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Colon Cancer Risk Factors
The lifetime risk of developing colon cancer in the United States is about 7%. Certain factors increase a
person's risk of developing the disease. These include:
Age
The risk of developing Colon Cancer increases with age. Most cases occur in the 60s and 70s, while
cases before age 50 are uncommon unless a family history of early colon cancer is present. Polyps of the colon,
particularly adenomatous polyps, are a risk factor for colon cancer. The removal of colon polyps at the time
of colonoscopy reduces the subsequent risk of colon cancer.
History of cancer.
Individuals who have previously been diagnosed and treated for Colon Cancer are at risk for developing colon
cancer in the future. Women who have had cancer of the ovary, uterus, or breast are at higher risk of developing
colorectal cancer.
Heredity:
Family history of Colon Cancer, especially in a close relative before the age of 55 or multiple relatives
Familial adenomatous polyposis (FAP) carries a near 100% risk of developing colorectal cancer by the age of
40 if untreated Hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome Long-standing ulcerative
colitis or Crohn's disease of the colon, approximately 30% after 25 years if the entire colon is involved.
Smoking.
Smokers are more likely to die of colorectal cancer than non-smokers. An ACS study found that "Women who
smoked were more than 40% more likely to die from colorectal cancer than women who never had smoked. Male
smokers had more than a 30% increase in risk of dying from the disease compared to men who never had smoked."
Diet.
Studies show that a diet high in red meat (Chao et al 2005) and low in fresh fruit, vegetables, poultry and
fish increases the risk of colorectal cancer. In June 2005, a study by the European Prospective Investigation
into Cancer and Nutrition suggested that diets high in red and processed meat, as well as those low in fiber,
are associated with an increased risk of Colon Cancer. Individuals who frequently ate fish showed a
decreased risk. However, other studies have cast doubt on the claim that diets high in fiber decrease the risk
of colorectal cancer. The nature of the relationship between dietary fiber and risk of Colon Cancer remains
controversial.
Physical inactivity.
People who are physically active are at lower risk of developing colorectal cancer.
Virus. Exposure to some viruses (such as particular strains of human papilloma virus) may be associated with
colorectal cancer.
Alcohol. "Heavy alcohol use may also increase the risk of Colon Cancer"