Free Causes Of Cancer Essay Example

Cancer is a terminal condition characterized by abnormal cell growth in the body. It is mostly associated with tumors that often put the patient at risk of spreading to other body parts. Scientific studies have not been conclusively clear on the causes of cancer. There have been several hypotheses about factors that have contributed to this disease. Most studies show that smoking is a major factor that contributes to abnormal cell growth. Obesity, lack of physical exercise, exposure to radiation and some infections such as hepatitis are also part of the factors attributed to cause cancer in humans. There are more than one hundred types of cancers that affect human beings. The most common types are lung cancer, prostate, colorectal cancer, and stomach cancer. Women are more affected by breast cancer and others such as lung cancer, colorectal cancer and cervical cancer. This work is a literature review on the 3 journal articles on the causes of cancer and the different opinions on the issue.
Cancer has been suggested to develop due to the defectiveness of cell reproduction, a result of the active involvement of viral genes. This process is usually similar to genetic engineering. According to Chan, cancer cells are just but amalgamations of genetically modified organisms. In cancer development, there are two groups. The genetic engineering of a viral genetic relic brings up group one group of the cells. An example of such relic is endogenous retroviruses which came about as a result of oxygenation of the atmosphere. This group is referred to as Genetically Modified Organisms from Viral Genes (GMOVS). The second group arises by the making of genes of ancient eukaryotes which were there before the oxygenation of earth. These are known as genetically modified organisms from ancient Eukaryotic genes. (GMOE) (Chan). This study suggests that eukaryotes existed long before the presence of free oxygen on earth. When the process of oxygenation began, many kinds of cells that had oxidative metabolisms were produced. Viral genes, although mostly inactive in human life may at times become active in the development of the placenta when the need arises. In cell regeneration, some cells may be abnormal and unhealthy. This therefore results in a defective cell which must either be repaired or if it is not possible the immune system eradicates the cell and if this fails, the defective cell develops into a GMO that may be cancerous in nature depending on whether the viral genes of the cell are actively involved. Cancer cells are as a result of a combination of these GMIO’s.
The rates of cancer have been shown to be reduced by the avoidance of smoking. Smoking causes an increased rate of cell division that may lead to the mutation of abnormal cells. Other activities that have been shown to reduce cancer development include increase in physical activity, reduction of sun exposure and reduction of alcohol intake. Breast cancer has been known to be reduced by efforts to modify sex hormone levels. The question is what do these issues have to do with the causes of particular types of cancers? The cause of cancer can be attributed to mutations of genes. The mutations of suppressor gene P53 was shown to have about half of human tumors. The gene’s deactivation causes uncontrolled cell division. This in turn may give rise to abnormal cells that are cancerous. The DNA lesions are another cause of cell mutations. Especially whereby a cell divides, the likelihood of DNA damage is high. An exogenous mutagen produces an increment in lesions over the background rate of endogenous lesions. . Stem cells are normally the point of concern in cancer development. These are not discarded, whereas their daughter cells are. When the cell division rates of the stems cell is increased, this leads to mutation which subsequently causes cancer. Cells that do divide rarely cause cancer. Increase in cell division resulting to cancer can be as a result of different factors, such as increased levels of particular hormones, excess calories, chronic inflammation, or chemicals at doses causing cell division. (Ames, Gold and Willett)
Studies have shown that external factors are major causative agents for cancer. However, there are molecular and cellular levels of cancer causation that regards genetics. Human cancers are caused due to combination of factors. These include the actions of chemical and viral agents. Cancer is developed in 3 stages, initiation, promotion and progression. The transition between the stages is propelled by the external factors such as bio chemical and biochemical agents
There are two groups of compounds, aromatic amines and polycyclic aromatic hydrocarbons, which deform DNA and RNA transcriptions. The implication of this is that the deformed cells cause abnormal cell replication that leads to cancerous tumors. The second stage, of tumor promotion is caused by the action of the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate. This agent and related compounds activate a specific cellular enzyme, protein kinase C (PKC). This causes several actions which include alterations in the function of membrane-associated ion channels and receptors, alterations in gene expression and, changes in cellular differentiation and proliferation. The outcome is growth of the tumors is encouraged and this mutation leads to cancer in the human body (Weinstein).
The causes of cancer from the above Literature sources are shown to be similar. The voices in the different articles are as follows. The first article by Chan is a single voice. It is characterized by the authors own hypotheses that is yet to be validated, that is the opinion that cancer is majorly caused by the amalgamation of genetically modified organisms. He gives various trial suggestions that may validate his hypothesis. The Second article by Ames et al is plural in nature; the authors depend on research carried out in various laboratories regarding the causes of cancer. Their concentration is on Mutation and DNA deformation as causes of tumors in the human body. They also refer to previous studies on the issue. The voice in the last quoted article is a combination of voices. His interest is shown to find prevention for cancer. He asserts that external factors are a major contribution for the disease and therefore it can be prevented. The author refers to scientific studies on the issue and is open to more research on the matter. However, the findings of the three literature reviews are similar as they attribute cancer to genetic cell division factors while recognizing the promoting external factors for the development of the disease.

Works Cited

Ames, Bruce N, Lois Swisky Gold and Walter C Willett. "The causes and prevention of cancer." Review (1995): 5258-5265.
Chan, John Yuen. "Hypotheses of Cancer Weakening and Origin." Journal of Cancer (2015): 457-463.
Weinstein, Benard. "The Origins of Human Cancer: Molecular Mechanisms of Carcinogenesis and TheirImplications for Cancer Causes and Prevention." Cancer Research (1988): 4135-4143.