Age and Colorectal Cancer Risk

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Age is the number one risk factor for colorectal cancer. More than 90% of people diagnosed with the disease are 50 or older and the average age of diagnosis is 64.

By the time colorectal cancer is diagnosed, it has often been growing for several years, first as a non-cancerous polyp and later as cancer. Research indicates that by age 50, one if four people has polyps.

To learn about other causes of colorectal cancer, please read Fifteen Causes of Colon Cancer.


More Information About Colorectal Cancer

In the United States, colorectal cancer kills about 50,000 people a year, and 150,000 people a year are diagnosed with this deadly disease. Colorectal cancer is the second leading cause of cancer death in the United States.

Fortunately, the incidence and death due to colorectal cancer has declined slightly in recent years. Specifically, between 1992 and 1996, the incidence of this disease declined by 2.1 percent. (The incidence of colorectal cancer in China and Japan continues to rise.) Despite decreasing incidence of this disease, please remember that this cancer is deadly, a significant number of people die of this disease, and you must be screened (think colonoscopy) for this disease if you're aged 50 or older.

In addition to decreased incidence of this disease among Americans and other Westerners, another bit of good news concerning colorectal cancer is that the treatment for advanced disease (Stage III or Stage IV colorectal cancer) has improved.

Furthermore, we now have agents that are more specifically targeted to treat this disease.

Interestingly, when a person migrates from a country with a lower incidence of colorectal cancer (think South America) to a country with a higher incidence of colorectal cancer (think the United States), this person assumes the risk of colorectal cancer of her new home.

In other words, environment in addition to genetics plays a significant role in the development of colorectal cancer.

In addition to age, here are some specific risk factors predisposing a person to the development of colorectal cancer:

  • obesity
  • adenomatous polyps
  • inflammatory bowel disease (Crohn's disease or ulcerative colitis)
  • familial syndromes (think familial adenomatous polyposis)

Although no one can turn back the hand of time and become younger, there are other ways that you can cut your risk of developing deadly colorectal cancer. For example some research shows that ingestion of calcium, vitamin D, folate, or multivitamins may reduce your risk of developing this disease. However, the best way to prevent full-blown colorectal cancer is early detection using colonoscopy, flexible sigmoidoscopy or so forth. If your physician does find a suspicious polyp or lesion on exam, this mass should be removed. If you're more than 50 years old and have yet to receive a colonoscopy or other screening test, it's imperative that you make an appointment with your physician and get screened.


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  4. Detailed Guide: Colon and Rectum Cancer: What Are the Risk Factors for Colorectal Cancer? American Cancer Society. 7 Mar. 2006. 23 Jun. 2006 [].
  5. Overview: Colon and Rectum Cancer: What Causes Colorectal Cancer? American Cancer Society. 15 Mar. 2006. 23 Jun. 2006 [].

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