Is Cologuard as Good as Colonoscopy?

I am regularly solicited for my opinion on the stool test Cologuard, a colon cancer screening option.  These queries generally come from folks who are angling to avoid the joy of the colonoscopy experience.  It’s hard to fathom why someone would want to avoid the pleasure of a supersized laxative followed by a day of fun on colonoscopy day! 

Scientific investigators are working hard on colon cancer screening blood test options, but as I have pointed out, these are not quite ready for prime time.

Finding alternatives to screening colonoscopy is a very high priority for the medical profession. There are two driving forces.

Colonoscopy, while effective, is a laborious process which is a 2-day experience, requires a driver, frequent time away from work, is expensive and has risk.  If a stool or a blood test could achieve the same level of protection, it would be a game changer.

The economic rewards for launching an effective stool or a blood colon cancer screening test would be astronomical.

While we’re not there yet, I am confident that medical technology will triumph and colonoscopy will be relegated to a much lower tier or might be left off the screening list entirely.  Of course, we will still need skilled colonoscopists in the event the stool or blood screening test is positive.  Ironically, during that era, gastroenterologists will be doing just a small fraction of colonoscopies compared to current practice and they may have less procedural skills because of this.  It is axiomatic that physician proceduralists maintain a high skill level by performing a high volume of procedures.  You’d rather have a cardiac catheterization performed by a doctor who does one or two cases per day rather than one or two cases per month.  Same argument for colonoscopies

Willing to roll the dice on Cologuard?

Once non-invasive screening tests take over, there won’t be routine screening colonoscopies, which constitutes the bulk of my procedure volume now.  Colonoscopies will be done only if non-invasive screening tests are positive.  What will likely occur is that only a minority of gastroenterologists will do these colonoscopies to that they will be able to maintain a high procedure volume for the reasons state above.

I tell patients today that Cologuard has the advantages of simplicity and convenience.  But it can’t rival colonoscopy in terms of protecting against colon cancer.  So patients have to decide which path to take based on their priorities.   The choice is either ease or effectiveness.