Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. CRC is largely preventable by identification and removal of colon polyps. Colon polyps are extremely common among adults 50 years of age and older, occurring in over 40 percent of individuals who undergo screening colonoscopy. People who have once had colon polyps identified are commonly recommended to undergo regular follow-up colonoscopy (surveillance) in hopes of preventing subsequent CRC. Of note, most people with polyps will never get CRC. Older adults, particularly those who are age 70 years and above, most of whom have a history of only small colon polyps, may benefit little from repeated colonoscopies because of the increased risks of colonoscopy due to age and co-morbidities and because of potentially limited life expectancy due to other competing medical problems, such that CRC may never be a problem for them. In addition, older adults may be hesitant to get repeated colonoscopy because of its associated risk of complications (e.g., bleeding, perforation, etc.) and inconvenience that becomes increasingly challenging with age. More surveillance options are needed to help address the concerns and challenges with repeated colonoscopies in this population of older adults with a history of low-risk polyps.
The fecal immunochemical test (FIT) is a noninvasive, stool-based test that is recommended and widely used in the United States and globally for CRC screening in average-risk adults 50 to 75 years of age. In addition, FIT is already standard of care as a surveillance option for patients with a history of low-risk adenomas in Canada and has been shown to be equivalent to colonoscopy for screening of certain high-risk populations (e.g., those with a family history of CRC). However, FIT’s role for surveillance among older adults who have a history of low-risk adenomas has not been studied in the United States nor among older adults who may benefit from this noninvasive surveillance approach.
To fill this critical gap in knowledge, the research team proposes a trial to compare the effectiveness of yearly FIT versus colonoscopy for cumulative detection of CRC and advanced polyps in older adults with a history of low-risk colon polyps (COOP Trial). Equally important, we will compare patient-reported outcomes of satisfaction with and trust in testing, cancer worry, perceived cancer susceptibility, and emotional benefits of surveillance between the two strategies.
We have developed a network of sites across the country excited to participate in the COOP Trial. These sites were selected based on institutional support, clinician leader engagement, prior successful conduct of trials in this area, racial/ethnic and geographic diversity, and an estimated large sample of older adults who would be eligible to participate. Our network of sites includes those serving historically underserved and rural communities. English- or Spanish-speaking adults 70 to 82 years of age with a history of low-risk colon polyps will be recruited at these sites through electronic or mailed invitation and be randomly assigned to receive either annual FIT or colonoscopy. All participants will be asked to complete a baseline and annual questionnaire and receive an annual phone call for monitoring. We will monitor their outcomes until the end of the five-year trial.
We strongly believe the results of this comparative effectiveness trial will bring meaningful change in the delivery of CRC prevention for older adults with a history of low-risk colon polyps and be readily adoptable into clinical practice. The ease of FIT testing because it is noninvasive, performed at home, and relatively inexpensive will likely be a welcomed surveillance option among older adults, who in general may be less interested in invasive testing due to the burdens and risks that increase with age. Healthcare providers and health systems can use the findings from this study to help patients make an informed patient-centered choice about managing surveillance of polyps.
The research team is working with patients; healthcare providers; and representatives from CRC advocacy organizations and support groups, health systems, and insurance companies to design and conduct this study. The panel of patient partners has already been actively engaged in the design of the study and has committed to participate in monthly research team meetings throughout the study. The stakeholder advisory panel will meet semiannually.