Tuesday, April 19, 2011

D. Colorectal cancer

Colorectal cancers is the second most common of the visceral cancer and defined as cancers in the digestive system that inlvove part of the large intestine (colon) and the last several inches of the colon. It strarts as a benign noncancerous adenomatous polyps. As ot progress through its stages, it can be cancerous.
1. Symptoms
The symptoms are always seen in abnormal bowel habits as changing in the consistency of stool for more than a couple of weeks as well as bleeding and blod in the stool.
2. Risk factors
a. Heredity
Heredity although is not common, but you are high risk to have colorectal cancer if your parent or your sibling had it.
b. Overweight
Study showed that people who are 40% overweight above the average have a 35% high risk to develop colorectal cancer.
c. Aging
Colorectal cancer increases the risk with age of over 50. It may be caused by declining function of digestive system in digestive food properly that put pressure to the large intestine.
d. Gender
Would it be true that men are likely to develop colorectal cancer than women?
e. Diet
Diets high in saturated and trans fat have been found to cause colon cancer due to low amount of fiber which sre important in assisting the digestive system in waste removal.
f. Etc.

3. Free radical and colorectal cancer
Study showed normally cells stop in the cell division or replication cycles if DNA is damaged but if P53 protein is defective in many different types of cancer as a result of cells do not stop dividing when DNA is damaged, leading to genomic instability. Enterococcus faecalis is commensal bacterium inhabiting the gastrointestinal tracts produced extracellular superoxide and hydrogen peroxide free radical in some people. As the free radicals react to molecules, it cause alternation of colonic DNA and if the production become chronic, it may leading to cancers.

2. Antioxidant and colorectal cancer
a. Vitamin E
Study found that using the conbination of vitamin E and pyrrolidinedithiocarbamate can stop the colorectal cancer cells by bringing in a chemical arrest the cancer cell activity.
b. Beta carotene
Study showed that beta carotene plays an impotant role to protect aginst normal crypt foci, behnin and allignant tumors of rat in high fat and variable fiber diet.
c. Salicylic acid
Salicylic acid in fruit and vegetable can inhibit the risk of colorectal cancers.
d. Grape seed extract
Reseracher fond that antioxidant, proanthocyanidins found in grape seeds significantly inhibits growth of colorectal tumors in both cell cultures and in mice.
e. Etc.