Background Colon cancer is a common fatal disease; it is the fourth most common cancer in the UK, in 2013 there were around 41,100 new cases of colon cancer. Worldwide, an estimated 1.36 million new cases of colon cancer were diagnosed in 2012, with incidence rates vary across the world. Since the late 1970s, Overall Colon cancer incidence rates have increased by 14% in Great Britain. Although colon cancer mortality rate dropped by around 14% over the last decade, colon cancer still the second most common cause of cancer death in the UK after lung cancer among men and women.(1) Colon cancer can be treatable when diagnosed and removed at an early stage; however, 5-year survival is less than 10% of patients with the advanced metastatic disease. Nearly half of patients with colon cancer develop metastatic cancer at some stage. Chemotherapy such as 5-fluorouracil is the first line treatment of metastatic colon cancer because surgery is limited to patients who have no metastasis outside the liver or those who would have an appropriate amount of liver left after the surgery.(2) Colon cancer pathogenesis has been studied and revised extensively over the past two decades, …show more content…
(1) The chromosomal instability pathway; which leads to several changes in copy number and structure of the chromosome leading to mutational Inactivation of Tumour-Suppressor Genes such as APC, P53, and SMAD4. Also, it leads to activation of Oncogenes such as KRAS, PTEN. , (2) the microsatellite instability pathway that causes Inactivation of genes required for DNA mismatch repair such as MLH1 gene through promoter methylation and epigenetic silencing. (3) The cytosine-phospho-guanine island methylator phenotype pathway. This understanding forms the basis for the design of molecular diagnostics, novel targeted therapy and has directly influenced clinical care by providing both prognostic and predictive value.
...ozzi E, Biffoni M, Todaro M, Peschle C, et al. Identification and expansion of human colon-cancer-initiating cells. Nature. 2007;445(7123):111-5.
Cancer is one of the 9 National Health Priority Areas (NHPA), areas which account for a significant portion of the burden of disease, but have sizeable potential for improvement. In Australia, CRC is the second most common cancer, after prostate (in men) and breast cancer (in women) (AIHW, Cancer incidence projections). The incidence has gradually increased (by 13% in males from 1982-2007) (AIHW, Cancer in Australia an overview). This is compounded by the ageing population and population growth, with 14,860 new cases in 2010 (http://www.cancer.org.au/about-cancer/types-of-cancer/bowel-cancer). This graph demonstrates this upward trend ((AIHW, Cancer incidence projections):
Surgery is the most common treatment for all stages of colon cancer. Cancer cells may be removed by one of the below procedures:
...plicates the identification of the loss of tumor suppressor gene (TSG) is epigenetic changes in the gene promoter. Hypomethylation of DNA and hyperacetylation of histones in the promoter region leads to successful transcription of the DNA. Therefore, any alteration in either of the two will disrupt the gene transcription.
Colorectal cancer, or CRC, affects African American men and women more than Caucasians, at a rate 20% higher. This is concerning when faced with the mortality rates among African Americans, 28% higher for women and 14% higher for men than for Whites. African Americans are also more likely to be in later stages of the disease when diagnosed. There is a need to study and evaluate why these factors exist, as proper screening and early diagnosis can severely impact survival rates for CRC. One study attempts to find the solution through testing, however, this study slightly discredits itself along the way.
Colon cancer is the third most common cancer in men and women, responsible for more than 57,000 deaths in 2001 alone. Colon polyps, which can lead to colon cancer, are found in about 30-40% of people aged 60 or older- and the risks of polyps increase with age” (Lerche Davis, 2003). Most cases of colon cancer start as small adenomatous polyps. Many people experience no signs or symptoms in the early stages of colon cancer. Some signs and symptoms can include diarrhea, constipation, or any change in consistency of your stool that continues for longer than a month. Any bleeding from the rectum or blood found in the stool can also be a sign of colon cancer. Continuing abdominal pain, cramps, gas, weakness, fatigue and unexplained weight loss could all be signs of rectal cancer in the patient (Staff,
Hypermethylation of CpG islands at tumor suppressor genes turns them off, while hypomethylation leads to the instability and inappropriate activation of oncogenes and transposable elements. Methylation can be directly related to genetic mutations, an example of this case is methylated cytosine. Methylated cytosine mutates spontaneously in vivo through deamination to give thymine. According to Andy Bannister (n.d.), “37% of somatic p53 mutations and 58% of germ line mutations occur at methylated...
