Health News Review

Breast cancer expert Dr. Susan Love wrote on her Facebook page last week:

“Had my routine colonoscopy today…did you know that there is no study showing that screening colonoscopy is better than sigmoidoscopy in reducing deaths from colon cancer…. and yet the beat goes on.”

She also linked to a public radio Marketplace piece, “Should the colonoscopy be the ‘gold standard’?

We’re starting to hear this question more often.

And many times, it’s being asked by Dr. James Allison, an emeritus professor at the University of California-San Francisco in the Division of Gastroenterology.

Last week he wrote to colleagues on the California Colorectal Cancer Coalition about new American Cancer Society colorectal screening guidelines. Excerpt of his email letter:

“I was optimistic when I saw the headline today but it appears this “new” screening guideline looks exactly like the old one. It once again puts out the statement not supported by the available evidence that structural exams detect and prevent cancer but fecal tests (FOBT/FIT) do not.

Tests continue to be recommended that have not, after careful CMS (Center for Medicare & Medicaid Services) review, been approved for Medicare reimbursement (virtual colonoscopy, fecal DNA test), have not been FDA approved and have performance characteristics inferior to FIT or fecal immunochemical test (Mayo Clinic/NCI sponsored study-fecal DNA test), have no data suggesting efficacy (air contrast barium enema, fecal DNA test) or are no longer used very much in the U.S. (flexible sigmoidoscopy, air contrast barium enema). They also fail to mention that the increase in endoscopic screening since 2000 is almost exclusively due to colonoscopy screening and that Medicare data reveals that the use of sigmoidoscopy fell 54% from 1993 to 2003 with most of the fall occurring after Congress bypassed CMS and approved Medicare reimbursement for screening colonoscopy in 2001. Over the same period there has been a 6 fold increase in colonoscopies. Sadly, as we know too well, the vast majority of this increased screening has been in the insured population.”

He believes that the guidelines may “scare off the ever growing uninsured underserved population we are targeting for screening by saying, without evidence, that the test we recommend is inferior.”

ADDENDUM on March 15: The American Cancer Society points out that its guidelines on colorectal cancer screening were last updated in March of 2008, and have not changed in the interim. Dr. Allison’s letter to the California Colorectal Cancer Coalition referred to the ACS’ new report on Colorectal Cancer Facts and Figures, which included reference to the 2008 guidelines.

Comments

Len Lichtenfeld, MD, MACP posted on March 15, 2011 at 11:04 am

I would like to respond to this blog with clarifications regarding the positions of the American Cancer Society with respect to colorectal cancer screening and colonoscopy in particular.
The Society has not issued any new guidelines on colorectal cancer, so I am uncertain as to where that thought originated. Our guidelines were last updated in March of 2008, and appear in our journal CA and on our website at http://www.cancer.org. They have not changed in the interim.
As we clearly explain in the guidelines, there are several tests that can detect polyps before they become malignant, and those tests were listed as “preferred.” Those tests do include colonoscopy, but they also include sigmoidoscopy, CT colonography, and even barium enema. The fecal occult blood tests (FOBT) and fecal immunochemical tests (FIT) primarily are used to detect cancer, although the guidelines clearly note they can also occasionally detect polyps if there is sufficient bleeding. Our expert panel was of the opinion that preventing cancer was a preferred strategy over detecting cancer, thus the differentiation.
We have never–let me repeat, never–endorsed colonoscopy as a “gold standard.”
Our guidelines state the following: “Finally,colonoscopy is not an infallible ‘gold standard.’ Controlled studies have shown the colonoscopy miss rate for large adenomas (10 mm) to be 6% to 12%. The reported colonoscopy missrate for cancer is about 5%.”
We were as upset at the Marketplace interview as others appear to be, and we immediately contacted Marketplace and asked them to make a complete retraction. Their somewhat lukewarm statement does appear on their website. In fact, the comment came from one of our colleagues who is not an expert in colorectal cancer screening and made clear to the interviewer he was not an expert in colorectal cancer screening. It was an unfortunate comment to which we reacted immediately.
We have always recognized the value of fecal occult blood tests as proven means of reducing colorectal cancer deaths–and frequently state in our presentations that they remain a useful option. FOBT is the only test that has been demonstrated in a clinical trial to actually reduce mortality.
In fact, our guidelines clearly state in the text: “gFOBT are the most common stool blood tests in use for CRC screening and the only CRC screening tests for which there is evidence of efficacy from prospective, randomized controlled trials.”
The problems we face are that patients do NOT do the test every year, which is critical for its performace characteristics. Similarly, I might add, sigmoidoscopy skills and availability have declined over decades–as I have personally witnessed–because of a number of factors including limited if any training of primary care physicians in that procedure.
Finally, we have always maintained that informed discussion between a health care professional and a patient is key to successful colorectal cancer screening. Our position is that the test you get rather than which test you get is the important focus for reducing the deaths and burden of colorectal cancer screening.
People will make assumptions that they make for whatever reasons they choose. But as noted above, the statements made by others do not reflect what we have published and lectured on regarding colorectal cancer screening.

