Реферат: Cancer In Detail Essay Research Paper Discuss

Cancer In Detail Essay, Research Paper

Discuss social, ethical and biological issues associated with cancer Cancer is

one of the most complex and devastating diseases that claim the life of many

humans. Today there are one in three people worldwide who are affected by

cancer, and almost 60% of these people will almost certainly die. 7000 New

Zealanders die every year from this disease. It is the second largest killer

next to heart disease. Cancer does not just affect certain groups of people, it

can affect anybody and it is not just one disease, it refers to more than a

hundred diseases. Cancer is caused by carcinogens. At present, hundreds of

chemicals are known to induce cancer. Normally, the body?s cells divide in an

orderly way, allowing the body to grow and to heal after injury. Damage or

mutations that occur to the proto-oncogenes (POG) and tumour suppresser Genes (TSG)

in the genetic material (DNA and RNA) by these carcinogens bring about Cancer,

which causes cells to have less control of cell division and differentiation.

POGs lead to changed cells or transformed cells and cause excessive cell

division. Further mutations cause the cells to become immortal. These cells

continue to divide and form a ball of cells. These cells require a lot of energy

and fluids flowing to maintain the high rate of the cell division. When these

balls become too large for fluids to flow through, the middle of the ball dies.

TSG?s act as anti-proto-oncogenes, they regulate the rate of cell division.

POG?s and TSG?s constantly compete to overpower each other. These TSG?s

can be mutated and this brings about a change in the control mechanism of cell

division. Cells are stimulated to divide through a growth factor. Growth factor

molecules bind to cell membranes of cells and send a chemical message to a

receptor in the cell membrane. The receptor sends a message through the

cytoplasm to the nucleus to stimulate cell division. Sometimes when these growth

factors are absent the receptor in the cell membrane is mutated to send out the

message to the nucleus. Cells are also stimulated to divide through the two

proteins, cyclins and cyclin-dependent kinases. When these two join together,

this stimulates cell division. These proteins act on the growth inhibitor

proteins P53 and PRP, which are growth inhibitor proteins. Tumours may be

malignant, spreading or benign, non-spreading. Malignant tumours are aggressive,

invasive, and mobile. They invade healthy tissue and continue to divide. The

original cancer is called the primary tumour. If the tumour is malignant, the

disease may develop in other parts of the body where secondary tumours may form.

This is known as metastasis. Cancer causes illness through local growth, spread

to distant organs, and overall effects of the disease on the individual.

Treatments of cancer vary. Tumours may be surgically removed if they have not

metastasised. Other methods are usually used if the tumour has metastasised. For

chemotherapy drugs are used to kill cancerous cells as they divide. Radiotherapy

is another standard way of treating cancer, ionising radiation aimed at the

tumour will prevent the cells from dividing further. So what makes cancer more

special than other diseases? The answer is that there is no cure and scientists

are not optimistic of finding one in the near future. Today people are far more

knowledgeable about cancer and how it may be avoided than 10 years ago. It has

now been found that as many as 80% of all cancers may be avoidable. The most

common types of cancer in New Zealand are female breast (14%), male prostate

(14%), trachea, bronchus, and lung (12%) and colon (11%) Given that such a large

proportion of cancers may be avoidable, why isn?t there a reduction in cancer

incidence? This may be because our educational programs are not appropriate and

perhaps even due to people?s ignorance. Female breast cancer and male prostate

cancer can almost always be cured if detected and treated in time. For the early

detection of female breast cancer appropriate programs such as monthly mammogram

and breast self-tests have been introduced. But I believe that male prostate

cancer has not been addressed enough (more?). 80% of lung cancers have been

found to be caused by smoking. If smoking is such a huge cause of lung cancer

that kills almost 150 New Zealanders every year, why can?t it be banned? This

is because large multimillion-dollar tobacco companies such as Wills and Benson

and Hedges have very successful advertising campaigns mainly sponsoring sports

teams. Even though it seems like tobacco advertising has decreased, it was only

last year when Benson and Hedges sponsored the triangular cricket series in

Australia. With such a lot of income coming into the tobacco industry they

cannot be taken on by small individual and private research organisations. It is

also the ignorant buyer?s fault for purchasing tobacco even though it has been

proven to be addictive and cancer causing. More than any other ethnic group in

New Zealand, Maori girls have been found to smoke the most. This could be

because they do not receive adequate support from home and family or maybe

because most have a high rate of poverty since they are a minority. In New

Zealand where certain cancers are at the highest incidence in the world, the

government spends over 110 million dollars each year on treating patients with

smoking related diseases including lung cancer. If more money went into

preventing out young and Maori teenagers picking up the smoking habit, the cost

might be reduced and lives saved. Today billions of dollars are spent throughout

the world on cancer especially in developed countries of the western world where

a lot of money is freely available. Most of this research is carried out by

private organisations and therefore ethnic minorities appeal to be included in

their research. Dietary factors underlie as many as 35% of all cancers. Of this

35%, almost 80% of the patients are colon cancer patients. The government has

taken on a major preventative scheme, introducing the 5+a day dietary standards

to improve the intake of more fruits and vegetables into people?s daily diets.

This aims at reducing bowel cancer in New Zealand, which will no doubt save

lives. For these reasons, cancer is a contemporary issue. Biological, ethical

and social issues surround it. It also seems that a lot has been done to prevent

it but there is so much further to go, and this would ultimately reduce the

number of lives that the cancer claims.

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