USPSTF Issues Draft of New Colon Cancer Screening Guide

Veronica Hackethal, MD

October 07, 2015

The US Preventive Services Task Force (USPSTF) has posted online new draft recommendations for colorectal cancer (CRC) screening in adults and is seeking public comments and feedback until November 2.

The draft statement updates 2008 USPSTF screening recommendations for CRC, and includes two notable proposed changes. However, the guidance continues to recommend screening for all adults aged between 50 and 75 years, and is mostly the same as the last set of recommendations.

A newly proposed recommendation is the "selective" screening of adults aged 76 to 85 years, taking into consideration the patient's past screening history and overall health; people in this age group who do not have prior screening history are most likely to benefit. The recommendations to not support routine screening for people aged 86 years or over.

There is also a new recommendation to screen with flexible sigmoidoscopy every 10 years in combination with an annual fecal immunochemical test (FIT).

"Colorectal cancer screening is a very effective, but underused, health promotion strategy in the United States. The evidence is clear that adults ages 50 to 75 years will substantially benefit from getting screened, but about one third of these people have never done so," Task Force member Douglas K. Owens, MD, MS, a professor and director of the Center for Health Policy at Stanford University Medical School in California, said in a press release.

Colorectal cancer is the second leading cause of cancer death in the United States. Older age is the most important risk factor for colorectal cancer in the "vast majority" of patients, according to the statement. The disease predominantly affects people aged over 50 years, with most diagnoses occurring between ages 65 and 74.

The new draft recommendations result from a systematic evidence review and a modeling report commissioned by the USPSTF from the Cancer Intervention and Surveillance Modeling Network (CISNET) Colorectal Cancer Working Group. The modeling report compared optimal starting and stopping ages and screening intervals. The USPSTF concluded that the net benefit of CRC screening in adults aged 50 to 75 years is "substantial," that the net benefit of screening in adults aged 76 to 85 years who have had prior screens is "small," but that adults who have never been screened are "more likely to benefit."

Consequently, the USPSTF has recommended the following screening intervals for people aged 50 to 75 years:

  • FIT or guaiac-based fecal occult blood test (gFOBT): annually

  • Flexible sigmoidoscopy: every 10 years (plus FIT annually)

  • Colonoscopy: every 10 years

There are two main proposed changes are a help and hindrance, according to Chyke Doubeni, MD, professor of family medicine and community health at the University of Pennsylvania in Philadelphia.

The first concerns people aged between 76 and 85 years. Previous guidelines included people aged up to 85 years, but were not so clear on their management, Dr Doubeni explained. The new recommendations offer "a little more clarification," by recommending the importance of the patient's past screening history, and whether they have illnesses that could reduce their benefit from colon cancer screening. The new recommendations seem to support a shared decision-making model in this age group, with which Dr Doubeni "completely" agrees.

"I think that's a very useful recommendation," he said.

The second change — the recommendation to do flexible sigmoidoscopy every 10 years combined with annual FIT— came as a "bit of a surprise," Dr Doubeni revealed.

Past guidelines recommend flexible sigmoidoscopy every 5 years combined with FIT or gFOBT every 3 years. The change seems to stem from CISNET modeling studies suggesting that a combined screening approach would avert more CRC deaths than sigmoidoscopy alone, and randomized controlled trials suggesting that combined testing is better than flexible sigmoidoscopy alone, according to the statement. Still, the recommendation could cause confusion, according to Dr Doubeni.

"FIT is recommended on its own, and then it's recommended with sigmoidoscopy, so it's not clear to me whether that recommendation is saying that sigmoidoscopy is not good enough, or that FIT is not good enough," Dr Doubeni said. "That recommendation has the potential to be very confusing to people."

Despite these issues, "the guidelines are more the same than they are different," according to Dr Doubeni.

"Nothing has really changed in terms of the guidelines from what we have known before. Right now I view them as probably more confusing than helpful," he said. "If I was to put the message out there it's that people do not need to change what they're currently doing based on the old guidelines."

The new USPSTF draft recommendations focus mainly on patients aged 50 years or over who have average risk for colorectal cancer. Dr Doubeni pointed out that they do not directly address patients with increased risk for the disease, such as those with a family history of genetic disorders that could increase their risk for CRC (like Lynch syndrome or familial adenomatous polyposis), or those with a history of inflammatory bowel disease, polyps, or past CRC.

In a recent editorial in Gastroenterology, Dr Doubeni advocated for less aggressive screening in patients ≥ 55 years who have had one first-degree family member diagnosed with colorectal cancer before age 60, recommending that such patients should follow screening recommendations for average-risk patients. Patients with two or more first-degree relatives diagnosed with the disease at any age should still be screened more aggressively, he wrote.

"The two most important factors in considering who should be screened, and how they should be screened, is family history and age," Dr Doubeni emphasized, while pointing out that gastroenterologists may need to weigh in on this issue in the USPSTF draft recommendations.

CT Colonography Left Out

The new draft recommendations also fall short of recommending CT colonography and multitargeted stool DNA (FIT-DNA), which the USPSTF statement says may be useful in "select clinical circumstance." The evidence for these tests is "less mature," according to the statement, which cites concerns about incidental extracolonic findings and radiation exposure associated with CT colonography.

In a press release, The Medical Imaging & Technology Alliance (MITA) expressed concern about the exclusion of CT colonography from the USPSTF recommendations. MITA cited several studies in support of its pro-CT colonography stance, including a recent study published in Abdominal Imaging confirming the cost-effectiveness of CT colonography for the Medicare population, several past national studies supporting the value of CT colonography, and the 2008 ACRIN trial, published in the New England Journal of Medicine, supporting the accuracy of CT colonography in people aged 50 years or older. MITA plans to provide a formal response to the USPSTF.

"It is disappointing USPSTF disregarded the abundance of evidence showing that CT colonography is a better, more patient-friendly alternative to traditional optical colonoscopy," Patrick Hope, MITA's executive director, said in a press release. "Colon cancer screening is already dramatically underutilized, and we believe greater acceptance of CT colonography would likely increase access to early detection and life-saving treatment. It is our hope that upon review of our comments, USPSTF will endorse CT colonography for colon cancer screening."

Failure by the USPSTF to endorse CT colonography could be a blow to Medicare beneficiaries because it likely means that Medicare will decide not to reimburse the procedure, according to an article on AuntMinnie.com. The Centers for Medicare and Medicaid Services generally agrees with USPSTF recommendations.

The draft recommendation statement and draft evidence review can be found at www.uspreventiveservicestaskforce.org. Comments can be posted until November 2, 2015, at www.uspreventiveservicestaskforce.org/tfcomment.htm.

Dr Doubeni reports consulting for Exact Sciences in 2014 to prepare for their FDA review.

USPSTF. Draft Recommendation Statement for Colorectal Cancer Screening. Published online October 5, 2015. Full text

Gastroenterology. Published online September 25, 2015. Editorial

Comments

3090D553-9492-4563-8681-AD288FA52ACE
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:

processing....