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Weekend doctor: Cologuard Test

New colon cancer screening

By Jay Alammar, MD
Surgical Associates of Northwest Ohio
Colorectal cancer is a common disease, and colon cancer screening continues to be of utmost importance. Preventing cancer or detecting and removing it early when it is still localized greatly impacts colon cancer related mortality.

Several screening tests are currently available in our armamentarium to aid in the detection of precancerous polyps and early detection of colon cancers. Each of the available tests has its pros and cons in regard to sensitivity, effectiveness, convenience, cost, frequency, degree of invasiveness and associated risks. Screening colonoscopy is considered by many experts in the field to be the gold standard due to its greatest impact on prevention and early detection of colorectal cancer. Colonoscopy detects about 95 percent of lesions greater than 6 mm.

A new test called Cologuard was approved by the FDA in 2014 for patient's between ages 50 and 85. The test is appealing because it is noninvasive, completed at home, requires no prep or sedation, and is covered by Medicare. With the Cologuard test, a stool sample is obtained, packaged and shipped to the company using the provided kit. The results are usually reported to the ordering physician in a couple weeks.

Other facts about Cologuard Testing include the following:

  • The test detects 92 percent of colon cancers.
  • The test rules out cancer in 87 percent of cases.
  • The test only identifies 42 percent of precancerous polyps.
  • The test specificity decreases when the patient’s age increases.
  • The test does not diagnose cancer or polyps. Positive tests require the patient to have a colonoscopy to make a diagnosis.
  • The test should be repeated every three years.
  • The test should not be used in patients with history of colon cancer or colon polyps, family history of colon cancer, personal history of ulcerative colitis, Crohn's disease, or symptomatic hemorrhoids.
  • The test should not be used in patients with anemia or those who have gastrointestinal symptoms such as a change in bowel habits.

The Cologuard test will likely assist in the fight against colon cancer when used in the appropriate setting. It is another weapon added to our colon cancer screening arsenal. The test is not intended to replace colonoscopy, but it is considered a second-tier option for the patient that refuses a colonoscopy. Considering the above facts, colonoscopy will continue to be the best screening modality.

Talk to your health care provider about colon cancer screening and the best option for you.