Thought to be an oncogene, a gene that has potential in transforming normal cells into tumor cells, p53 was regarded as the most prominent tumor suppressor gene [1]. P53 is a gene which signals apoptosis (programmed cell death) if a cell cannot be repaired due to an extensive amount of damage. As stated in the textbook, p53 regulation occurs by an E3 ubiquitin-protein ligase known as MDM2 [1]. "Controlling the controller" is a statement that describes the molecular interaction where the presence of MDM2 targets the p53 for proteosome via degradation. With three main checkpoints in cell cycle, the literature states p53 functioning from G1 into S phase in a chaotic cell [2]. The normal state of cells is to keep p53 levels low in order to prevent uncontrolled apoptosis and random cell cycle arrest from occurring. In a further note, although p53 promotes apoptosis and cell cycle arrest, cancer may result from p53 unable to recognize the problematic site. In turn, a mutation in p53 may result engaging in new activities. These activities include cellular transformation, tumor metastasis,...
Colon cancer develops in the part of the gastrointestinal tract that absorbs water and minerals before waste products are disposed via the rectum. In women endometrial cancer is related to colon cancer. This type of cancer is the second leading cause of death due to cancer in the United States. Over one-hundred fifty thousand individuals will be diagnosed this year and this cancer will probably be responsible for about 47,900 deaths in 1999 (http://www.cancer.org). Most colon cancers are adenocarcinomas that develop from the glandular cells. Ninety percent of all colon cancer cases will develop in individuals after 50 years of age. Ninety percent of all tumors arise from polyps that are commonly found in people older than 50. Prevention includes regular exercise and a diet high in fiber. The most important risk factor is age. Medical screening includes a yearly blood occult test after age 50 and a colonoscopy every 3 years after age 50. Regular screening detects polyps that have become precancerous. If regular screening is not done, the cancer is not detected until blood is found in the...
Colon Cancer is cancer of the colon, or large intestine. Rectal cancer is cancer of the last few inches of the colon. Together, they're often referred to as colorectal cancers. Most cases of colon cancer begin as small, harmless clumps of cells called polyps. Over time some of these abnormal growths may become colon cancers. Polyps may be small and produce few, signs of sickness. Because of this, doctors recommend regular screening tests to help prevent colon cancer.
People can lower their risk of developing colorectal cancer by managing the risk factors that they can control, such as diet and physical activity. It is important to eat plenty of fruits, vegetables, and whole grain foods and to limit intake of high-fat foods. Physical activity is another area that people can control. Even small amounts of exercise on a regular basis can be helpful, at least 30 minutes of physical activity on most days. Also, achieving and maintaining a healthy weight.
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.
The American Cancer Society publishes current advances made in cancer research on their website. Many of the exciting discoveries about how best to treat the disease focus on the genetic aspects associated with certain types of cancer. In addition, treatments aimed at genetic solutions to cancer may be more effective and may cause fewer adverse side effects than traditional cancer treatments (American Can...
Cancer develops when cells in a part of the body begin to grow out of
Cancer is a disease that affects human somatic cells. It causes the cells to divide uncontrollably and form masses known as tumors. There are two different types of cancer tumors. Some tumors are benign and other tumors are malignant. Benign tumors look similar to the tissues that they came from and develop slowly. The tumor remains in the same area that the tumor originated in. Malignant tumors are formed from cells that do not resemble the tissue that they came from. They vary in shape and size. This enables pieces of the tumor to break off and spread to other places in the body. Over the past few decades cancer has become a very prominent disease. There are many different types of cancer and many different causes for the the disease. Most cancers are because of a genetic mutation. The most common type occur when a cell is dividing. Proto-oncogenes, which are alleles in a normal cells, mutate to form oncogenes. These oncogenes cause cancer because they do not allow the cells to self destruct or become epistatic. There have been several research projects which have been testing epistatis.