Cancer Essay, Research Paper
CANCER CAUSES AND TREATMENTS.
Tejmeena. Aujla
Biology Coursework
Assessment 1E Communication Skills Assessment
20-02-2001
Cancer Causes and Treatments
Introduction:
This essay is about cancer; it s causes and methods of treatment. I have collected a wide variety of information from a wide variety of sources.
I. What is cancer?
A.
1. TUMOURS-benign or malignant
2. Names of the different types of cancer in different parts of the body
II. Causes
A. What factors cause cancer.
III. Treatments
Conclusion: There are many different types of cancers caused by many different factors. At the moment there is no proper cure but research is continually being carried out to find a cure.
Cancer Causes and Treatments
What is Cancer?
Cancer is a group of many related diseases that begin in cells, the body s basic unit of life.
The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process keeps the body healthy. Sometimes, however, the cells keep dividing when cells are not needed. These extra cells form a mass of tissue, called a growth or TUMOUR.
There are two types of tumours. These can be BENIGN or MALIGNANT.
Benign tumours are NOT cancers. They can often be removed and in most cases never return. Cells from benign tumours don t spread to other parts of the body. They are rarely a threat to life.
Malignant tumours ARE cancer. Cells in these tumours are abnormal and divide without control or order. They can invade and damage nearby tissues and organs. Also, cancer cells can break away from the malignant tumour and enter the bloodstream or the lymphatic system. That is how cancer spreads from the original cancer site to form new tumours in other organs. The spread of cancer is called metastasis.
Leukaemia and lymphoma are cancers that arise in blood forming cells. The abnormal cells circulate in the blood stream and lymphatic system. This may also invade body organs and form tumours.
Most cancers are named from the organ or type of cell in which they begin. E.g. Cancer that originates in the lungs is called lung cancer, and cancer that begins in the cells in the skin know as melanocytes is called melanoma. When cancer spreads (metastasizes), cancer cells are often found in nearby or regional lymph nodes (sometimes called lymph glands). If the cancer has reached these nodes, it means that the cancer cells have spread to other organs, such as the liver, bones or brain. When cancer spreads from its original location to another part of the body; the new tumour has the same kind of abnormal cells and name as the primary tumour. For example, if the lung cancer spreads to the brain, the cancer cells in the brain are actually lung cancer cells. The disease is called metastasis lung cancer (it s not brain cancer).
Possible Causes and Prevention of Cancer.
The more that is learnt about what causes cancer, the more likely it is that ways will be found to prevent it. In the laboratory scientists explore possible causes of cancer and try to determine exactly what happens in the cells when they become cancerous. Researchers also study patterns of cancer in the population to look for risk factors, conditions that increase the risk that cancer might occur. They also look for protective factors, things that decrease the risk.
Cancer is not contagious. It develops over time. It is a result of a complex mix of factors related to life style, heredity, and environment. A number of factors that increase a person s chance of developing cancer have been identified. Most types of cancer are related to the use of tobacco, what people eat and drink and exposure to ultraviolet (UV) radiation from the sun, and to a lesser extent, exposure to cancer causing agents (carcinogens) in the environment and the work place. Some people are more sensitive than others to certain
Still, most people who get cancer have none of the known risk factors. And most people who do have risk factors don t get the disease.
Some cancer risk factors can be avoided. Other s such as inherited factors are unavoidable, but it is helpful to be aware of them.
These are some of the factors that increase the likelihood of cancer:
Tobacco. Smoking tobacco, using smokeless tobacco, and begin regularly exposed to environmental tobacco smoke are responsible for one-third of all cancer deaths in the USA each year. Tobacco use is the most preventable cause of death in this country.
Smoking accounts for more than 85% of all lung cancer deaths. For smokers, the amount of tobacco smoked each day, the number of years they have smoked, the type of tobacco product, and how deeply they inhale. Overall for those who smoke one packet a day, the chance of getting lung cancer is about 10 times greater than for non-smokers. Cigarette smokers are more likely than non-smokers to develop several other types of cancer, including oral cancer and cancers of the larynx, oesophagus, pancreas, bladder, kidney, and cervix. Smoking may also increase the chances of developing cancer of the stomach, liver, prostate, colon, and rectum. The risk of cancer begins to decrease soon after a smoker quits, and the risk continues to decline gradually each year after quitting.
Diet . Researchers are exploring how dietary factors play a role in the development of cancer. Some evidence suggests a linkage between a high-fat diet and some cancers.
Ultraviolet (UV) radiation. UV radiation from the sun causes premature aging of the skin and skin damage that can lead to skin cancer. Artificial sources of UV radiation, such as sun lamps and tanning booths, also can cause skin damage and a probably increased risk of sun cancer.
Alcohol. Heavy drinkers have an increased risk of cancers of the mouth, throat, oesophagus, larynx and liver.
Ionising radiation. Cells may be damaged by ionising radiation from x-ray procedures, radioactive substances, rays that enter the Earth’s atmosphere from outer space, and other sources. In very high doses, ionising radiation may cause cancer and other diseases. Studies of surviers of the atomic bomb in Japan show that ionizing radiation increases the risk of developing leukaemia and cancers of the breast, thyroid, lung, stomach and other organs.
Chemicals and other substances. Being exposed to substances such as certain chemicals, metals or pesticides can increase the risk of cancer. Asbestos, nickel, cadmium, uranium, radon, vinyl chloride, benzidene, and benzene are examples of well known carcinogens. These may act alone or along with another carcinogen, such as cigarette smoke, to increase the risk of cancer.
Close relatives with certain types of cancer. Some types of cancer (including melanoma and cancers of the Brest, ovary, protease, and colon) tend to occur more often in some families than the rest of the population. It is often un clear whether a pattern of cancer in a family is primarily due to hereditary, factors in the family s environment or lifestyle, or just a matter of chance.
TREATMENTS
Cancer is one of the leading causes of death in the industrially world, yet it is by no means incurable, particularly in the case of certain tumours, including Hodgkin s disease, acute leukaemia, and testicular cancer. Cures are sometimes achieved with specialised treatments, such as surgery, chemotherapy with cytotoxic drugs, and irradiation, or a combination of all three. Monoclonal antibiotics have been used therapeutically against some cancers, with limited success. There is also hope of combining monoclonal antibody with a drug that will kill the cancer cell to produce a highly specific magic bull drug. In 1990 it was discovered that the presence in some patients of a particular protein, p -glycoprotein, actively protects the cancer cells from the drugs intended to destroy them. If this action can be blocked, the cancer should become far easer to treat. Public health programmes are concerned with prevention and early detection.