FREE ESSAY ON MULTIPLE CAUSATION THEORY OF LEUKEMIA

MULTIPLE CAUSATION THEORY OF LEUKEMIA

Leukemia is a malignant disease of the bone marrow and blood. It is characterized by the
uncontrolled growth of blood cells. The term leukemia has a Latin derivation. Leuko means
white and heme is blood. Therefore the word leukemia literally means white blood. The
common types of leukemia are divided into four major categories: myelogenous and
lymphocytic, which can then be divided into acute or chronic. Thus, the four major types
of leukemia are acute or chronic myelogenous leukemia and acute or chronic lymphocytic
leukemia. 
Acute leukemia involves the most primitive types of leukemia cells. It is a rapidly
progressing disease that results in the accumulation of immature cells in the marrow and
blood that do not function. In most cases, the marrow can no longer produce enough normal
red and white blood cells and platelets. This class of cancer leads to an overproduction
of blood cells that have similar characteristics, which mean that they are clones. Cloned
cells share two common features that lead to the symptoms of leukemia. The first is that
the cells divide without control and fail to respond to the signals that tell them to
stop. The second is that these cells have a longer life than normal cells and gradually
accumulate in the bone marrow (www.leukemia.org).
This uncontrolled production of long lived cells leads to the replacement of the normal
cells in the bone marrow with leukemic clones. Since the space is limited in the marrow,
the normal cells are crowded out by these clones (www.meds.com). All the normal
blood-forming elements are eventually affected if the leukemia goes unchecked. This means
that the white cells, platelets and red blood cells are all eventually depleted. The
lower number of normal white blood cells makes leukemic patients more vulnerable to
infection. The depletion of normal platelets interferes with the patients clotting
ability and makes the patient more susceptible to abnormal bleeding and bruising. Anemia
is caused by the decreased production of normal red blood cells. Leukemic cells are
actually abnormal white blood cells. As these cells clone themselves they increase the
concentration of white blood cells in the blood stream. Chronic leukemia seems to
progresses more slowly and permits greater numbers of more mature functional cells to be
made.
Now that I have presented the background for the disease itself, it's time to look at it
from the "Multiple Causation Theory." This theory has five basic categories:
biological/genetic, demographic, environmental, psychological, and social interaction.
Before I discuss these categories, I must first present the information that the theory
is concerned with. And that is a) the incidence of new cases and b) the prevalence or
total number of illness within a given population.
It was estimated that there would be 30,200 new cases of leukemia in the United States in
1999. There would be equal proportions are acute leukemia and chronic types
(www.leukemia.org). Most cases occur in older adults; more than half of all cases occur
after the age of 60. Leukemia is expected to strike ten times as many adults as children
in 1999. About 27,900 cases compared with 2,300 in children, ages 0-14. The most common
types of leukemia in adults are acute myelogenous leukemia (AML), with an estimated
10,100 new cases annually; and chronic lymphocytic leukemia (CLL), with some 7,800 new
cases in 1999. The most common form of the leukemia in children is acute lymphocytic
leukemia (ALL). It accounts for about 3,100 new cases of leukemia in 1999, with 1,500 of
these new cases occurring among children. Chronic myelogenous leukemia (CML) strikes
about 4,500 persons each year. Other forms of leukemia strike about 4,700 persons each
year.
The first category that I will talk about is biological/genetic. This category refers to
an inherent bio-physiological state that predisposes certain persons to particular
illnesses as a result of physical inheritance. But as stated in the article, there is no
evidence that any form of cancer can be inherited. Even in the very rare cases of cancer
being present at birth, the disease has developed as a result of cell damage, which
happened in the uterus. In the vast majority of cases of leukemia and other forms of
cancer there is no evidence that relatives of the patient are at greater risk than any
one else (www.cancernews.com). 
There are some inherited conditions in which the risk of developing cancer is increased.
Examples include Down's syndrome and a condition called ataxia telangiectasia. This
condition affects the ability of the cell to repair damage to the genes and because of
this many different cancers are seen more frequently than in the general population. In
other cases, including Down's syndrome the reasons are not well understood
(www.cancernews.com). 
The second category is the demographic of the disease. This refers to social status
characteristics such as age, sex, social class, race, income, and education. The
characteristics of social class, income, and education don't really come into play with
the different leukemia types because everyone is susceptible. Age plays a big part in
which type of leukemia a person will develop. There are a few types of cancer, which
occur more commonly in childhood than in adults. One of these is acute lymphoblastic
leukemia, which is more common between the ages of 2 and 5 years than at any other age.
