Colorectal cancer starts in either the colon or the rectum and, in most cases, develops slowly over many years. Most start as a polyp - a growth of tissue that starts in the lining and grows into the center of the colon or rectum. A type of polyp known as an adenoma can become cancer. Over 95 percent of colon and rectal cancers are adenocarcinomas that come from such polyps. Removing a polyp early can stop it from becoming cancer.
According to the most recent U.S. estimates, 2010 will present about 102,900 new cases of colon cancer, 39,670 new cases of rectal cancer and about 51,370 deaths from colorectal cancer. Colorectal cancer is the fourth most common cancer found in men and women in this country. The risk of a man having colorectal cancer in his lifetime is about one in 19. For women it is about one in 20. However, the likelihood of death from colorectal cancer has been steadily decreasing. Thanks to increased and improved screening, polyps can be found and removed before they turn into cancer or when the cancer is still in its early stages when it is easier to cure.
|Causes and Risk Factors|
|Age: The chances of having colorectal cancer go up after age 50. More than nine out of ten people with colorectal cancer are older than 50|
|Having had polyps or colorectal cancer before: Some polyps increase the risk of colorectal cancer, especially if they are large or if there are many of them. Previous instances of colorectal cancer (even if completely removed) make new cancers more likely to occur in other areas of your colon and rectum. These chances increase if you had your first instance at a relatively young age|
|History of bowel disease: Inflammatory bowel diseases, like ulcerative colitis and Crohn's disease, increase the risk of colon cancer. Irritable bowel syndrome (IBS), is different from inflammatory bowel disease, and does not increase colorectal cancer risk|
|Family history of colorectal cancer: If you have close relatives with this cancer, your risk might be increased - especially if the family member got the cancer at a relatively young age|
|Race or ethnic background: Some racial and ethnic groups such as African Americans and Jews of Eastern European descent have a higher colorectal cancer risk. Among Ashkenazi Jews, several gene mutations have been found that lead to an increased risk of colorectal cancer|
|Certain types of diets: A diet high in red meats and processed meats can increase your colorectal cancer risk. Cooking meats at high heat (frying, broiling, or grilling) generates chemicals that might increase cancer risk. Diets high in vegetables and fruits have been shown to lower risk of colorectal cancer|
|Lack of exercise: Exercise may help reduce your risk|
|Overweight: Maintaining a healthy weight decreases a person's risk of having and dying from colorectal cancer|
|Smoking: Long-time smokers are more likely to have and die from colorectal cancer|
|Alcohol: Heavy alcohol use has been linked to colorectal cancer|
|Diabetes: People with Type 2 diabetes have an increased chance of getting colorectal cancer. They also tend to have poorer outcomes||