(205) Do we need a colorectal cancer screening programme for patients with cystic fibrosis?

Background: Adults with CF have higher lifetime risk of developing colorectal cancer (CRC), and premalignant colorectal polyps compared to the general population.[1] There are currently no UK or European guidelines for CRC screening in patients with CF. We aimed to evaluate the proportion of patients that would be eligible for CRC screening programme and to understand the utility and diagnostic yield of colonoscopy in CF patients in the absence of a CRC screening programme at a UK CF centre.

Methods: We collected data retrospectively from all patients attending the Manchester Adult Cystic Fibrosis Centre (MACFC) between 1st January 2010 to 31^st December 2020. Patients were included if they had a confirmed diagnosis of CF, were aged ≥30 years, and had undergone a colonoscopy within the ten year study period. Data was extracted from a MACFC patient database, patient records and the endoscopy reporting tool, using a customised data collection form.

Results: During 2010-2020, n=709 patients with CF attended MACFC. Of these, n=361 (51%) were aged ≥30 years, and n=135 (19%) were ≥40 years old and would have fulfilled the criteria for CF CRC screening colonoscopy in the USA[1]. 33/361 (9%) of patients with CF ≥30 years of age (mean age 44.8 ± 11.0 years, n=23 male, 39% Phe508del homozygotes ) underwent 39 colonoscopies between 2010-2020. Of the 33 CF patients that underwent an index colonoscopy, almost all (31/33, 94%) were for symptomatic indications, and only 2/31 (6%) were for screening in the context of a family history of CRC. Colonoscopy completion rate was 94.9%. Extended bowel preparation was used in 14/39 (36%) of procedures. Diagnostic views were achieved with standard preparation in 18/25 (72%) vs. 12/14 (85.7%) with extended preparation (p=0.44). At colonoscopy, in 11/33 (33%) of CF patients aged ≥30 years, 20 polyps were detected and removed, 5/20 (25%) of these polyps were 10-20mm size, overall polyp retrieval rate was 80%, and of those polyps retrieved 93.8% were pre-malignant and 87.5% were proven adenomas. The majority of the patients that underwent colonoscopy in this study were ≥40 years of age (24/33, 73%), and this age group also accounted for most of the patients who were found to have polyps (8/11, 72.7%). Over 10 years of follow-up, no patients in this study developed post-colonoscopy CRC. By contrast, of the CF patients ≥40 years of age that did not have a colonoscopy (111/135, 82.2%), four subsequently developed CRC, three of whom died from complications of their cancer.

Conclusions: In the absence of CF CRC screening guidelines in the UK, our data shows that colonoscopy is not performed routinely in patients with CF aged ≥40 years, with fatal consequences and strongly supports the development of a CRC screening programme. This subset of patients currently account for a large proportion of the adult CF population, which is likely to rise in the future due to increasing life-expectancy with CF. CF physicians practicing in adult CF units should be vigilant about early and preventable CRC in patients with CF.

Acknowledgements:

References: Hadjiliadis D, Khoruts A, Zauber AG, Hempstead SE, Maisonneuve P, Lowenfels AB. Cystic Fibrosis Colorectal Cancer Screening Task Force. Cystic Fibrosis Colorectal Cancer Screening Consensus Recommendations. Gastroenterology. 2018 Feb;154(3):736-745.e14. doi: 10.1053/j.gastro.2017.12.012.