Elaine Schattner, MD posted on March 15, 2011 at 1:14 pm

Len,
Thanks for your helpful clarification on this issue.

James Allison MD, FACP,AGAF posted on March 15, 2011 at 10:07 pm

Dear Dr. Lichtenfeld:
I have great respect for all you do for the American Cancer Society (ACS) and all the ACS does for its constituents. In California they are an army of helpers working with the California Colorectal Cancer Coalition (C4) to bring screening to the uninsured and underserved of our state. Without their help we couldn’t have achieved the success we have had so far by developing a FIT based screening test model to increase screening in the uninsured/underserved patients in our state, a patient population that has seen little if any CRC screening let alone increase in screening since the endoscopy societies endorsed colonoscopy as the “best or preferred” screening test in 2000.
I apologize for thinking that a new CRC guideline had been produced by the ACS but I was misled by the announcement which I read in a daily news output (Today in Medicine) that members of the American Gastroenterological Association (see below) receive each morning. Since the AGA is one of the members of the American Cancer Society Multi Society CRC Screening Guideline Task Force, I assumed this was accurate though I had not heard of a new guideline in preparation. Below is the announcement and you can see why I was confused.
Group Releases New Colorectal Cancer Data, Screening Guide.
Medscape (3/10, Chusteck) reported that most colorectal cancer “could be prevented by applying existing knowledge about cancer prevention and by increasing the use of established screening tests,” according to a new report released by the American Cancer Society (ACS). In the “Colorectal Cancer Facts & Figures 2011-2013,” which was released to coincide with National Colon Cancer Awareness Month, the ACS recommends “colorectal cancer screening for people 50 years and older.” The group also encourages “physicians to proactively recommend regular screening,” and highlights its online resource, entitled “How to Increase Colorectal Cancer Screening Rates in Practice: A Primary Care Clinician’s Evidence-Based Toolbox and Guide.”
I want to be very clear that I have never said that the ACS/MSTF Guidelines endorsed colonoscopy as a “gold standard.” What they do, however, is present alternative “preferred” tests that, as mentioned in my letter to the C4 Board have not, after careful CMS (Center for Medicare & Medicaid Services) review, been approved for Medicare reimbursement (virtual colonoscopy, fecal DNA test), have not been FDA approved and have performance characteristics inferior to FIT or fecal immunochemical test (Mayo Clinic/NCI sponsored study-fecal DNA test), have no data suggesting efficacy (air contrast barium enema, fecal DNA test) or are no longer used very much in the U.S. (flexible sigmoidoscopy, air contrast barium enema).
As you are aware, the increase in endoscopic screening since 2000 is almost exclusively due to colonoscopy screening and that Medicare data reveals that the use of sigmoidoscopy fell 54% from 1993 to 2003 with most of the fall occurring after Congress bypassed CMS and approved Medicare reimbursement for screening colonoscopy in 2001. Over the same period there has been a 6 fold increase in colonoscopies. Sadly, as you know well, the vast majority of this increased screening has been in the insured population.”
Of all the preferred tests recommended in the ACS/MSTF guidelines, only optical colonoscopy is readily available, reimbursable by CMS and has a recommendation by both the ACS/MSTF and the USPSTF. Since the ACS/MSTF guidelines also state “If fecal tests are used the “opportunity for prevention is both limited and incidental and not the primary goal of CRC screening with these tests. It is the strong opinion of this expert panel that colon cancer prevention should be the primary goal of CRC screening and that providers and patients should understand that noninvasive tests are less likely to prevent cancer compared with the invasive tests.”, it is obvious the guidelines are recommending colonoscopy as the screening test of choice since the preferred tests other than colonoscopy are not readily available and fecal tests are deemed “not preferred”.
I would like to have you answer the following questions for me and the readers of this blog.
Question 1 – What is your evidence that patients do not do the new fecal immunochemical tests every year and what is your evidence that patients do colonoscopy every 10 years?
Question 2 – There is abundant evidence in the current literature that the FIT FOBT identifies 30% or more of the advanced adenomas present in a patient at each screen. Once identified, they are removed. Isn’t that preventing cancer and why would someone call call that number “incidental”?
Question 3 – What evidence do you have that structural exams prevent cancer and fecal tests do not? At the NIH sponsored conference on CRC screening tests last year in DC, Dr. Carrie Klabunde, Health Services and Economics Branch NCI Division of Cancer Control and Population Sciences and chairwoman of the conference, said the “USMSTF/ACS CRC guidelines state that tests providing a full structural examination of the colon are preferred over other tests. Not only do we lack randomized, controlled trial data to warrant such a preference, but there is evidence that other screening options that use colonoscopy as a diagnostic follow-up test can play a role in systems that achieve high screening rates.” Do you and the ACS disagree with her statement and, if so, what is your evidence?
Question 4 – If you were a patient that needed screening and didn’t have insurance, would you accept a test labeled as “not preferred” by the ACS/MSTF Guidelines and, if you are the recommending physician would you feel secure you wouldn’t be sued if the test was a false negative?
I’m not sure a blog is the proper place for this dialogue but, I want everyone to know that as far as I am concerned both C4 and the ACS are partners in efforts to increase screening for colorectal cancer in the ever growing uninsured population. I don’t think whatever is left of the Obama healthcare plan after Congress defunds many of its initiatives can be expected to fix the problem of poor screening rates anytime soon. I am hopeful that we can all be open minded and not defensive. Guidelines are made to be changed and improved as more evidence and experience accumulates. The ACS and other interested groups should be able to work together to make this happen.

