Personal Screening Strategy
Based on your personal risk factors for colorectal cancer, you will want to develop a personal screening strategy with your doctor to decide when to begin screening, how often to repeat it, and what method to use.
Consider your age, personal medical history, family history, lifestyle factors, and ethnic background in developing your plan.
Age
All men and women over the age of 50 are at least of average risk for colon and rectal cancer and should begin a screening program using one of the approved methods when they reach 50.
More than ninety percent of colorectal cancer occurs after the age of 50. Risk increases with each decade of life.
While the average age for a diagnosis of colon cancer is 70, both men and women can get colorectal cancer at any age, so symptoms of colorectal cancer should be always be evaluated with colonoscopy even if the person is younger than 50. No one is “too young” for colorectal cancer.
Personal medical history
Inflammatory bowel disease
Patients with ulcerative colitis or Crohn’s Disease are about five times more likely than someone without inflammatory bowel disease to have colorectal cancer. However, the Colitis and Crohn’s Foundation points out that 90 percent of patients will not develop colon or rectal cancer.
Risk increases with the length of time the disease been active and with the length of colon involved.
Beginning about 8 years after diagnosis, patients should have annual colonoscopies with biopsies. If you have inflammatory bowel disease, work with your gastroenterologist to develop a surveillance schedule for your individual needs.
Irritable bowel syndrome (IBD) doesn’t seem to be associated with an increased risk for colorectal cancer, so patients with IBD can follow screening recommendations for average risk people.
Adenomatous polyps
After a clearing colonoscopy to remove all polyps, follow-up colonoscopies are recommended at 3 years for high-risk polyps or 5 years for lower-risk ones. Normal colonoscopies can be followed up in 10 years.
Diabetes
An analysis of studies that looked at risk for colorectal cancer in people with diabetes found that diabetics have about a 30 percent increased risk of colorectal cancer.
No guidelines exist for screening people with diabetes beyond that for people of average risk. However, obesity and lack of exercise are associated with both colorectal cancer and diabetes. Diabetics should probably be extra vigilant staying up-to-date with screening and try to control their weight and increase their exercise.
Family history
Familial Risk
People with one first-degree relative with colorectal cancer diagnosed under the age of 60 or two or more first degree relatives with colorectal cancer at any age are at increased risk for colorectal cancer. A first-degree relative is a parent, brother or sister, or a child.
People with familial risk should begin screening with colonoscopy at age 40 or 10 years before the earliest diagnosis in their family, whichever is sooner. If normal, colonoscopy should be repeated every 5 years.
Remember that more than 80 percent of colorectal cancer happens to people with no family history. Just because colorectal cancer doesn’t run in your family does not mean you are not at risk for it.
Lynch Syndrome: Hereditary Non-Polyposis Colon Cancer
Lynch Syndrome or HNPCC is an inherited condition that puts people at very high risk for colon cancer, as well as several associated cancers. It is caused by a mutation in one of the genes that repairs damaged DNA. Without that repair, damaged cells can develop into cancer. HNPCC is directly passed down from parent to child ( autosomal dominant ).
Because HNPCC cancers develop much more rapidly and at a younger age than sporadic colorectal cancers, it is important to begin colonoscopy surveillance earlier and do it more frequently. Guidelines call for beginning colonoscopis at age 20 to 25 and repeating them every 1 to 2 years.
Women with HNPCC are at greatly increased risk for endometrial cancer (cancer of the uterine lining). Their lifetime risk is somewhere between 40 and 60 percent. Annual uterine biopsies are recommended for them beginning at age 30 to 35. They also have about a 10 to 12 percent lifetime risk of ovarian cancer and should discuss a strategy for ovarian cancer screening with their gynecologists.
Familial Adenomatous Polyposis
FAP is an inherited gastrointestinal cancer syndrome where literally hundreds of polyps carpet the colon and sometimes the upper GI tract. It can be seen in children but most often appears in early adolescence. Autosomal dominant, it is passed down directly from parent to child. Untreated the high risk of developing colon cancer during a person’s lifetime is 100 percent. Average age for FAP cancer to appear is 39.
Genetic testing at age 10 to 12 can identify children who will develop FAP. Annual surveillance with sigmoidoscopy and genetic counseling to decide on how best to manage the disease should begin with adolescenc
Lifestyle Factors
Although there are no special screening recommendations beyond those for people of average risk, there are factors associated with lifestyle choices that increase risk for colorectal cancer. Patients with these risks should be especially vigilant in maintaining their screening strategy. Changing diet or behavior may also decrease risk. Factors that have been associated with increased risk for adenomas and colorectal cancer include:
- Smoking
- Obesity
- Heavy alcohol use
- Lack of exercise
- Diets rich in red meat and processed meat
- Diets low in fruits and vegetables
- Little sunshine or vitamin D in the diet.
However, a healthy lifestyle cannot protect you completely from colorectal cancer. Your best protection is always screening.
Ethnic background
African-Americans
African Americans have an increased risk for colorectal cancer and a higher risk of dying from it. Some studies show they also are diagnosed at a younger age and are more likely to have polyps and cancers in the right side of their colons. As a result the American College of Gastroenterology recommends that screening for African Americans begin at age 45.
Jews of Eastern European descent, have the highest risk of colorectal cancer in the world. Several genetic mutations have been found associated with colorectal cancer in Ashkenazi Jews. One gene — APC I1307K — is carried by 6 percent of Ashkenazi Jews and about one third of Ashkenazi families with a history of colorectal cancer.
People who have tested positive for the gene should begin colonoscopy surveillance at 35, or 5 to 10 years before the earliest family diagnosis of cancer or polyps, and have exams every two years.
Family members should be advised to be tested for the gene, as well.
Where Can You Go for More Information?
Preventing Colorectal Cancer: A Clinician’s Guide provides information and diagrams to help assess the level of risk for colorectal cancer along with methods for screening and surveillance.
Guidelines for Colonoscopy Surveillance after Polypectomy is a consensus developed by the US Multi-Disciplinary Task Force on Colorectal Cancer and the American Cancer Society for how often to repeat colonoscopies when polyps are found.
Colorectal Cancer in the Ashkenazi (Eastern European) Jewish Population is patient information from the Cleveland Clinic describing testing for genetic changes affecting Ashkenazi Jews.
Last Update: October 2, 2008
Medical Review
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