Science Essay, Research Paper
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Cancer Right now, cancer is one of the most feared diseases in the world. In
the early 1990s almost 6 million new cancer cases developed and more than 4 million deaths
from cancers occurred. Also more than one-fifth of all deaths were caused by cancer and it
has been predicted, by the American Cancer Society, that about 33% of Americans will
eventually develop this disease. This is a huge disease that is killing people all over
The field of cancer study is called Oncology. The government has spent
billions of dollars on research of this fatal disease. Cancer is the most aggressive
disease of a larger class known as neoplasms. Neoplasms do not fully comply with the parts
of the cell that control the growth and functions of the cell. These cells eventually
become abnormal growths and can be recognized as not normal tissue. These traits are
passed down as the cell reproduces therefore spreading the cancer.
Neoplasms are generally classified into two groups: malignant and
benign. Malignant tumors, or abnormal tissue, grow more rapidly than benign tissue and
they invade normal tissue. Benign tissue is structured similar to normal tissue while
malignant tissue is abnormal and has an unstructured appearance. Of greater importance,
benign tissue does not metastasize, or begin to grow in other sites, like malignant tumors
do. Cancer always refers to metastasized tumors but the term tumor is not always
necessarily cancer. A tumor is any living tissue that is distinguishable as abnormal
After a cancer forms, it can also change from a benign to a malignant state, therefore
making the cell grow at a more rapid rate. The development of the cell starts when it
forms notable abnormalities in chromosomes and then multiplies exceedingly. Then
metastasis usually occurs and generally causes the death of the host.
There are many different cancers which form on just about all parts of the body. In the
US, skin cancer is the most common cancer, then prostate cancers in males, and then breast
cancer in women. Leukemia is clearly the dominant cancer in children. The number one
killing cancer in the world today is lung cancer, mostly caused by the smoking of
cigarettes. Some researchers have stated that if Americans stopped smoking, lung-cancer
deaths could disintegrate within two decades. Stomach cancer is the second most fatal
cancer in males and Third is the leading cancer in women, breast cancer.
The prevention of cancer rides upon what is known about the causes. Any agent that causes
cancer is called a carcinogen. Carcinogens are generally classified into three groups-
chemical, biological, and physical.
Chemicals that cause cancer have many different molecular structures and can be just about
any type of chemical. Some substances that cause cancer are complex chemicals and gases,
certain metals, drugs, hormones, substances in molds and plants and many more. Many
nitrosamines, or simple organic oxides of nitrogen, are carcinogenic. That and
hydrocarbons are carcinogens in cigarette smoke and increase the risk of lung cancer. Also
another chemical gas, vinyl chloride, gas has been found to be an agent of sarcoma of the
blood vessels in the liver. Many drugs as well as alkylating agents used to treat cancer
are carcinogenic. Even though these chemicals break the DNA of cancerous cells, which
kills them, it also induces cancer in normal cells. Some hormones created in humans can
also cause cancer. High levels of estrogen, which is marked as a female hormone, can
increase the chances of getting a cancer of the uterus (in women). Aflatoxin B is a
substance produced by the mold Aspergillus that causes a number of c
ancer, but generally liver cancer. Many carcinogens have not been discovered but research
is being done to discover other carcinogens to keep people aware and safe.
There are also many different biological agents which cause cancers. The most common
biological agents are the oncogenic viruses that commonly bring about the formation of
neoplasms in some smaller animals. Also some of these viruses are thought to cause human
cancers, and one has even been proven to cause leukemia. These viruses can be split into
DNA viruses and RNA viruses, depending on their genetic structure. The DNA viruses
generally insert the genetic information straight into the cells of their host. The RNA
virus, contrasting, requires that the genetic information be transcribed into DNA by an
enzyme, called reverse transcriptase, provided by the virus. All onconogenic viruses have
one or more genes that are needed for the transformation of the infected cell into the
neoplastic cell. These genes, called oncogenes, are best portrayed in the genomes of
oncogenic RNA virus. It is now seen that the oncogenes have close relation with the
counterparts in the normal cells which they infect. The oncogene, non
etheless, has a different structure and appears to be activated and expressed abnormally
by one mechanism or another, leading to transformation in the cell. Some oncogenic viruses
may activate the normal cellular counterparts of oncogenes, called c-oncogenes, thus
causing the neoplastic transformation to occur. Similar reactions may be a result from the
action of chemicals or radiation or both.
Ultraviolet and high-energy radiation are also agents for some types of cancer. A bond
exists between exposure to the sun’s ultraviolet rays and the occurrence of skin
cancer in humans. Some cancers caused by radiation are leukemia, along with cancers of the
thyroid, breast, stomach, uterus, and bone. Consequently everyday diagnostic tools such as
the X ray are used very carefully so that a person is not overexposed. Physically induced
sarcomas can also be induced when films or disks are enclosed under the skin, as done in
experimental animals. After the implant has been in the animal for many years, sarcomas
usually develop around the implant. If the implant is pulverized or its structure is
markedly altered before insertion, no sarcomas develop. This shows that the physical
structure causes the cancer, other than the chemical composition.
Even though it is unknown why cancer happens in some people and not in others heredity
seems to have an effect in some forms of cancer. Because of this, family history may be
significant in predicting and diagnosing cancer.
Prevention is the best way to avoid cancer. Since the majority of cancer is related to the
environment, it would be best to identify and control these factors. There are two tests
to discover carcinogens. The Ames test measures the ability of a substance to cause
mutations in bacteria and is more than 90 percent effective. The alternative is animal
testing. It is exhausting and expensive work but it is the only certain way to be sure if
a particular agent is carcinogenic.
One of the most important ways to protect yourself is early detection. It is stressed that
you get treatment as soon as possible. The American Cancer Society has come up with seven
warning signs of cancer to help you identify cancer symptoms and get help early. They are:
1.a change in bowel or bladder functions; 2.a sore that does not heal; 3.unusual bleeding
or discharge; 4.a thickening or lump on the body; 5.indigestion or trouble swallowing;
6.an obvious change in a wart or mole; and 7. A nagging cough or hoarseness. If one or
more of these symptoms are present a person is advised to see a doctor immediately.
If treatment of a cancer is to be successful, the diagnosis must be as
early as possible. Though no tests have been discovered to detect all cancers, there are
tests to pick up some. A pap test is used to search for cancer of the uterine cervix.
Mammograms are used to detect breast cancer and blood and stool tests are used to find
colon cancer. There are many other tests besides these to test for all different types of
cancer. There are really three different types of cancer. Surgical removal is the first,
it is the most basic treatment. It is used to remove the cancerous legions in the body.
The second is radiation therapy, which uses radiation to try and kill the tumor. One of
the main problems with that is not only does it kill cancerous tissue, it also kills
healthy ones. The third way to treat cancer is chemotherapy, which is treatment by
chemical agents. The chance of complet