Patients with cystic fibrosis should begin screening for colorectal cancer with colonoscopy at age 40 due to their increased risk for the disease versus the general population, according to new recommendations from the Cystic Fibrosis Colorectal Cancer Screening Task Force.
The task force based its recommendations on a review of the literature and a modeling study of screening strategies for colorectal cancer that estimated the costs and benefits of screening in patients with cystic fibrosis. Recommendations were considered final if they were accepted by 80% of the 18-member task force. The modeling study and the recommendations were published online Dec. 27 and Dec. 28, 2017, respectively, by Gastroenterology.
Decisions about colorectal cancer screening and surveillance in patients with cystic fibrosis should be based on shared decision making regarding treatment, comorbid conditions, safety, and quality of life, the task force said. In addition, it recommended that screening and surveillance be jointly managed by cystic fibrosis health care professionals and an endoscopist. Colonoscopy is the recommended screening examination, with the task force finding that evidence was insufficient to recommend CT colonography, stool-based tests, or flexible sigmoidoscopy.
The task force recommended that screening should begin at age 40 years and should be repeated every five years thereafter. Patients with cystic fibrosis who have adenomatous polyps detected on colonoscopy should have surveillance colonoscopy in three years, unless individual findings indicate that a shorter interval is needed; subsequent intervals should be based on the most recent endoscopic findings, the task force said.
Patients with cystic fibrosis who are at least 30 years of age and have adequately recovered from a solid organ transplant should begin colorectal cancer screening within two years of transplantation, unless they had a negative colonoscopy within the past five years, the task force said. Rescreening in this population should also take place every five years, and recommendations regarding the timing of surveillance colonoscopy also mirror those for patients with cystic fibrosis who have not had a transplant, according to the task force. Finally, the task force recommends that adults with cystic fibrosis who are having a colonoscopy receive intensive bowel preparation beforehand.
The task force authors noted that they did not designate an age at which to end colorectal cancer screening, since the modeling study did not find many differences in screening effectiveness by end age. However, they said it would be prudent to stop screening in patients who have a life expectancy of less than 10 years. The authors also noted that patients as well as clinicians may not be aware of the increased risk for colorectal cancer with cystic fibrosis and stressed that education will be necessary to increase adherence to recommendations.
While the task force authors recommend surveillance screening at three years for patients in whom adenomas have been detected and five-year rescreening in patients with previous negative findings on colonoscopy, they noted that clinical decisions should always be based on the most recent colonoscopy. “As more data become available, it is possible that different subpopulations will need more or less frequent schedules for rescreening and surveillance,” the task force wrote. “Our recommendations are making an effort to balance the risk of missing advanced [colorectal cancer] and minimizing the burden and risk of too frequent examinations.”