New Task Force Guideline Recommends Three Tiers of CRC Screening

David A. Johnson, MD


July 07, 2017

Hello. I am Dr David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia.

In July, the US Multi-Society Task Force on Colorectal Cancer published their newest recommendations for colon cancer screening.[1] This update from the 2008 guideline reflects the new evidence and understanding of the disease state obtained since that time. Let me give you some snapshots of what's new about this that you need to know as a clinician.

Which Screening Method Is Right for You?

These guidelines have a unique approach by looking at the way in which people are screened.

There's the programmatic screening typically done by large health systems, such as Kaiser Permanente. In this type of screening, systems are uniformly rolled out to ensure that patients are notified; there is adequate follow-up; and if they do not comply or if there is a positive test, they are then generated into logical sequential tests, in particular colonoscopy.

Programmatic testing is not what most of us do in our day-to-day practice. Here, we tend to use opportunistic testing—where the patient comes in and has a dialogue with their care provider, who informs them that it's time for colon cancer screening.

There are different ways this can be approached, including giving the patient multiple options, such as colonoscopy or a fecal immunochemical test (FIT) test. If they say no to that, they would be offered some other tier of options, which we'll go through in a moment.

Giving patients the nine different tests that are currently commercially available for colorectal screening is likely to confuse them. Research conducted by John Inadomi and colleagues[2] at Washington State University analyzed the effect of offering multiple screening options and found that, in general, two to three options is the sweet spot that patients really respond to. You can give patients one option, and if they say no, give them a couple additional options, but after that it can get too confusing.

Another option is the sequential approach, in which you tell the patient something like, "As your gastroenterologist, I would recommend a colonoscopy." If they say no to that, then I'll default to the next available test. So you can give the patient the choice of multiple options by having them choose from sequential options using your prioritization.

The third option is the risk-stratified approach. Here, you inform patients that although these are great tests, you would offer them a tier 1 option owing to what we now recognize as pivotal risk factors. This could include being male, their age, smoking history, family history, and obesity, with diabetes as something that is now considered. Those are the factors you would perhaps consider in a risk-stratified approach.

The Task Force concluded that although none of these screening methods has been tested against each other to determine which is best, it is nice to have options. When it comes to programmatic screening, opportunistic screening with multiple options, the sequential approach, and the risk-stratified approach, they all seem reasonable to discuss with your patients.

Ensuring High-Quality Colonoscopies

The next area that the Task Force looked at was specific screening tests.

Beginning with colonoscopy, they analyzed all of the data and recognized that there are some complications related to this on both the gastrointestinal (GI) and the non-GI side, although these are relatively rare in expert hands, especially in screening tests.

The Task Force also emphasized that the use of cold snare in colonoscopy has become very safe and effective, with almost no delayed bleeding risk. It's something that I routinely do in patients on antiplatelet therapy or anticoagulants, for sessile polyps smaller than 1 cm. Although not officially recommended by the Task Force, cold snare is certainly now a part of the dialogue surrounding colonoscopy.

Ensuring high-quality colonoscopies has also become a real issue. We have to recognize the impact of the operator on quality, not as a way of positioning gastroenterology against other specialties performing this, but instead to ensure that all operators are held accountable.

I would also put in a huge plea that you need to be accounting for your quality metrics: adenoma detection rates (ADRs), cecal intubation, and compliance with surveillance intervals. These are things that really resonate, particularly with insurance companies, but also allow you to build your operational database to demonstrate expert quality performance.

The Task Force went as far as to generate tools to enhance colonoscopy quality, including questions for the patients to ask us. One of these questions is, "What is your ADR?"

We know the ADR should have a blended rate of 25% or greater: 30% for males and 20% for females. However, if you are not reporting and recording it in a way that you can later provide when needed, you are potentially subject to some risk.

I really plead with you that if you are not involved in the GI Quality Improvement Consortium (GIQuIC), then you need to be. This is registered now with the Centers for Medicare & Medicaid Services as an approved database, and it meets all of the metrics for a variety of reporting, and some of the quality metrics that will be important for penalties in the next several years.

In addition to the question about the ADR, the Task Force recommends that patients ask you, "What is your cecal intubation rate?" This should be 95% or greater in screening, and 90% overall.

