Who is at risk for colorectal cancer? What causes it?

No one knows for sure what causes colorectal cancer. But there are certain risk factors that can increase a person's chances of getting or dying from this type of cancer:

• Ethnicity/Race - People of African-American and Hispanic descent are often diagnosed at a later stage of disease and have a higher death rate.
  
  
• Age - People over the age of 50 tend to get this cancer more often than younger persons do. But, it can happen at any age.
  
  
• Diet - Colorectal cancer appears to be linked to diets high in fat and calories and low in fiber. Researchers are looking at how diet plays a role in colorectal cancer.
  
  
• Polyps - are benign (not cancerous) growths on the inner wall of the colon and rectum. Many people over age 50 have polyps. Some types of polyps, called adenomatous polyps, can become cancers. Between 5 and 10% of adenomatous polyps will become cancer if not removed.
  
  
• A rare form of polyps that runs in families, called familial polyposis, almost always becomes cancer. This condition causes hundreds of polyps to form in the colon and rectum. In these cases, there are treatments that can be done at a young age to prevent cancer from developing.
  
  
• Personal medical history - Women who have had cancer of the ovary, uterus, or breast have a somewhat greater chance of getting colorectal cancer. A person who has had colorectal cancer once can get it again. A person who has had polyps in the colon or rectum is also at increased risk for this cancer.
  
  
• Family medical history - "First-degree" relatives (parents, sisters, brothers, children) of a person who has had colorectal cancer are somewhat more likely to get this type of cancer. The risk is even greater if the relative had the cancer at a young age. Risk is increased even more if many family members have had colorectal cancer. There are genetic tests available for people whose family has a certain pattern of cancer.
  
  
• Inflammatory bowel disease - is a condition in which the lining of the colon becomes inflamed, or irritated. Having this condition increases a person's chances of getting colorectal cancer. The most common kinds of inflammatory bowel disease are Crohn's Disease and ulcerative colitis.
  
  
• Lifestyle - The couch potato lifestyle (no exercise), being overweight (obesity), drinking alcohol, and smoking may increase a person's chances for getting colorectal cancer.
  
  
• Long-term exposure to environmental or occupational toxins (poisons) may increase a person's risk for colorectal cancer.

Having one or more of these risk factors does not mean that you will develop colorectal cancer. It just increases your chances. Talk with your health care provider about what you can do to lower your risk for colorectal cancer.