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Chronic Inflammation as a Risk Factor for Colon Cancer?

Essay 2016 6 Pages

Health - Public Health

Excerpt

Inhalt

Introduction

Chronic Inflammation as a Risk Factor to Colon Cancer

Pathophysiology of Chronic Inflammation

Extent of Chronic Inflammation's Contribution to Cancer Etiology

Relation of Genetics and Chronic Inflammation

Conclusion

References

Introduction

Colon cancer seems to have become an enormous challenge to global public health systems although its prevalence is high in high income countries such as the U.S, Canada and Western Europe. Boushey and Haggar (2009) report, “In North America, New Zealand, Australia, and Western Europe, mortality from colorectal cancer in both men and women has declined significantly; however, in some parts of Eastern Europe, mortality has been increasing by 5 to 15% every 5 years” (p. 4). In the U.S, colon cancer is ranked second among the leading cancer-related causes of mortality, and it is the third most common cancer in men and women. CDC reports that 131. 607 people in the U.S were diagnosed with colorectal cancer while 52,045 people died, including 24,972 women and 27,073 men, in 2010 (CDC, 2010).

Early this year, the incidence of colon cancer was found to be slightly reduced compared to the previous year and the total number of new cases of colon cancer was found to be 102, 480 although the total number of deaths related to colon cancer were estimated to reach as high as 50,830 by the end of 2013. Currently, there are more than 1 million survivors of colon cancer in the U.S (American Cancer Society, 2013).

In the U.K, 15,708 people died of colon cancer in 2010 while 40,695 new cases were diagnosed with colon cancer in the same year, accounting for 10% of all cancer deaths in the country. Epidemiological reports indicate that colon cancer is the third-leading causes of cancer-related deaths in U.K (Cancer Research UK, 2013).

It has been found out that the prevalence of colon cancer is related chronic inflammation, which serves as one of the most significant risk factors. Therefore, this research paper will discuss the relationship between chronic inflammation and colon cancer. It will discuss how chronic inflammation causes colon cancer, primarily with regard to etiology, and it will also discuss genetics is related to chronic inflammation.

Chronic Inflammation as a Risk Factor to Colon Cancer

Colon cancer is believed to be caused by chronic inflammation of the bowel. In most cases, chronic inflammations of the bowel are caused by inflammatory bowel disease (IBD). This is an inflammatory disease which includes Crohn’s disease and ulcerative colitis. However, it is worth noting that inflammatory bowel disease manifests variations from irritable bowel syndrome (IBS) in terms of pathophysiology and their relation with colon cancer. The latter is not believed to have any significant correlation with colon cancer, but inflammatory bowel disease has already been proven to be one of the most principal risk factors responsible for the occurrence of colon cancer.

Pathophysiology of Chronic Inflammation

In inflammatory bowel disease, colon becomes inflamed for a long duration leading to the development of dysplasia in which cells lining the colon become morphologically distorted to appear abnormal under microscopic view.

Despite the scarce clinical evidence on the occurrence of inflammatory bowel disease, recent research findings indicate that chronic colon inflammations are caused by pathogens and genetic factors. One of the most etiological causes of chronic bowel inflammation is the invasive bacteria known as Helicobacter pylori which occur abundantly in natural habitats, primarily in the soil. It is believed that about 90% of the global population has these bacteria, but it exists in inactive state unless physiological conditions in an individual’s body changes to enable the bacteria become pathogenic. In most cases, retention of digestive wastes in the colon over a long duration causes H. pylori to release toxins which accumulate in the colon. In the long run, these toxins causes inflammation of the cells lining the colon; thus, causing ulcerative colitis.

On the other hand, macrophages at the inflammation site are believed to react with Oxygen; thus, generating reactive Oxygen species (ROS) which are carcinogenic (Bagchi, Raychaudhuri & Roy, 2012). As a result, adenomatous polyps develop on colon walls and these advance to colon cancer when they are not removed early in the initial stages after detection through screening, especially by the use of flexible sigmoidoscopy.

Extent of Chronic Inflammation's Contribution to Cancer Etiology

It has been found out that inflammation of the colon does not necessarily lead to colon cancer, but the extent of the development of dysplasia determines cancer etiology. In most cases, chronic inflammations of the bowel do not lead to the onset of colon cancer. For instance, irritative bowel syndrome may persist over a long period, but it does not cause colon cancer. Clinical studies indicate that, only inflammatory bowel disease is related to an increased risk of colon cancer, but not all cases of the diseases end up causing cancer in the affected people.

However, it is worth noting that a single episode of bowel inflammation is not adequate to cause colon cancer. It is believed that chronic inflammations lead to the development of neoplastic polyps after a prolonged period exceeding 5 years. Boushey and Haggar (2009) report “a long latency period, estimated at 5 to 10 years, is usually required for the development of malignancy from adenomas” (p. 6).

In regard to etiology, chronic inflammation causes colon cancer in two principal ways which are related to inflammatory bowel disease. Crohn’s disease is one of the most principal causes of chronic inflammations of gastrointestinal tract, and it affects all parts of the GIT from the mouth to anus. In colon cancer, Crohn’s disease causes inflammation of the bowel wall which lead to the development of dysplasia on the full thickness of the colon, and this increases the risk of colon cancer. On the other hand, ulcerative colitis causes inflammation of the colon mucosa which in turn causes dysplasia of the cells lining the colon. In general, chronic inflammation such as inflammatory bowel disease leads to the development of villous and tubular adenomas which are commonly referred to as neoplastic polyps of the colon. These neoplastic polyps are known to be precursor lesions of most forms of colorectal cancer, and most individuals who have previous personal history of adenomas show increased risk of suffering from colon cancer, as well as, rectal cancer (Boushey & Haggar, 2009).

Relation of Genetics and Chronic Inflammation

Epidemiological reports indicate that chronic inflammation, primarily the inflammatory bowel disease is related to genetic factors among different people. This implies that, people with family history of inflammatory bowel disease have an increased risk of developing colon cancer over time. It is reported that 1 in 5 people with colon cancer come from families with history of inflammation bowel disease (Herceg & Ushijima, 2010). This is, probably the principal reason as to, why colon cancer has been linked to genetic causes although there are other risk factors involved in the occurrence of the disease.

It is believed that genetics plays a significant role in the development of colon cancer because; most people who suffer from inflammatory bowel disease end up developing colon cancer over time. This conclusion can be reaffirmed by the fact that colon cancer occurs after a prolonged period of the existence of inflammatory bowel disease, but not vice versa. Ordinarily, colon cancer does not cause inflammatory bowel disease. In general, the relative risk of colon cancer among people with inflammatory bowel disease has been found to be four to twenty folds compared to colon cancer incidences in patients who do not have a personal history of IBD (Boushey & Haggar, 2009).

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Details

Pages
6
Year
2016
ISBN (eBook)
9783668575820
File size
409 KB
Language
English
Catalog Number
v381245
Institution / College
Egerton University
Grade
1
Tags
cancer colon cancer

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Title: Chronic Inflammation as a Risk Factor for Colon Cancer?