Factors that increase risk
- Old Age. As we age, our DNA breaks down and there is a greater chance for damage to our genes. This damage can lead to cancer.
- Colorectal Adenomas. These are growths called “polyps” that stick out from the lining of the colon. They usually do not produce symptoms, but can sometimes cause bleeding that is not visible to the naked eye. Some polyps can turn into cancer. The polyps that turn into cancer are called “adenomatous polyps” or colorectal adenomas.
- Personal history of colorectal cancer. Having had colorectal cancer may increase your risk for developing colorectal cancer again.
- Personal history of inflammatory bowel disease. Having Crohn's disease or Ulcerative Colitis increases your risk for colorectal cancer.
- Family history of colorectal cancer, other gastrointestinal cancers and uterine or ovarian cancer may increase the risk of colorectal cancer
- Obesity. Having a body weight more than 20 percent of your ideal weight – approximately 20 to 30 pounds – has been linked to colon and rectal cancer.
- Lack of exercise may also increase the risk of colorectal cancer.
- Smoking. Smoking cigarettes is linked to an increased risk of colorectal adenomas, or noncancerous polyps and colorectal cancer. Smokers also have a higher risk for adenomas to come back after they have been removed.
- Alcohol. Drinking alcoholic beverages may increase the risk of colorectal cancer.
- Diet. Studies suggest that diets high in fat, especially animal fat, and low in fiber, calcium and folate may increase the risk of colorectal cancer.
Factors that decrease risk
Regular exercise and a healthy diet may be protective factors.
Inherited colorectal cancer clues
The clues for an inherited risk of colorectal cancer are:
- Colorectal cancer at an early age (before age 50).
- An individual with two or more colorectal cancers, or more than 10 adenomas, which are polyps that may become cancer.
- Individuals who have more than one Lynch-related cancers. Lynch-related cancers include colorectal, endometrial, ovarian, small bowel, stomach, urinary tract, liver, gall bladder ducts, pancreas, and brain tumors.
- Individuals with two or more Lynch-related cancers in the family, especially if one was diagnosed before age 50.
- Sometimes a pathology report shows clues that suggest a hereditary pattern. A pathology report describing the tissue sample or cancer removed after surgery. In the case of cancer, the pathology report describes the size of the tumor, where it was found and important information about the cells.