Leukemia is cancer of the body’s blood-forming tissues, including the bone marrow and the lymphatic system. There are two main types of leukemia, chronic and acute, which can be further separated into common types, with the most common being lymphocytic and myeloid. Lymphocytic leukemia begins in the lymphocytes (white blood cells) while myeloid leukemia begins in the myeloid cells, called granulocytes and monocytes. Both lymphocytes and myeloid cells are part of the body's defense against disease.
Acute lymphocytic leukemia (ALL) progresses rapidly, replacing healthy cells that produce functional lymphocytes (white blood cells) with leukemia cells (blasts) that cannot mature properly. The proliferation of these abnormal cells crowds out other types of healthy blood cells in the circulating blood. Leukemia cells can sometimes spread to other organs and tissues where they grow and divide.
Acute myeloid leukemia (AML) is a fast-growing cancer that causes the bone marrow to overproduce abnormal white blood cells, crowding out healthy blood cells and affecting the body’s ability to fight infections.
Chronic lymphocytic leukemia (CLL) is typically slow-growing cancer that begins in lymphocytes within the bone marrow and extends into the blood. CLL is very similar to ALL, however, because it is slow-growing, it can take longer to start causing symptoms.
Chronic myeloid leukemia (CML) begins in the blood forming cells of the bone marrow and then, over time, spreads to the blood and other areas of the body.
Symptoms of all forms of leukemia include fatigue, shortness of breath, fever, easy bruising or bleeding, infection, weight loss, and flu-like symptoms.
Leukemia starts when the DNA of a single cell in the bone marrow mutates. The cell is then unable to mature, or may be malformed. All cells arising from the original mutated cell also have the mutated DNA, and reproduce very rapidly, gradually crowding out normal cells and interfering with their functions, as well as weakening the immune system
Scientists aren’t sure what causes these developing cells to mutate. For some types of leukemia they have been able to identify common mutations that occur, while other types of leukemia appear to have a variety of causes. While people of any age can develop leukemia, the median age of patients diagnosed with AML, CLL, and CML is 65 years and older; however, most cases of ALL occur in people under 20 years old.
The highest rate of ALL is found among Hispanic children and adolescents, more than any other demographic group in the United States, possibly due to a genetic predisposition.
Leukemia is life-threatening, and treatments include chemotherapy, radiation therapy, and blood stem cell/bone marrow transplant.
In a peripheral blood stem cell (PBSC) or bone marrow transplant, the patient’s non-functioning bone marrow is cleared away by chemotherapy and replaced with healthy cells donated by a matching family member or unrelated donor. The transplanted cells migrate into the bone marrow and multiply, forming healthy bone marrow tissue that produces new blood and immune system cells free of the disease.
For the transplant to work, the donor and the patient must have matching immune system factors, called Human Leukocyte Antigens (HLA). People get their HLA types from their parents, one half from each parent. Only about 30% of patients can find a match with another family member; the other 70% of patients must search the registry for an unrelated donor. People with the same ethnicity have the best chance of being HLA matches, due to the way these factors are inherited. Looking at where your ancestors were living generations ago can give doctors a good idea of who might be the perfect match.
Because leukemia can be cured with a PBSC or bone marrow transplant, the best way to help is joining the registry so more donors are available. Anyone 18 to 35 years old and in general good health can join the registry by completing a cheek swab kit at an in-person drive or by ordering a kit online, which can be sent to your home.
You can also organize and host your own donor recruitment events. Gift of Life has over 30 years of experience organizing events, and we stand ready to help you coordinate yours.
In addition, you may also help out by spreading the word. Following Gift of Life on social media and sharing this article and others like it will help share information about what our organization does and why our mission is so important. This can help others join the registry!
• AACR Cancer Disparities Report 2022, pp. 24, 47
Image of leukemia blasts CC BY-SA 3.0 By VashiDonsk at English Wikipedia.