Causes of cancer
Epidemiologists had identified many important causes of cancer by the early of 1980s. Many types of cancer vary in incidence by more than an order of magnitude between different populations and every type is rare in some part of the world. Many specific causes cancer are now known, the most common are by smoking, obesity and a few oncogenic viruses, but a large proportion of global variation for common cancers such as breast, prostate, colon and rectum remains unexplained (Peto J. , 2001). According to Richard Doll and Richard Peto, pollution accounts for 2% of all cancer cases and geophysical factors account for another 3% while 80% to 90% of cancers are caused by “environmental factors”. Environmental factors are the non-genetic factors which are smoking, diet, occupational exposure to chemicals and geophysical factors (naturally occurring radiation, man-made radiation, medical drugs and radiation and pollution.
Cancer is among the top disease classifications in the world. Even in a society as medically and technologically evolved as the United States we still suffer the effects of cancer. According to the experts from the American Cancer Society, the Cancer Treatment Centers of America, and the National Cancer Institute incidence of cancer is declining. This decline, however significant, does not alleviate the impact cancer continues to have on patients, their families, insurance companies, and the healthcare industry. This paper will define the various types of cancer; distinguish between malignant and benign tumors; identify the main categories of cancer; and with a specific focus on carcinoma types, treatment options, and prevention strategies will be explored. Carcinoma types covered are basal cell, squamous cell, renal cell, ductal, and acinar. Included is a section on nursing specific treatment. At the conclusion, the reader will have a basic understanding of cancer as well as a clear, generalized understanding of carcinoma.
Cancer occurrs by the production of multiple mutations in a single cell that causes it to proliferate out of control. Cancer cells often different from their normal neighbors by a host of specific phenotypic changes, such as rapid division rate, invasion of new cellular territories, high metabolic rate, and altered shape. Some of those mutations may be transmitted from the parents through the germ line. Others arise de novo in the somatic cell lineage of a particular cell. Cancer-promoting mutations can be identified in a variety of ways. They can be cloned and studied to learn how they can be controlled.
Proto-oncogenes are the genes tasked with the important job of controlling how often and how quickly cells divide. These genes can mutate into a different kind of gene known as oncogenes, and when this happens these genes begin to malfunction which can result in either being permanently activated or activated for more time than it is supposed to. This means that normally these genes would tell the cell when the appropriate times are to grow and when to stop growing, but because of their mutation they never tell the cell when to stop. The resulting over activation leads to the cell growing far larger than it is supposed to and can lead to cancer (cancer.gov, 2009). The cell that is now larger than it is supposed to be eventually grows to sizes that take up far more space than available, this same cell is now known as a tumor. As it continues to grow it begins to press up against its neighboring cells and tissues until the neighboring cells and tissues are unable to perform their specific tasks or are even killed. This inability to complete tasks due to lack of space or death can have extremely negative effects on the body, and it is due to the failure of the neighboring cells and tissues that cancer can kill a person (Phelan, 2010). ...
Rewinding to the root of the problem is unchecked cell reproduction for that is from where cancer arises. A cell manages to avoid the regular checks intended to monitor the cell’s normal development, resulting in it dividing continuously through mitosis until the abnormal cells aggregate to form a mass/primary tumour at the site of the initial cancer progression. At this point, these cells are not invasive nor metastatic, yet they may accumulate genetic alterations as they reproduce, giving them such capabilities. Metastasis may then occur as the cancer spreads to other organs by invading the circulatory or lymphatic system.
How does breast cancer develop? Breast cancer can first develop when proliferation of cells (or division of cells) begins to divide out of control. This can occur because of mutations in genes that regulate the proliferation of our cells. One gene that can be mutated is a tumor suppressor gene. This is a gene that in its normal state will turn off proliferation when needed. When this tumor suppressor gene is mutated then cells no longer have anything stopping them to proliferate uncontrollably. This uncontrollable division of cells is cancer. Another gene that could be mutated is a Proto-Oncogene. An oncogene is a proto-oncogene that has been mutated to accelerate proliferation, which in response causes cancer. Another tumor suppressor gene is called the p53 gene. This is a tumor suppressor gene that acts as a check point in cellular proliferation. A mutation in the p53 gene is the most common genetic change that is linked to breast cancer (Clark, 2005).
Cancer is caused by a defect in genes that control cell growth and division. Things like smoking, chewing tobacco, and radiation exposure can cause these defects. Most cancer cells have a defect in the gene called p53. The gene p53 stops the cell cycle until all the chromosomes have been duplicated right, but when it is defective or damaged it makes cells lose their information needed to respond to signals that normally control growth.
In this seminar (essay) we will be discussing cancer, specifically lung cancer, what it is, how cells become cancerous, and what carcinogens are. I will begin by telling you what a cell is. A cell is most frequently referred to as the basic building block of life. The human body is made up of millions and millions of cells that provide structure for the body and carry out many functions for everyday living. Cells grow and divide all the time and sometimes become damaged. This is when they become a mutation, which will continue to affect the normal growth of cells. As a mutated cell continues to divide, it only becomes more damaged. After about the fourth mutation is produced, growth becomes uncontrolled and this leads to a tumor. This large mass of cells is made up of mutated cells that can be benign or malignant. Benign cells are not cancerous; malignant cells are cancerous. A benign growth can occur in any part of the body and are small and harmless. It is the malignant cell growths that grow rapidly without knowing when to stop. These cells have the potential to grow into large masses and turns into what is known as cancer. When these large masses spread to other parts of the body they are known as metastases.
The Initiation step of carcinogenesis is a rapid process and in this process there is a direct involvement of carcinogen-binding and consequential damage to DNA which results in an irreversible mutation. The Initiation step is followed by Promotion step in which “clonal expansion” of initiated cells is noticeable. This feature is a result of induction of initiated cells by mutagenic agent...
More than 1 in 3 people in the UK will develop some form of cancer during their lifetime (1). This shows how important treating cancer is, in the best way possible.