Each member of our clinical medical assistant class was required to choose a cancer and discuss it in a presentation. I chose leukemia, and here is what I found.
Leukemia Defined
Leukemia is a
cancer of the bone marrow, blood, and the lymphatic system in general (a
drainage system that removes excess fluid from the space between the body’s
tissues).
There are
four major forms of leukemia, named for the type of cell affected (myeloid or
lymphoid cell), and for the speed at which it develops (1).
1. acute
myeloid leukemia (AML)*
2. acute
lymphoblastic leukemia
3. chronic
myeloid leukemia
4. chronic
lymphocytic leukemia
Founders
Dr. John
Hughes Bennett is credited as first diagnosing leukemia as a blood disease in
1845, although Alfred Velpeau (1827) and Alfred Donne (1844) described the
disease before him. Bennett called the disease leucocythaemia.
Description
Leukemia occurs
when the DNA inside normal blood cells mutates, causing the cells to develop
and divide more quickly, and to live longer, than normal blood cells. The
resulting overabundance of these abnormal cells, however, cannot fight
infection as normal white blood cells do. In addition, because so many of these
abnormal cells are produced, the bone marrow cannot produce healthy blood cells
as efficiently (1).
Symptoms
*Since the
bone marrow produces ineffective white blood cells, the body cannot adequately
fight disease, leading to increased frequency of fever and infection.
*Because of
the bone marrow’s inability to produce red blood cells, responsible for
carrying oxygen throughout the body, a person with leukemia can develop anemia
(low red blood cell count) and fatigue.
*Because the
bone marrow cannot produce adequate platelets to clot the blood, people with
leukemia may experience frequent and prolonged bleeding (2).
Additional
symptoms include paleness, weight loss; lack of appetite; enlarged lymph nodes,
spleen, or liver; petechiae (small red spots appear on the skin); bone pain; and
excessive sweating.
Risk Factors
Although
most people with these risk factors do not develop leukemia, the following risk
factors can be generally ascribed to one or more leukemia type: prior cancer treatment
with chemotherapy (AML) or radiation (AML, ALL, CML); specific genetic
disorders, including Down Syndrome (AML); exposure to benzene (found in
gasoline and cigarette smoke) (AML); blood disorders; history of leukemia in
the family
Diagnosis
and Mortality
According to
the American Cancer Society, it was estimated that 44,600 people would be
diagnosed with leukemia in 2011, and that 21,780 people would die. Like many
other cancers, men were more likely to die from leukemia compared to women; and for 2011, more people
were estimated to die from leukemia in California than in any other state (over
ten percent of the total). Deaths from leukemia, however, have fallen since at least 2003
(3).*
Treatment
*The most
common treatment for leukemia is chemotherapy, which uses chemicals (via pill
or injection) in the form of imatinib, nilotinib, and dasatinib, to kill
leukemia cells in CML (and some ALL) patients. Imatinib, for example, stops the
functioning of a protein in chronic myeloid leukemia cells.
*Biological
therapy is used to help your body identify and destroy leukemia cells, while
radiation therapy (via x-rays and other forms) is intended to damage leukemia
cells to stop their growth.
*Stem cell
treatment can replace diseased bone marrow with healthy bone marrow. Before
this procedure, the body’s existing bone marrow is destroyed with chemotherapy
or radiation therapy. The bone marrow is then injected with blood-producing
stem cells (1, 3).
*According to a study presented by the American Association for Cancer Research,
blacks and Hispanics were also more likely to die from acute leukemia compared to
whites (17 percent and 12 percent higher, respectively). At face value, the raw numbers seemed to indicate otherwise:
Out of the 2,299 black patients involved in the study, 1,953 died inside a five-year period (about 85%).
Of the 4,428 Hispanic patients involved, 3,322 died in that period (about 75%)
Of the 22,035 white patients in the study, 18,980 died (about 86%).
It is possible that fewer whites than blacks and Hispanics died in the second half of the ten-year study, which would explain the apparent contradiction. The lead physician, Dr. Manali I Patel, explained the findings, saying, "like all disparities in cancer there could be any combination of influences; however we believe that socioeconomic factors and access to care may be playing an important role." (4, 5) It is interesting to note the prediction that more men would be diagnosed with new cases of cancer-- including lekemia-- and more men would die of cancer, compared to women (4).
1. “Leukemia.” The
Mayo Clinic. The Mayo Foundation for Medical Education and Research.
Scottsdale, AZ: 2011. Web. 29 December 2011.
2. “Childhood
Cancer: Leukemia.” KidsHealth. The
Nemours Foundation. Wilmington, DE: 2011. Web. 29 December 2011.
3. “Leukemia.”
The Leukemia and Lymphoma Society. White Plains, NY: 18 March 2011. Web. 29
December 2011.
4. “Cancer
Facts and Figures 2011.” American Cancer Society. Atlanta, GA: 2011. Web. 30
December 2011; “Death Rate Higher in Minorities with Acute Leukemia.” American
Association for Cancer Research. Philadelphia, PA: 19 September 2011. Web. 30
December 2011.
5. "Death Rate Higher in Minorities with Acute Leukemia." AAAS, The Science Society. 19 September 2011. Web. 15 January 2012.
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