Gregory D. Pawelski posted on March 16, 2011 at 12:54 pm

The standards used to judge the utility of laboratory and radiographic tests have always been (1) acceptable “accuracy” of clinical correlations (the test accurately measures what they are purported to measure, not that it improves clinical outcomes) and (2) clinical utility, in the judgement of the physician ordering the test. Diagnostic tests are judged by their performance characteristics (sensitivity/specificity), are they reproducible, favorable and provide information to physicians.

Jean Oliver posted on March 23, 2011 at 2:52 pm

The one thing I never see or hear mentioned about colon polyps is what the “possiblity” or chance is that they will turn cancerous. In other words, colonoscopy can detect and remove a large percentage of these polyps but what percentage of those polyps would ever have turned cancerous? I don’t think you can make a viable statement about saving lives if you do not know how many removed polyps would ever have presented a problem had they remained in the colon.
I think it would be a lot more economical and safe to first screen individuals with a FOBT or DNA stool test and then only refer those with positive results for a more invasive colonoscopy.

James Allison MD,FACP,AGAF posted on March 25, 2011 at 10:07 am

Excellent question. Here is the answer:
Facts about polyps:
1.Only 3% of all adenomas progress to cancer
2.Only 6% of patients in a screening population will be found to harbor an advanced adenoma (polyp).
3.Advanced neoplasia (most of these are polyps) may be considered a convenient proxy for colorectal cancer but its use as an outcome measure may be misleading in screening studies because the natural history of this lesion is unknown
4.The majority of screening colonoscopies will show no adenomas(polyps) or cancers and highlight the need to identify a way to estimate absolute risk for individual persons so that screening colonoscopy may be more efficiently targeted to those with advanced neoplasia.(This is your point)
5.Most polyps, even the “advanced” ones, do not directly lead to death from colon cancer
6.Only about 2.5/1000 polyps per year progress to cancer
7.Large polyps (>1cm) become colorectal cancers at a rate
of roughly 1% per year
8.A large polyp, left in place, has a cumulative risk of malignancy at 20 years of only 24%
9.The development of invasive cancer from a small (

Jean Oliver posted on March 28, 2011 at 8:37 am

It appears that #9 on the last answer from Dr. Allison got cut off somewhat. I am quite interested in the history of small polyps since I had one polyp only detected that was 4mm in size. (I was advised by one doctor to get a follow up colonoscopy in 3 years and by another doctor in 5 years!) Thank you very much for that answer. I have never seen this information on any medical websites or heard this from any doctors. Why don’t doctors inform patients of such information? Why can patients not make a judgement on whether or not they want an invasive colonoscopy after they are given more detailed information about risk, polyp developement, etc. instead of being “herded” into the procedure?

PEGGY DODGE posted on May 1, 2011 at 3:26 pm

Thank you for this site. As a 60 year old who has been agonizing over whether or not to have a routine colonoscopy, I value this information greatly. I am glad to know of the alternative tests and better yet, the statistics regarding polyps and cancer.

John L. Bove posted on May 20, 2011 at 12:46 pm

I had one….unpleasant….many problems surfaced after, none of which were cancer….got rid of them…should have shot the doctor…I asked questions prior to procedure…no answers…ansked more after and no answers….One lenghty study I found of some 40,000 patients concluded those who have colonoscopies did not fare so well as those who had tests for same problems…forgot the doctor who did the research…he concluded that anyone stupid enough to have an 8 foot (or whatever length) tub stuck up his or her rectum deserves the consequences. I am in total agreement from all the research I’ve seen. USE SOME OTHER METHOD–and as you can see the AMC has many which are approved.