Then the last question is, "What do you do in your preps? Do you do split-dosing?" When we had the US Multi-Society Task Force on preps, we said that was a standard of care. The exception is same-day prep, but again, that is very rare in most of our practices.

It's also very important that the endoscopy report include photodocumentation. I am aware of some insurance companies right now that do not pay unless you have photodocumentation. Therefore, you should have photodocumentation of the cecum, appendix orifice, terminal ileum, et cetera.

Finally, adequacy of the bowel prep should also be a part of your report.

These reports should be setting new standards as far as colonoscopy quality.

Other Screening Methods: Tiers of Recommendations

Another thing to consider is FIT testing.

It was around a year ago that the US Multi-Society Task Force, led by Douglas Robertson, released a publication providing a superb overview of FIT testing.[3] This overview recognizes that FIT has very much replaced fecal occult blood testing. The downside of FIT is the detection of serrated lesions. This is really not a good test generally for adenomatous polyps and advanced adenomas, and it is very poor for serrated lesions.

Fecal DNA testing incorporates FIT and is superior as it relates to identifying serrated lesions, given that it uses a hypermethylation pathway assessment, which is what most serrated lesions involve. The downside is that it is incredibly expensive—around $600 commercially and over $500 for Medicare. So you have to consider the cost and whether it is worth it. Patients like it because they don't have to fool around with stool, and instead add an insert to their toilet, collect the sample, and then mail it out for analysis.

CT colonography received an acknowledgement as an alternative to barium enema in the previous guidelines, but it has a very limited application. Most of the studies show that it still requires a prep. The radiation exposure is an issue. Even radiologists preferred CT colonography as a second choice to colonoscopy, in a recent paper published in their journal.[4]

There was a bit of a twist when it came to flexible sigmoidoscopy, which is recognized to be a great colon cancer screening test. Previously, it was recommended to administer this test every 5 years, but the Task Force recognized there were very few data on that, and also that it is very rarely used in this country, particularly owing to the lack of sedation. The Task Force suggested that the primary recommendation be to administer this every 10 years, or every 5 years; they're recommending the latitude to choose, but their first choice was every 10 years, on the basis of available data.

The next test is capsule colonoscopy, for which data are still emerging. This procedure is approved by the US Food and Drug Administration (FDA), in particular for failed completion of colonoscopy, but it is not yet covered [by insurance] for screening. There are compliance issues with insurance, which lowers the likelihood that this will get paid for. Therefore, it was not a high recommendation, although the Task Force recognized that more trials are pending and the data look quite good so far.

Septin 9 (SEPT9) is a blood serum analysis providing another avenue of assessment, whereby serologic testing might fit in very nice. A study looking at colon cancer screening compliance found that patients who refused colonoscopy would accept the SEPT9 assay.[5] This is a commercially available test. When the Task Force looked at this in prospective trial screening, they determined that it did not meet the criteria to be incorporated into the guideline as a formal recommendation.

The Task Force broke down their recommendations according to tiers. Tier 1 includes colonoscopy, which is done every 10 years in average-risk patients, and the FIT test annually. Tier 2 includes CT colonography every 5 years; the fecal DNA test every 3 years; and flexible sigmoidoscopy every 10 years or every 5 years, depending on preference. Tier 3 includes capsule colonoscopy, which again presents difficulty for insurance reasons. Not recommended, at least at present, is the SEPT9 test.

Populations at Risk

The next question, which comes up very frequently in my practice, surrounds special populations. What about family history? What about other special recognitions?

The Task Force—and this is agreed on by all three of the GI societies—said that screening should begin in African American persons at age 45 years. We recognize African American persons have earlier onset and more aggressive disease. So, begin at 45 years in African American persons, and then follow them at that point on the basis of whatever your findings are for their average risk if there are no polyps or neoplastic polyps, and otherwise directed by polyp surveillance guidelines. So this is a new recommendation from the US Multi-Society Task Force, and one previously recommended by the American College of Gastroenterology and the American Society of Gastrointestinal Endoscopy.

When it comes to family history, there is no real change here.

The discriminant age seems to be 60 years. If [a patient has a first-degree relative who was diagnosed at] 60 years or older, that patient would be followed at a decade shift. That is, the recommendations [for screening] begin at 40 years rather than 50 years, and then [the patient is followed as average-risk.

