In the JournalsPerspective

USPSTF colorectal cancer screening guidelines challenged

In an opinion essay published in Annals of Internal Medicine, several European clinicians argue that the current colorectal cancer screening recommendations by the U.S. Preventive Services Task Force lack strength and quality of evidence.

“We are surprised by the latest update of the recommendations for colorectal cancer screening from the U.S. Preventive Services Task Force (USPSTF),” Michael Bretthauer, MD, PhD, from the KG Jebsen Center for Colorectal Cancer at the University of Oslo in Norway, and colleagues wrote. “Contrary to the principles of evidence-based medicine, the guidelines provided equally strong recommendations for tests with very different quality of evidence for benefits and harms.”
Bretthauer and colleagues note that despite the screening tests differing significantly in mode of action, invasiveness and quality of evidence for effectiveness and cost-effectiveness, the USPSTF graded all tests as a single test.

They also point out that guaiac-based fecal occult blood testing (FOBT) and sigmoidoscopy were the only two strategies recommended by the USPSTF for colorectal cancer screening that offered high-quality data. The remaining five strategies — colonoscopy, fecal immunochemical testing (FIT), computed tomography colonography, FIT DNA testing and a combination of sigmoidoscopy and annual FIT — have not been tested in clinical effectiveness trials, yet are as strongly recommended as FOBT and sigmoidoscopy. Bretthauer and colleagues reason that these strong recommendations may be justifiable even though they present low quality of evidence for benefits; however, the USPSTF did not give an explanation.

In addition, the authors highlight the fact that the USPSTF recommendation of sigmoidoscopy in combination with annual FIT screening did not correspond with trial data. Mortality from colorectal cancer was not significantly different in sigmoidoscopy alone vs. sigmoidoscopy plus FIT. The combined strategy demonstrated a trend toward better effectiveness; sigmoidoscopy alone demonstrated a trend toward better incidence. Furthermore, the experts emphasize that the recommended sigmoidoscopy plus annual FIT has not been tested in any of the trials mentioned.

“To generate high-quality evidence for effectiveness of new screening strategies, we consider the integration of high-quality clinical trials into ongoing screening programs as the only viable solution,” Bretthauer and colleagues wrote.

“We hope these trials will give some of the answers we lack to provide individuals, decision makers, and health care workers with the evidence base needed for informed decision making,” they concluded. “We believe that guideline makers have an important role in facilitating this development and encourage them to participate in the process.” – by Alaina Tedesco


Disclosure: The authors report no relevant financial disclosures.


In an opinion essay published in Annals of Internal Medicine, several European clinicians argue that the current colorectal cancer screening recommendations by the U.S. Preventive Services Task Force lack strength and quality of evidence.

“We are surprised by the latest update of the recommendations for colorectal cancer screening from the U.S. Preventive Services Task Force (USPSTF),” Michael Bretthauer, MD, PhD, from the KG Jebsen Center for Colorectal Cancer at the University of Oslo in Norway, and colleagues wrote. “Contrary to the principles of evidence-based medicine, the guidelines provided equally strong recommendations for tests with very different quality of evidence for benefits and harms.”
Bretthauer and colleagues note that despite the screening tests differing significantly in mode of action, invasiveness and quality of evidence for effectiveness and cost-effectiveness, the USPSTF graded all tests as a single test.

They also point out that guaiac-based fecal occult blood testing (FOBT) and sigmoidoscopy were the only two strategies recommended by the USPSTF for colorectal cancer screening that offered high-quality data. The remaining five strategies — colonoscopy, fecal immunochemical testing (FIT), computed tomography colonography, FIT DNA testing and a combination of sigmoidoscopy and annual FIT — have not been tested in clinical effectiveness trials, yet are as strongly recommended as FOBT and sigmoidoscopy. Bretthauer and colleagues reason that these strong recommendations may be justifiable even though they present low quality of evidence for benefits; however, the USPSTF did not give an explanation.

In addition, the authors highlight the fact that the USPSTF recommendation of sigmoidoscopy in combination with annual FIT screening did not correspond with trial data. Mortality from colorectal cancer was not significantly different in sigmoidoscopy alone vs. sigmoidoscopy plus FIT. The combined strategy demonstrated a trend toward better effectiveness; sigmoidoscopy alone demonstrated a trend toward better incidence. Furthermore, the experts emphasize that the recommended sigmoidoscopy plus annual FIT has not been tested in any of the trials mentioned.

“To generate high-quality evidence for effectiveness of new screening strategies, we consider the integration of high-quality clinical trials into ongoing screening programs as the only viable solution,” Bretthauer and colleagues wrote.

“We hope these trials will give some of the answers we lack to provide individuals, decision makers, and health care workers with the evidence base needed for informed decision making,” they concluded. “We believe that guideline makers have an important role in facilitating this development and encourage them to participate in the process.” – by Alaina Tedesco


Disclosure: The authors report no relevant financial disclosures.


    Perspective

    Kirsten Bibbins-Domingo

    The Task Force’s review of the evidence on screening for colorectal cancer clearly showed that screening works and can save lives. We recognize that there are many different screening tests with varying levels of evidence supporting their effectiveness, as well as different strengths and limitations, and we detail these in our recommendation statement. We also highlight the lack of studies comparing screening strategies as an important research gap and encourage the types of studies the authors suggest in their commentary.

     

    Importantly, despite the overall effectiveness of colorectal cancer screening, not enough people are using this highly effective service. Our recommendation that adults aged 50 to 75 years get screened, and that those 76 to 85 years old consider screening based on their overall health and prior screening history, is not an assessment of any one particular test, but rather an acknowledgement that getting screened for colorectal cancer reduces your risk of dying from the disease.

    • Kirsten Bibbins-Domingo, PhD, MD, MAS
    • Chair of the U.S. Preventive Services Task Force
      Professor, University of California, San Francisco

    Disclosures: Bibbins-Domingo reports no relevant financial disclosures.