This is known as the childhood peak of leukemia. Some diseases, such as myeloma and
chronic lymphocytic leukemia, are almost never seen in young people
(www.leukamia.demon.co.uk). The leukemia death rate for children in the U.S. has declined
57 percent over the last three decades. Nonetheless, in children under age 15, leukemia
causes more deaths in the U.S. than any other disease. There were approximately 550
deaths from childhood leukemia in 1999 (www.cancernews.com). 
The risk of developing leukemia increases with age. The increased numbers of cases of
many types of cancer in older people is probably simply a result of the accumulation of
genetic damage to cells over the years. Much of the time damage to the cell will result
in cell death but with over 3 million new blood cells being produced every second it is
inevitable that some cells will accumulate damage to genes over the years. Over the last
20 years, death rates for leukemia have fallen 21 percent for U.S. men and women under
the age of 65.
In total, 22,100 persons died from leukemia in 1999 in the U.S., approximately 12,400
males and 9,700 females. Incidence rates for all types of leukemia are higher among males
than among females and higher among whites than African Americans. The five-year survival
rate for African American patients with leukemia is 31 percent (www.meds.com). These
statistics that have been presented show that it is possible for anyone to develop this
form of cancer.
The third category is environmental. In this category, we look at what people may have
been exposed to in their home and occupational environments. The cause of leukemia is not
known. But scientists have formed many ideas. The most common chemical exposure linked to
leukemia is probably cigarette smoking, which has been shown to be a significant risk
factor for acute myeloid leukemia. It has been estimated that as many as a quarter of all
cases may be caused by smoking (www.leukemia.org). Another cause of leukemia could come
from benzene. Benzene in high concentrations is known to cause leukemia and it is
possible that other, similar organic chemicals, may increase the risk of leukemia and
related diseases. There are very small amounts of benzene present in unleaded petrol but
this is not considered high enough to be a leukemia risk. In some groups of workers, for
example farmers and agricultural workers, there appears to be an increased risk of
certain conditions, for example myeloma and lymphoma (www.cancernews.com). 
Ionizing radiation is another idea to the cause of the disease. This is radiation given
off by X-ray machines or by radioactive materials. High doses of radiation can definitely
increase the risk of leukemia. Most experts believe it is extremely unlikely that very
low levels of radiation can cause leukemia (www.cancernews.com). Some years ago it was
reported that children who had been exposed to medical X-rays before birth were more
likely to develop leukemia. The introduction of ultrasound has virtually eliminated the
need to use X-rays during pregnancy. Modern X-ray machines deliver a much smaller dose
and on the very rare occasions when a pregnant woman needs to be X-rayed special
precautions are taken to reduce the risk even further. Some studies have suggested that
there appears to be an increased risk of leukemia in children who live near electrical
power-lines or other electrical facilities. It is suggested that electromagnetic fields
may be capable of causing leukemia or accelerating the development of the condition
(www.cancernews.com). 
The fourth category is psychological. This category refers to how the patients see
themselves and to what they do once they have the disease. Psychologically, in the
beginning, the patient has no idea that they have leukemia. The initial symptoms that
they feel can easily be associated with other conditions. So their first response is not
to go to the doctor to get checked out. At first they would try home remedies until the
symptoms persist for a long period of time. This is the point in which the patient will
seek the help of a qualified physician. Once they have been diagnosed with the disease
the patient begins to feel that their life is over. This is because the overall survival
rate for the disease is only 5-7 years. This means that if you are diagnosed in the
beginning stages of the disease, doctors are only giving you up to 7 years to live even
with treatment (www.leukemia.org). It is very hard for these patients to return to their
normal roles in society because only 65 percent of the people diagnosed go into complete
remission. But with treatment and a strong support system, patient's ability to cope with
this disease is very high. They have a very good sense of personal competence and they do
not have to rely solely on others.
The last category is social interaction. In this category, you have to look at how the
patient's participate in social activities. In the first and last stages of this disease,
it is very hard for the patient to be social at all. In the first stages, the patient is
beginning their treatment in the hospital setting. This means that they will have to
spend 3-4 weeks in the hospital while they receive their chemotherapy treatments
(www.cancernews.com). At this time, the patient is very weak and ill and it is virtually
impossible for them to be social at this time. The middle stages are a lot better for
most patients. At this time, their disease is in some form of remission so they have a
chance to be more active with friends and family members. In the last stages, the
patients are back in the hospital and they are confined to their beds. It is sometimes
very hard for them to talk because they are so weak and in turn they no longer have a
strong sense of social interaction.
The "Multiple Causation Theory" is a way to classify the cause of illness into five basic
categories which together explain the origin and distribution of illness. I hope that by
me using this theory and it 's five categories, you are able to see this trend in the
social epidemiology of leukemia.
Multiple Causation Theory of Leukemia