Early Colon Cancer Screening- Give Cologuard a Chance Maybe?

Where rank number one has been occupied by breast cancer in women and prostate cancer in men, colon cancer ranks second in the prevailing cancer incidences… Melisa Silver - April 11, 2016

Where rank number one has been occupied by breast cancer in women and prostate cancer in men, colon cancer ranks second in the prevailing cancer incidences of the present. However, the good part about colorectal cancer facts is that it is easily screened at its early stages, which enables early treatment before the prognosis becomes worse.

The colon is exposed to several highly toxic and injurious substances in the blood and gastric fluids many times a day, which increases its chances of developing cancer by many folds. Moreover, unhealthy bowel habits, genetic factors, and unhealthy lifestyle habits make one more prone toward getting a cancerous colon.

The most common type of colorectal cancer is ‘adenocarcinoma‘. It may arise in the beginning as a polyp or a tumor. When a polyp is allowed to stay in the colon for years, it may develop into cancer. Hence, early detection and excision of these polyps is a useful preventive measure.

Talking about early screening and detection of the disease, there is a tool called ‘Cologuard’, which can perform the task. The device makes use of advanced stool DNA technology. The theory related with Cologuard is that, colon shreds many of its cells in the stool. By applying advanced DNA techniques, abnormal contents of the colon cells, specially the DNA can be detected from the stool. This is how Cologuard works.

Cologuard is not a replacement for other medically devised methods of colon cancer screening. It is in fact indicated to individuals who:

  • have colon polyps or cancer
  • have a positive family history for the disease
  • had positive results in another such screening test within the last 6 months
  • are at a high-risk of getting the disease: for example, presence of gut conditions such as Crohn’s disease, Familial adenomatous polyposis, inflammatory bowel disease, ulcerative colitis etc.

That was all about colon cancer and Cologuard for early screening. But should you really go for this method? What does science say about it? Well lets find out.

The conventional methods for screening that are recommended for colorectal cancer are sigmoidoscopy at an interval of every 5 years, colonoscopy at an interval of 10 years, stool sample tests for detecting occult blood, and a CT scan at every 5 years. The frequency of these screening tests shall increase for those at high risk for the disease.

The American Cancer society allows people to opt for whichever screening method they would want to go for. However, many recommend and consider colonoscopy as the primary tool. It is also known as the ‘gold standard’ screening method for colon cancer. FIT (fecal immune test) is also useful in this regard, since it detects the presence of antibodies in the stool sample.

Cologuard was developed in the year 2014 with the advantage of performance of two tests with a single kit. It looks for occult blood in the stool sample, as well as detects DNA changes in the colon cells, or those of the colon polyps. An entire stool sample of the patient must be provided to the company, which then looks for the evidences. Cologuard requires no medication or dietary restrictions.

For colorectal cancers, the sensitivity of this newly formulated screening tests is observed to be about 92.3 percent in general (which is actually good!), and 94 percent for cancers at their early stages. For high-grade cancers, the sensitivity of Cologuard is 69.2 percent, which is much higher in comparison to the 46.2 percent of fecal immune test (FIT). In only 10 percent of the cases, there is a chance that Cologuard shows ‘false positive results’, which means that the test comes out positive, although there is no abnormality present in the organ.

As compared to the expenses produced by colonoscopy alone (which range from $3500-$6000), Cologuard costs around $649 merely. However the specificity of colonoscopy in detecting colorectal cancers is yet many times higher than Cologuard. Even after the Cologuard test results come out positive, a complete colon scan with colonoscopy is an essential requirement.

So the question that arises here is, why should one go for Cologuard when they still have to undergo colonoscopy if the test comes out positive? Well, the fact is, many of us are bothered with the term ‘invasiveness’. Cologuard is a non-invasive test that protects us from going through invasive techniques unless required. Its high sensitivity in comparison to FIT and stool blood test draws one towards a more accurate result, and somewhat helps in determining whether they should go for a colonoscopy or not.

So the next time you are offered Cologuard screening for detection of the possibility of the disease, give the method a chance.

Reference: A Word from Dr. Pfenninger about colon cancer screening with Cologuard