue, fever, night sweats, joint pain etc.). Later enlargement of some organs and tissues appear because of tumor cell infestation (by AML there is slightly enlarged spleen, enlarged liver and swollen gums). The fall in red blood cell numbers becomes obvious and manifests as anemia and anemic syndrome. The lack of function of white blood cells causes repeated infections as a mark of immunodeficiency. Insufficient numbers of blood platelets causes increased bleeding and bruising.
Acute myeloid leukemia progresses relatively quickly and without proper treatment it kills a patient in a time period of few weeks to months.
Symptoms may be very subtle and the disease may be found accidentally from a blood test where we usually find higher white blood cell count and lower red blood cell and platelet numbers. Hematologists usually try to get a sample of hematopoietic cells from bone marrow (usually by sternal puncture) or obtain directly a piece of bone marrow by trephine biopsy (usually with a special thick needle from the iliac crest). These samples are then thoroughly investigated, including the use of methods of cytogenetics and molecular genetics. It allows determining prognosis and starting the correct treatment.
Chemotherapy is the treatment of first choice. There are many treatment protocols which are usually divided into three phases. First phase should kill the majority of leukemic cells by a strong chemotherapeutical agent combined with radiotherapy. It is followed by stabilization phase and long-term maintenance phase during which the residue of the disease should be destroyed.
A bone marrow transplant is another option. It is a risky procedure that, simply told, kills all cancer and healthy blood cells with destruction of the whole bone marrow by very powerful chemotherapy and radiation. After that the patient gets new bone marrow cells from a donor. These cells should spread throughout the body a repopulate and inhabit the bone marrow destroyed by previous treatment. If new cells are not capable of this or when an infection occurs at this stage it is a very serious and often fatal situation.
In case when the patient is in incurable state, we provide at least symptomatic therapy. That means we don’t try to cure leukemia but only treat its symptoms. Lack of red blood cells can be temporarily solved by blood transfusions, frequently occurring bacterial infections antibiotics are treated by antibiotics. Insufficient number of platelets resulting in hemorrhage can also be solved by administering special platelets transfusions.