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Screening Tests for Adults (Ages 30-49)

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Not everyone in this age group may need screening for every condition listed here. Click on the links above to read more about each condition and to determine if screening may be appropriate for you or your family member. You should discuss screening options with your health care practitioner.

Colorectal Cancer

Colorectal cancer is the third most common non-skin cancer in adults and the second leading cause of cancer deaths in men and women in the United States. Cancer of the colon and rectum is both preventable and treatable if detected early. Studies show that regular screening could prevent one-third of colorectal cancer deaths in the U.S. The five-year survival rate is 90% if detected early.

Screening tests that look for and remove polyps and lesions in the colon can prevent colorectal cancer. These are found most often in people 50 years of age and older, so experts do not recommend universal screening of average risk people until the age of 50. However, if you have one or more risk factors for colon cancer, described below, you should talk to your healthcare provider. He or she can help you assess your individual risk factors and determine if you should begin screening before age 50 and what tests are appropriate based on your risks. As the Centers for Disease Control and Prevention (CDC) notes, any of the recommended tests is better than no test.


Earlier, more frequent screening is appropriate at a younger age, often beginning at age 40, if you have certain risk factors and fall into the categories for increased or high risk. Screening can begin even earlier in some cases.

  • Increased risk:
    • If you have a family history of colorectal cancer or adenomatous polyps, a specific type of polyp associated with higher risk of colorectal cancer, you are at increased risk and may need earlier screening. Most of these cancers occur in people without a family history of colorectal cancer. Still, as many as 1 in 5 people who develop colorectal cancer have other family members who have been affected by this disease.

      Specifically, if you have a first-degree relative (parents, siblings or children) who had colorectal cancer or adenomatous polyps before age 60, or two or more first-degree relatives who had either of these findings at any age, you have increased risk for colorectal cancer. The risk is about doubled in those with one affected first-degree relative. It is even higher if the first-degree relative is diagnosed at a young age, or if more than one first-degree relative is affected.

    • You may also be at increased risk for colorectal cancer if you have been diagnosed with colon cancer in the past or if you have had a history of polyps on a prior colonoscopy.
    • Race and ethnicity can increase risk. African Americans have the highest incidence of colorectal cancer and Ashkenazi Jews have the highest risk of developing colorectal cancer.
  • High risk: You are at high risk for colorectal cancer if you have inflammatory bowel disease, including chronic ulcerative colitis or Crohns disease. If you have a genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (HNPCC), or if you are at an increased risk of HNPCC based on your family history, you are also in the high-risk category.

Types of Tests Used for Screening

  • A colonoscopy is usually recommended for people who are at intermediate or high risk of colorectal cancer and require screening before the age of 50. The procedure uses a probing scope and a video camera to view the entire length of the colon. This allows any polyps or other suspicious tissue to be removed and tested for the presence of cancer. Though the most costly and invasive, colonoscopy is the most accurate and thorough test and is especially appropriate for those with risk factors.

Other types of screening tests may be options for people who are considered to be similar to those of average risk. This may include, for example, people with a first degree relative who had colon cancer after the age of 60.

Some of these testing options include laboratory tests performed on stool samples that mainly detect existing cancers:

If the findings on one of these are abnormal, you will need a colonoscopy.

Besides colonoscopy, other imaging procedures may be used for screening.

  • Flexible sigmoidoscopy is similar to colonoscopy in that it uses use a probing scope and a video camera, but it uses a shorter probe that views the entire rectum and only the lower third of the colon. This approach is also able to remove any polyps that are found and allows for them to be tested for the presence of cancer cells.
  • Two other procedures use X-rays; however, these approaches only allow visualization of polyps. Removal of the polyps would require a follow-up colonoscopy or flexible sigmoidoscopy:
    • Virtual colonoscopy (computed tomography (CT) colonograph) combines many cross-sectional images into 2-D and 3-D views of the colon. This procedure is less invasive and does not require sedation, thus may be appropriate for those who cannot tolerate a colonoscopy.
    • Double-contrast barium enema (DCBE), also known as air-contrast barium enema or lower GI series, provides X-ray views of lumps, polyps, and/or other abnormalities in the outline of the colon.

Stool sample testing and sigmoidoscopy are easier than colonoscopy but not as accurate. Stool testing and sigmoidoscopy are best used in conjunction with each other.


Several health organizations have colon cancer screening recommendations. While they may differ on which tests to use and how often, they each support screening for colon cancer. In March 2008, screening guidelines for the early detection of pre-cancerous polyps and colon cancer were released jointly by the American Cancer Society, the U.S. Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. Similar guidelines have also been proposed by the U.S. Preventive Services Task Force (USPSTF) and the American College of Gastroenterology. These comprehensive screening guidelines include people who are at increased risk for colorectal cancer, thus candidates for screening before age 50. If you are at increased or high risk for colorectal cancer, your healthcare provider can help you assess the best combination(s) of preventive tests and how frequently you should have them.

The guidelines suggest:

  • If you have a family history of colorectal cancer or adenomatous polyps in any first-degree relative diagnosed before the age of 60, or in at least two second-degree relatives at any age, they recommend screening to begin at age 40 or 10 years before the youngest case in the immediate family; if after the age of 60, then options are the same as those offered to someone of average risk.
  • Inflammatory bowel disease: the guidelines recommend that screening begin 8 years after the onset of the disease.
  • Hereditary non-polyposis colon cancer (HNPCC): the guidelines recommend that screening begin when you are 20 to 25 years old, or 10 years before the youngest case in the immediate family.
  • Familial adenomatous polyposis (FAP) diagnosed by genetic testing, or suspected FAP without genetic testing: ACS recommends that screening begin at 10 to 12 years of age.
  • People of African descent should begin testing at age 45. However, the USPSTF states that its recommendations for average risk individuals are intended to apply to all ethnic and racial groups.

Decision Aids

Because any invasive procedure carries some level of risk, you should talk to your healthcare provider about the screening tests recommended for you. Some employers, health plans, and health practitioners offer decision aids.

Also, don't neglect the protection of getting re-tested at the interval recommended by your healthcare provider.

Links Colon, Adenomatous polyps
National Cancer Institute: Colorectal Cancer Risk Assessment Tool
Centers for Disease Control and Prevention: Colorectal (Colon) Cancer

Sources Used in Current Review

American Cancer Society recommendations for colorectal cancer early detection. American Cancer Society. Available online through Accessed February 2015.

Final Recommendation Statement Colorectal Cancer Screening. U.S. Preventive Services Task Force. Available online at through Accessed February 2015.

Tests to Detect Colorectal Cancer and Polyps. National Cancer Institute. Available online at through Accessed February 2015.

(February 26, 2014) Centers for Disease Control and Prevention. Colorectal (Colon) Cancer: What are the Risk Factors? Available online at through Accessed January 2015.

(Published online 2008 February 13). Screening and Surveillance for the Early Detection of Colorectal Cancer and Adenomatous Polyps, 2008: A Joint Guideline From the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. American Gastroenterology Association [On-line information]. Available online at through Accessed February 2015.