Cologuard or Colonoscopy?

Many patients are aware of Cologuard as a colon cancer prevention option.  The appeal is obvious. One can submit a Cologuard stool test and forego the joys of colonoscopy.  Indeed, what motivates patients to select the easier option is not belief in the product but an opportunity to avoid a much less pleasant alternative.  This is analogous to how many of us vote in elections.  Rather than vote for a candidate we are often voting against another candidate.

                                      

Did you vote for or against a candidate?

Cologuard is much more sophisticated and expensive than the conventional stool testing for occult blood which has been standard fare for decades.  Cologuard will also detect microscopic blood in the stool but will also pick up abnormal DNA which could indicate the presence of a large precancerous polyp or even a cancer.  Hence, when a Cologuard test is positive, a subsequent colonoscopy is mandatory.  However, many positive Cologuard results are false positive results as the follow up colonoscopy is normal.  This is always greeted by relief by patients and the medical staff.

While Cologuard is convenient, it is clearly inferior to colonoscopy with regard to reducing colon cancer risk.  This is a fact.  However, the colonoscopy experience has many drawbacks as tens of millions of patients can attest.  Let’s break the process down.

A colonoscopy is ordered.

The patient is tasked to drink a large volume of a solution which yields a volcanic result. Many patients describe the cleansing process as horrendous.

Prep ingestion can result in dehydration particularly in elderly individuals.

Prep ingestion can alter electrolytes which rarely can have medical consequences.

The patient may need to miss at least a day of work.

A driver is necessary.

Anesthesia and the procedure have medical risks which are very low but > zero.

Even an expertly performed colonoscopy on a clean colon is not 100% accurate.

There is a recovery period with restrictions after the procedure.

I’ve performed tens of thousands of colonoscopies over the past few decades.  Indeed, I’ve also been on the receiving end of the scope and look forward to my next experience.  I believe in the procedure. But the inconvenience, risks, time required, joy of prep guzzling and missing work are substantial downsides to endure.  Hence, the appeal of Cologuard, an inferior medical option.  

Routine screening colonoscopy is going to disappear and may occur sooner than we think.  I expect that highly accurate non-invasive colon cancer screening tests using stool, blood or saliva will emerge which will be game changers.   Cologuard, while imperfect, heralds coming attractions.