Scientists don't know exactly what causes colorectal cancer, but they have been able to identify some risk factors for the disease. A risk factor is anything that increases your chances of getting a disease.
Studies show that the following risk factors may increase a person's chances of developing colorectal cancer: age, polyps, personal history, family history, and ulcerative colitis.
Colorectal cancer is more likely to occur as people get older. It is more common in people over the age of 50, but younger people can get it, too. In rare cases, it can occur in adolescence.
Polyps are benign, or non-cancerous, growths on the inner wall of the colon and rectum. They are fairly common in people over age 50. Some types of polyps increase a person's risk of developing colorectal cancer. Not all polyps become cancerous, but nearly all colon cancers start as polyps.
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The link between diet and colorectal cancer is not firmly established.
There is evidence that smoking cigarettes and drinking 3 or more alcoholic beverages daily may be associated with an increased risk of colorectal cancer.
Research shows that women with a history of cancer of the ovary, uterus, or breast have a somewhat increased chance of developing colorectal cancer. Also, a person who has already had colorectal cancer may develop this disease a second time.
The parents, siblings, and children of a person who has had colorectal cancer are somewhat more likely to develop this type of cancer themselves. This is especially true if the relative had the cancer at a young age. If many family members have had colorectal cancer, the chances increase even more.
Ulcerative colitis is a condition in which there is a chronic break in the lining of the colon. Having this condition increases a person's chance of developing colorectal cancer.
Researchers have identified genetic mutations, or abnormalities, that may be linked to the development of colon cancer. They are working to unravel the exact ways these genetic changes occur. Recent results from The Cancer Genome Atlas study of colorectal cancer point to several genes (BRAF and EGRF among others) that may increase risk.
If You Have Risk Factors
If you have one or more of these risk factors, it doesn't mean you will get colorectal cancer. It just increases the chances. You may wish to talk to your doctor about these risk factors. He or she may be able to suggest ways you can reduce your chances of developing colorectal cancer and plan an appropriate schedule for checkups.