Low-Tech Outreach Methods Improve Colorectal Cancer Screening
September 26, 2017, by NCI Staff
Low-tech outreach approaches, such as mailed invitation letters and free testing kits, can help increase the number of people who get screened for colorectal cancer with either a colonoscopy or home stool test and complete the appropriate follow-up, results from a new clinical trial show.
Researchers reported the findings September 5 in JAMA.
“Our best efforts tripled screening process completion rates [compared with usual care], but we have much more room to improve,” said senior study author Ethan Halm, M.D., of the University of Texas Southwestern (UTSW) Medical Center.
Screening for colorectal cancer, the second leading cause of cancer-related death in the United States, has been shown to reduce deaths from this disease. Yet many U.S. adults are not up to date with colorectal cancer screening or do not follow up when their test results warrant follow-up.
The trial included a large number of minority and low-income patients, who have among the lowest rates of colorectal cancer screening in the United States.
“This [clinical] trial yields several important lessons in a real-world context,” wrote Michael Pignone, M.D., of the University of Texas at Austin, and David Miller, M.D., of Wake Forest School of Medicine, in an editorial accompanying the new study. “Screening rates for [colorectal cancer] in the United States are inadequate. Creative approaches are necessary to improve them.”
The trial was funded in part by NCI’s PROSPR program, which aims to better understand how to improve the screening process for breast, colorectal, and cervical cancer.
Multiple Barriers to Screening
The most commonly used colorectal cancer screening approach in the United States is colonoscopy. This method can detect cancer early and find and remove precancerous growths, or polyps, reducing the risk of death from the disease.
Another commonly used screening method is a fecal immunochemical test (FIT), which checks for hidden (occult) blood in patient-collected stool samples. Fecal occult blood testing has also been shown to reduce colorectal cancer deaths. For this test, it is recommended that people repeat the test once a year, and, if they have an abnormal test result (signs of blood in the stool), that they follow up with a colonoscopy to investigate the cause.
The U.S. Preventive Services Task Force recommends screening for colorectal cancer for average-risk adults ages 50 to 75 with either colonoscopy once every 10 years or a FIT test every year.
Dr. Halm noted that colorectal cancer screening detects more cancers and prevents more cancer deaths than screening for either breast or cervical cancer. But many barriers keep people from being screened, including fear of the procedure itself or, in the case of colonoscopy, the preparation; lack of access to care; and absent or inadequate doctor–patient discussions about screening.
Studies of colorectal cancer screening effectiveness “have demonstrated failures at each step in the screening process, which are associated with increased [colorectal cancer] mortality,” the study authors wrote. “[H]owever, most studies of screening strategies have focused on single steps in the screening process, with few comparing the effect of different screening methods on completion of the entire process over time.”
The study authors noted that screening process failure encompasses a range of factors that lead to incomplete screening, including not repeating a FIT test annually as recommended, not having a follow-up colonoscopy if a FIT test result is abnormal, not showing up for a scheduled colonoscopy, or an incomplete bowel prep for colonoscopy.
Testing Outreach in a Real-World Setting
The trial enrolled 5,999 adults 50 to 64 years of age who were not up to date with screening. All trial participants were receiving primary care in the Parkland Health and Hospital System, a large, publicly funded health system that cares for underinsured or uninsured patients in Dallas, TX.
Of the participants, 49% were Hispanic, 24% were black, 22% were white, and 0.6% had unknown race or ethnicity.
Participants were randomly assigned to one of three groups: colonoscopy outreach, FIT outreach, or usual care. Colonoscopy and FIT outreach included mailed invitation letters, free bowel prep or FIT kits, scheduling assistance, and reminder calls. Usual care consisted of whatever screening was recommended and ordered during any in-person clinic visits.
Over the 3-year study period, 38.4% of participants in the colonoscopy outreach group completed the screening process, compared with 28.0% of those in the FIT outreach group and 10.7% of those in the usual care group. Completing the screening process was defined as undergoing the recommended number of screenings as indicated, and, in the case of an abnormal test result, completing appropriate follow-up testing or treatment evaluation in a timely manner.
Although the colonoscopy invitation group in this study had a higher completion rate than the group that received the mailed FIT kit, “it may not have been a fair fight, because there are more chances for the FIT kit strategy to fail in a 3-year study,” Dr. Halm said.
There were two major reasons for failure of the FIT kit strategy, Dr. Halm said. More than one-third (37%) of those in the FIT outreach group did not repeat the test every year as recommended. Others had an abnormal test result and did not follow up with a colonoscopy in a timely manner.
The major reason for screening failure in the colonoscopy outreach group was that nearly half (44%) of participants did not initiate screening.
A more definitive study would compare the two strategies over 5 or 10 years, Dr. Halm continued.
More Work Needed to Improve Screening
The study had limitations as well, Dr. Halm said. It tested a limited set of outreach strategies, which the researchers deliberately chose to be simple and low-tech, and it did not include a counseling component to more formally address people’s underlying beliefs about colorectal cancer that could impede screening. The study also did not test strategies to change physician attitudes or practices regarding colorectal cancer screening.
“We know that once a doctor makes a recommendation for colorectal cancer screening, that increases the chances that a person will get screened. But discussions about screening don’t always happen,” said Dr. Halm. For example, he noted, doctors don’t always have time to discuss screening because other issues may be more urgent.
In addition, Drs. Pignone and Miller wrote, “Studies…suggest that few clinicians and patients are having high-quality, shared discussions about screening options.”
“We have much more work to do to ensure that people who have a lot to gain from colon cancer screening over time can get screening done,” Dr. Halm said. The strategy that a health system chooses must make sense for the patient population it serves, and patients must commit to doing what’s needed to make their chosen strategy work, he continued.
“Existing evidence suggests no single form of colorectal cancer screening promotion will be sufficient to achieve high rates of screening; instead, clinicians, health care administrators, and policy makers must work to combine different types of effective interventions,” Drs. Pignone and Miller wrote. “Helping patients identify the test to which they are most likely to adhere over time and then helping them follow through is likely to yield the greatest benefit.”
Or, as Dr. Halm put it, “The best test is the one that actually gets done."