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Leukemia
What is Leukemia?
Leukemia is a cancer that starts in blood-forming tissue
such as the bone marrow, and causes large numbers of blood
cells to be produced and enter the blood stream. According
to the NIH, there are more than 80,000 leukemia or lymphoma
deaths in the United States each year. Signs of acute leukemia
may include: easy bruising or bleeding, paleness or easy fatigue,
and recurrent infections or poor healing of cuts.
More men than women are leukemia victims. Leukemia originates
in a cell in the marrow and is characterized by the uncontrolled
growth of developing marrow cells. There are two major classifications
of leukemia: myelogenous or lymphocytic, which can each be
acute or chronic. The terms myelogenous or lymphocytic denote
the cell type involved.
It is now known that all cancers, including leukemia, begin
as a mutation in the genetic material - the DNA (deoxyribonucleic
acid) - within certain cells. The external or internal causes
of such change probably add up over a lifetime. Leukemia begins
when one or more white blood cells experience DNA loss or
damage. Those errors are copied and passed on to subsequent
generations of cells. The abnormal leukemic cells remain in
an immature blast form that never matures properly. They do
not die off like normal cells, but tend to multiply and accumulate
within the body.
Types of Leukemia
There are two major classifications of leukemia: myelogenous
or lymphocytic (depending on the cell type involved). Each
classification can be acute or chronic. The most common types
of leukemia in adults are acute myelogenous leukemia (AML),
with approximately 10,000 new cases annually, and chronic
lymphocytic leukemia (CLL), with about 8,100 new cases each
year.
New Cases Among an estimated 31,500 new cases of leukemia
in the United States this year, about equal proportions are
acute leukemia and chronic types. Most cases occur in older
adults; more than half of all cases occur after age 60. Leukemia
usually strikes ten times as many adults as children. Leukemia
is the most common cancer among children and acute lymphocytic
leukemia (ALL) accounts for 80 percent of the childhood leukemia
cases.
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Leukemia
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