Patients with two first-degree relatives of any age get surveyed or screened at an age 10 years before the earliest cancer [diagnosed in the first-degree relative], and then followed at 5-year intervals.

The Task Force wrestled with what to do with [a family history of] advanced adenomas, because it is not often that our patients come in with a histology report from one of their relatives. If we could put more concrete data around it, [patients with a family history of] advanced adenomas would be followed [in the same way] as [those with] a colon cancer in a first-degree relative. Those would be decade-shifted [that is, 10 years before the relative with earliest onset of colon cancer], and then followed at 5-year intervals after the initial exam.

When to Intervene in Younger and Older Patients

The next area that really comes up all the time is the variable of age.

There is a growing recognition that although we are doing very well with a reduction in colon cancer incidence of almost 3% per year over the past decade, we are seeing an increase in colon cancer, in particular rectal cancer, in younger patients in their 20s, 30s, and 40s. What do we do with those patients?

The Task Force looked at the data and said that there is clearly a signal there, but not enough to change uniformly the threshold demand for screening at age 50 years or at age 45 years for African American persons. In particular, the key point here is looking for pivotal signs of bleeding. Signs of bleeding are overt bleeding, iron deficiency, or unexplained melena or malodorous stool. In the younger patient, bleeding is the index threshold to aggressively pursue with colonoscopy.

The other symptoms that patients tell us about are change in bowel habits, constipation, or change in the color of the stool. When these have been looked at, they have not been incrementally beneficial as far as detection of cancer. The threshold sign is bleeding in patients under the age of 50 years, or 45 years in the African American population.

The next pivotal question is, when do we stop? You have some patients who say, "How much longer do I need to do this?" Then you have these other patients who are getting older who say, "Don't give up on me. What else do you know about me?"

The US Preventive Services Task Force[6] said that the age of 75 years is the threshold where it starts to get into murky territory, with grade C evidence, whereas the age of 80 years starts to get into grade C-D evidence, and the age of 85 years is absolutely when not to do screening exams.

The [US Multi-Society] Task Force suggested that the incremental risk for cancer is evident up to the age of 85 years, and if somebody has never had a cancer screening test, you should consider screening those people. How is up to you, and relative to their overall risk. That is where screening at least should be considered. We are talking about screening now, not surveillance, which is a whole different topic and has to be risk-adjusted on the basis of the individual. But, in the patients who have never been screened, you would at least have to have a discussion.

The question of when to stop comes down to their comorbidities and life expectancy. Basically, it shows [that patients with] comorbidities [that result in] a life expectancy of less than 10 years [should not be screened]. That becomes a dialogue with the patient. This is not necessarily about screening you anymore. We are happy to respond to signs or symptoms, but again, it does not reflect appropriate screening. We have to start to draw that in. It does not mean that we are giving up on you, but it means that we give you a hall pass here. Some of these patients may have incident cancer that may not be causal as it relates to signs or symptoms that cause them harm.

Applying New Guidance to Your Practice

The Task Force did a great job in giving us some guidelines that I think are clinically reflective.

The highlights include looking in a bifurcated way of screening programmatically or opportunistically; the three-tier approaches and how we can operationalize those; and patient age in relation to when to start and when to stop. Don't forget the discriminant bleeding in patients who are younger than 50 years or 45 years [for African American persons]. They should have colonoscopy. Short of that, they should be evaluated but not necessarily with colonoscopy – that is where the bang for the buck comes in. Then we look at the age to stop as we start to look at comorbidities, including the 10-year life expectancy.

You should have these conversations with your patients so that you can put everything in perspective. Some will enjoy the hall pass; others will want one more screening. These are things that are meant to be risk-adjusted. Always do the best for your patient.

The Task Force has given us new guidance, which you should pay attention to and apply in your practice.

Refer to the quality issues that I alluded to, including providing photodocumentation in your endoscopy report and responding to patient questions about your ADR, how you do your preps (ie, is it a split-prep), and what your cecal intubation rate is. We should all know these answers, and the best way to do so is to document that. If you are not participating in the GIQuIC, you should be. Using some national registry database is ever more important, both for quality reporting and for obtaining a financial advantage, but also because it is the right thing to do.

I am Dr David Johnson. Thanks again for listening.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: