Doctors believe that colorectal cancer is not contagious (a
person can not get a disease from a cancer patient). Some people are more
likely to develop colorectal cancer than others. Factors that increase a
person's risk of colorectal cancer include high fat intake, a family history of
colorectal cancer and polyps, the presence of polyps in the colon, and
ulcerative colitis as a chronic (chronic ulcerative colitis).
Diet (Food) and colon cancer
Diets high in fat are believed to affect (the tendency to give) in human
colorectal cancer. In countries with colorectal cancer rates are high, the fat
intake by the population is much higher than in countries with cancer rates are
low. It is believed that the breakdown products of fat metabolism lead to the
formation of chemicals that cause cancer (carcinogens). Diets high vegetables
and foods high in fiber such as bread, whole-grain breads and wheat-wheat can
clean the bowel of these carcinogens and help reduce the risk of cancer.
Colon polyps and colon cancer
Doctors believe that most colon cancers develop in colon polyps. Therefore, removing polyps benign colon can prevent colorectal cancer. Colon polyps develop when chromosome damage occurs in cells in the lining of the colon. Chromosomes contain genetic information inherited from each parent. Normally, healthy chromosomes control the growth of cells in an orderly manner. When chromosomes are damaged, cell growth becomes uncontrolled, resulting in masses of extra tissue (polyps). Colon polyps are initially friendly (is good). Through the years, colon polyps friendly can obtain additional chromosome damage to become cancerous.
Ulcerative colitis and colon cancer
Ulcerative colitis (ulcerative colitis) that causes chronic inflammation of the lining of the colon. Colon cancer is a recognized complication of ulcerative colitis are chronic. The risk begins to rise after eight to 10 years of colitis (colon inflammation). The risk of developing colon cancer in a patient with ulcerative colitis (ulcerative colitis) was also associated with the location and the extent of his illness.
Current estimates of the cumulative incidence of colon cancer associated with ulcerative colitis was 2.5% at 10 years, 7.6% at 30 years, and 10.8% at 50 years. Patients who are at higher risk of cancer are those with a history of colon cancer, a long duration of colitis, extensive colon involvement, and those with primary sclerosing cholangitis (PSC).
Since the cancers associated with ulcerative colitis have a better outcome if caught at an early stage, colon examinations per year are often recommended after eight years of known extensive disease. During these examinations, samples of tissue (biopsies) can be taken to look for changes in the precancerous cells lining of the colon. If precancerous changes in cancer is found, removal of the colon may be necessary to prevent colon cancer.
Genetics of Colon Cancer
A person's genetic background is a risk factor for colon cancer is important. Among first-degree relatives of patients with colon cancer, the lifetime risk of developing colon cancer is 18% (a threefold increase of the general population in America).
Even though family history of colon cancer families is an important risk factor, the majority (80%) of colon cancers occur sporadically in patients who have no family history of colon cancer. Approximately 20% of cancers are associated with a family history of colon cancer. And 5% of cancer-colon cancer syndromes are caused by hereditary colon cancer. Syndromes hereditary colon cancer are disorders where family members are affected have inherited the genetic defects that cause cancer of one or both parents.
Chromosomes contain genetic information, and chromosome defects cause genetic damage that leads to the formation of colon polyps and colon cancer. In polyps and sporadic cancers (polyps and cancers that develop in the absence of family history), the chromosome defects are obtained (grown in a cell during adult life). Broken chromosomes can only be found in the polyps and cancers that develop from that cell. But in syndromes hereditary colon cancer, chromosome defects are inherited at birth and is present in every cell of the body. Patients who have inherited the gene-gene syndrome hereditary colon cancer are at risk of developing large number of colon polyps, usually at young ages, and are at high risk of developing colon cancer in early his life, and also are at risk of developing cancers in other organs.
FAP (familial adenomatous polyposis) syndrome is a hereditary colon cancer in which the members of the affected family will develop countless numbers (hundreds, sometimes thousands) of colon polyps starting during the teens. Unless the condition is detected and treated (treatment involves removal of the colon) early, a person affected by familial polyposis syndrome is almost sure to develop colon cancer from these polyps. These cancers usually develop at the age of forty (40). These patients also are at risk of developing other cancers such as cancers of the thyroid gland, stomach, and the ampulla (the part where the bile ducts drain into the duodenum / duodenum just behind the stomach).
AFAP (attenuated familial adenomatous polyposis) is a lighter version of the FAP. Affected members develop less than 100 colon polyps. Nevertheless, they remain at very high risk of developing colon cancer at young ages. They also have the risk of gastric polyps and duodenal polyps (duodenum).
HNPCC (hereditary nonpolyposis colon cancer) is a hereditary colon cancer syndromes where members of the affected family can develop polyps and colon cancers, usually in the right colon, in the thirties (30) and forty (40) . Certain HNPCC patients are also at risk of developing cancer of the womb (uterine cancer), stomach cancer, ovarian cancer (ovarian cancer), and cancers of the ureters (the tubes that connect the kidneys to the bladder), and biliary tract ( the ducts that drain bile from the liver to the intestines).
MYH polyposis syndrome is a hereditary colon cancer syndrome that lately discovered. Members who are affected typically develop 10-100 polyps occurring at around the age of forty (40), and high-risk developing colon cancer.
