(197) Rare prevalence of colonic sessile serrated lesions in cystic fibrosis patients

Thursday, November 3, 2022

12:45 PM – 1:25 PM ET

Presenting Author(s)

J. Alexander Torres, MD

Resident Physician
University of Washington
Newcastle, Washington, United States

Co-Author(s)

AS

Anand Singla, MD, MS

Clinical Assistant Professor
University of Washington, United States
JA

James M. Abraham, MD

Clinical Assistant Professor
University of Michigan, United States
Mark D. Derleth, MD

Clinical Associate Professor, Gastroenterology Fellowship Program Director
University of Washington, United States

Background:
It is well known that Cystic Fibrosis (CF) patients experience increased rates of early colon polyp development and progression to colorectal cancer compared to the general population, a trend further magnified in patients with solid organ transplant. In response, the CF Foundation developed colorectal cancer (CRC) screening guidelines in 2017 recommending initiation of earlier first screening colonoscopy with shorter re-screening intervals as compared to the general population. The exact mechanism for why CF patients develop more polyps and whether different polyp types occur at similar prevalence rates as the general population remains unclear. Recent studies suggest sessile serrated lesions (SSL) have a prevalence in the general population of 8.2% [1]. However, a detailed review of prior literature suggests CF patients may have different polyp type distributions [2]. We developed a database of colonoscopy results in CF patients to better characterize the prevalence of sessile serrated lesions.

Methods: In this retrospective chart review, patients were identified via the University of Washington (UW) CF Foundation Patient Registry. Inclusion criteria were patients with a diagnosis of CF and exclusion criteria were age younger than 18 years old. The patient’s electronic medical records (EMR) were accessed using the UW’s Epic EMR system including linked archival data systems to access partner health system data on the selected patients. The colonoscopy reports were systematically reviewed with selected variables including patient age at time of procedure, date of colonoscopy, bowel preparation quality, cecal intubation, polyp quantity, polyp size, polyp location within the colon, and whether cancer was present. Statistical analysis was performed to assess our data compared to the general population.

Results: 757 patients were identified from the CF registry. Of which, 170 patients had available records of prior colonoscopy, for any indication. 52.9% patients reviewed were women and 47.1% men. Mean age at time of colonoscopy was 43.2 years old. From these patients, 288 colonoscopy reports were reviewed. 270 total polyps, of all types, were identified. Two patients were found to have solitary SSLs (Table 1). SSL prevalence was 1.18%, significantly lower than what has been described in the general population (p< 0.05). There were 41 colonoscopies in our database pre-2010, from which 14 polyps were found; none of these polyps were hyperplastic or other serrated polyp type.

Conclusions:
At our center, CF patients had a significantly lower prevalence of SSLs compared to what has been described in the general population. The patients who did develop SSLs appear to follow age dependent trends typically seen in the general population. Low SSL prevalence may shed light on the tumor biology of patients with CF. Low prevalence of SSLs in CF patients may affect the utility and advantage of more expensive stool DNA tests as compared to fecal immunochemical tests for CRC screening.

Acknowledgements:

References:
[1] IJspeert JE, de Wit K, van der Vlugt M, Bastiaansen BA, Fockens P, Dekker E. Prevalence, distribution and risk of sessile serrated adenomas/polyps at a center with a high adenoma detection rate and experienced pathologists. Endoscopy. 2016 Aug;48(8):740-6. doi: 10.1055/s-0042-105436.

[2] Niccum DE, Billings JL, Dunitz JM, Khoruts A. Colonoscopic screening shows increased early incidence and progression of adenomas in cystic fibrosis. J Cyst Fibros. 2016 Jul;15(4):548-53. doi: 10.1016/j.jcf.2016.01.002.