You may have read or heard about a recent European study calling into question whether colonoscopies were useful in preventing deaths by screening for – and identifying – colon cancer or pre-cancerous polyps, thereby preventing mortality. I even recently wrote a blog post on the topic. So, does colon cancer screening really save lives?

Well, as one might expect, those affiliated with the world of providing colonoscopies in the United States have fired back. American-based medical societies, including the American Society for Gastrointestinal Endoscopy and the American Cancer Society, argue the study is flawed in numerous ways, including the study’s main conclusion that colonoscopies are of questionable benefit.

This includes:

A flawed interpretation of the data – critics of the study note that many participants of the study actually did not get the procedure. How do you know how effective a screening tool is if they didn’t use it? For those who did use it, there was a not insignificant reduction in risk – 31%

Much longer follow up to understand mortality is needed – it can take a long time for polyps to turn into active cancer, often much longer than has been allowed for some of the participants of the study. This includes people who were screened as recently as 8 years ago. Without more time passing, it’s hard to get an accurate picture of how much cancer was prevented and how many lives were saved.

Methods used to perform colonoscopies have improved since the study which have increased the detection rate – simply put, physicians performing colonoscopies have gotten much better at detecting polyps than even 10 or 15 years ago, when this study was performed. Equipment is better, and preparation methods (for those of you who have gone through this procedure, you know what I am talking about) have also improved. All that adds up to better detection rates now than when the study was conducted.

Finally, and perhaps most likely to rankle the colonoscopy doctors in Europe, critics point out that colonoscopies there are less common than in the US. 30% of those physicians involved in the European study did not meet the rate of detection for possibly pre-cancerous polyps. That is, 30% of the doctors may have been missing these adenomas that US doctors would have caught. Simply put, the results of the study do not apply to American patients because our doctors are better.

The pushback against the original study results, coupled with the significant interests by the relevant medical societies, hospitals, medical device manufacturers and physicians who perform colonoscopies (and thereby derive their livelihood from the procedure), make it highly unlikely the standard of care will change with regard to this screening tool anytime in the near future.

However, it does seem to me that such studies, in general, are useful in testing our commonly held beliefs (colonoscopies save lives) in the setting of ever-changing equipment, techniques, and even patient populations. It is good, then, that the medical community is engaging in this sort of rigorous intellectual inquiry instead of falling into complacency. That, I believe, makes us all better informed and generally safer.

You can read an article on this pushback here.