USPSTF update: ‘Not enough’ people getting screened for colorectal cancer

The U.S. Preventive Services Task Force (USPSTF) has done some fresh thinking on the pros and cons of screening for colorectal cancer, posting updated recommendations June 15 in JAMA.

The statement’s key takeaway is that, for many Americans, the pros handily outweigh the cons, as colorectal cancer screening significantly cuts the disease’s death toll among adults between the ages of 50 to 75.

Takeaway two: Many more people in this age bracket could and should be availing themselves of screening opportunities, regardless of choice of screening method.   

The posting represents an update of USPSTF’s 2008 recommendations. That year the group called for screening colonoscopy, fecal occult blood testing or sigmoidoscopy beginning at age 50 and continuing to age 75.

In ’08 USPSTF also concluded that there wasn’t sufficient evidence to recommend for or against CT colonography. (The same went for fecal DNA testing.)

Just do it, eligible Americans

The June 2016 iteration downplays the emphasis on specific screening approaches in order to urge all average-risk, asymptomatic adults aged 50 to 75 years to get screening, period, since screening has by now proven so effective at saving lives.

About one-third of eligible adults in the United States have never been screened for colorectal cancer, the authors point out.

“The reasons for [the] gap between evidence and practice are multifaceted and will require sustained effort among clinicians, policy makers, advocates and patients to overcome,” write corresponding author Kirsten Bibbins-Domingo, MD, PhD, of UC-San Francisco and colleagues.

The option of screening adults between the ages of 76 and 85 has gotten USPSTF’s “C” recommendation rating, with the authors stating that screening in these years “should be an individual one, taking into account the patient’s overall health and prior screening history.

Considering CT colonography  

In their updated look at CT colonography, the authors confirm its value in various clinical scenarios while cautioning that the method can “result in unnecessary diagnostic testing or treatment of incidental extracolonic findings that are of no importance or would never have threatened the patient’s health or become apparent without screening (ie, overdiagnosis and overtreatment).”

Extracolonic findings with the modality “are common,” they add, “occurring in about 40 percent to 70 percent of screening examinations. Between 5 percent and 37 percent of these findings result in diagnostic follow-up, and about 3 percent require definitive treatment. As with other screening strategies, indirect harms from CT colonography can also occur from follow-up colonoscopy for positive findings.”

The updated USPSTF recommendations come just a week after a new study showed colonoscopy much better than CT colonography at detecting high-risk sessile serrated polyps in average-risk individuals.

En route to updating their colorectal cancer screening recommendations, the USPSTF also commissioned a study to determine the optimal starting and stopping ages, along with appropriate screening intervals, across the different available screening methods.

“[T]here is convincing evidence that colorectal cancer screening substantially reduces deaths from the disease among adults aged 50 to 75 years,” the authors conclude, “and that not enough adults in the United States are using this effective preventive intervention.”

JAMA has posted the updated recommendation statement in full for free.