The Colorectal Cancer Screening Guidelines Mess

Before we close out colon cancer awareness month, I want to draw attention to another important paper in the journal Gastroenterology, “Understanding differences in the guidelines for colorectal cancer screening,” by Thomas Imperiale and David Ransohoff. (subscription required, published online March 16 ahead of print).

The authors start with the broad message that guideline-setting in general is of such concern that the Institute of Medicine has formed a committee “to develop standards (that) ensure that clinical practice guidelines are unbiased, scientifically valid and trustworthy.” They remind readers that:

“The problem of varying quality is highlighted by the fact that there are nearly 300 guidelines-making organizations that have created over 2300 guidelines in a process described as “essentially unregulated.”

But their focus was on colorectal cancer screening guidelines, and specifically different updates issued by two major guidelines organizations in 2008:

• The “multi-society” guidelines issued jointly by subspecialists in cancer prevention, gastroenterology and radiology.

• The US Preventive Services Task Force.

The authors focus on the first group’s “preference for tests that image the colon” – especially colonoscopy.

The authors say that the USPSTF, on the other hand, “considered several strategies to be similar in terms of years of life saved and reduction in colorectal-specific mortality,” including colonoscopy and less expensive blood stool tests. The USPSTF stated no preference among methods. But the USPSTF did not share the multi-society group’s endorsement of newer virtual colonoscopy and fecal DNA testing.

These are significant differences, according to the authors:

“The current differences in CRC screening guidelines raise practical questions not only about what doctors and patients should do in the face of disagreement, but also about the larger process by which guidelines are made and how “trustworthy” they may be.

Further, the potential for conflict of interest is real when subspecialists support or recommend procedures from which they derive income is real; that conflict should be acknowledged and managed rigorously. Conflict may be not only financial; it may also be intellectual, when professional enthusiasm causes one to favor what one has learned to do and knows best.”

I encourage journalists to find and read the full Imperiale/Ransohoff paper.

Gastroenterology. 2010 Mar 16. [Epub ahead of print]
Understanding differences in the guidelines for colorectal cancer

Imperiale TF, Ransohoff DF.

Division of Gastroenterology and Hepatology, Department of Medicine,
Indiana University School of Medicine, Indianapolis, IN; Regenstrief
Institute, Inc., Indianapolis, IN.

PMID: 20302867 [PubMed – as supplied by publisher]

And I encourage them to be aware of the Institute of Medicine’s review of guideline setting. Many “awareness month” campaigns are far too simplistic and incomplete and may, indeed, mislead consumers in the certainty they seem to convey. This is far from a certain field at this point in time.

Here are some recent posts raising important questions about what we know and don’t know about colon cancer screening:

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March 27, 2010 at 1:00 pm

I think the underlying questions the authors raise are legitimate. The multi-society panel must be transparent and inclusive of methodologists and generalists in the process and separate the two primary processes: (i) compiling & synthesizing evidence; (ii)the guidelines development process.
The USPSTF might be considered the “gold” standard in evaluating and grading evidence ; however, there are instances where one could suspect the USPSTF might not always be immune to political pressures from DHS, Congress, VA, White House etc.). Given the recent controversy around the mammography guidelines– I suspect there will be major changes…

Greg Pawelski

March 28, 2010 at 10:56 am

Sometimes I question an occasional guideline message on the basis of profit conflicts. Specialty medical societies work to insure their specialist members get reimbursement for common procedures/treatments, the drug industry works to produce evidence statements that promote use of their drugs.
I am not comfortable that many of these trials are objective and balanced. How long would a company pay researchers who continued to disappoint with poor drug or device (efficacy) trial results? And we all know that poor outcomes in these trials are often not reported to the FDA or the public.
National Comprehensive Cancer Network’s (NCCN) main mission is to steer pharmaceutical industry cancer drug clinical trials to their 21 member cancer centers. This equates to steering this funding away from smaller less powerful clinical trials.
The entire premise upon which NCCN bases its evidence-based cancer guidelines may be biased towards maintaining flow of their life blook-industry funded clinical trial dollars. NCCN states clearly on each guideline that NCCN’s guideline policy promotes the concept that all patients be entered into clinical trials.
While on the surface, with many cancers untreatable and terminal, this policy sounds logical – try all therapies and/or combinations, because most cancer patients are going to die anyhow. You have to have the strange feeling about the motives, monopoly of trials and objectives of this, or any other organization.


May 10, 2010 at 9:46 am

Colon cancer has devastated my family; I have the FAP gene but resisted colonoscopy until my doc introduced me to a young GI doc who has done thousands of colonoscopies. She told me of every possible way to get screened and none are anywhere as reliable as optical (regular) colonoscopy. I jokingly said: “easy for you to say, your not getting one” and she smiled and said: “I’m getting one next week, want to watch”? I almost fainted; she was serious and said that I could join a group of med students if I wanted to do so….She also reminded me that during a colonoscopy all eyes are on the screen looking for polyps, not on your butt….I told her o.k. just schedule my exam; I prefered to do it without sedation (not bad, but don’t do this unless you are highly motivated). Prep was a nuisance, exam was not bad and I had a lot of polyps and will be getting yearly exams.

Gary Schwitzer

May 12, 2010 at 4:05 pm

Because of your genetic predisposition, you were at higher risk. We shouldn’t call it screening when we’re looking at people of higher risk.
Screening is a term that applies to looking at a football stadium full of apparently healthy people about whom you know nothing – and then testing to see what you find.
That’s an entirely different set of circumstances for population-wide public health recommendations.
Gary Schwitzer