CYSTIC FIBROSIS COLORECTAL CANCER SCREENING: A SINGLE CENTER EXPERIENCE
D. Niccum1, K. Rank2, J. Billings1, J. Dunitz1, & A. Khoruts2
Background:The median life expectancy in individuals with cystic fibrosis (CF) hasdramatically increased over the past 30 years. CF is associated with an increased risk of colon cancer. General guidelines for colon cancer screening, which recommend initiation at age 50, may not apply well to the adult population with CF. Our center has instituted a dedicated colon cancer screening program for CF patients and published the initial experience with 45 patients. However, data on systematic colon screening of CF patients remains very limited. Here we presented updated results from our program.
Methods: A single center retrospective chart review was performed on all patients with cystic fibrosis over the age of 40 who underwent screening or diagnostic colonoscopy at the University of Minnesota. Our screening criteria includes individuals with CF who are aged 40 and older and who have an FEV1>50%. All patients currently enrolled in the University of Minnesota’s Cystic Fibrosis Database were included in analysis to determine current compliance with our set guidelines. Results of diagnostic colonoscopies performed on CF patients over the age of 40 since 2008 were also analyzed separately. Multiple variables including patient sex, genotype, history of diabetes, pancreatic insufficiency, and organ transplant status were analyzed for an association with colon polyp formation and high-risk colon polyp formation.
Results: Of the 111current patients in the CF databasequalified for screening. 82 patients have undergone colonoscopy between 2008 and 2015. A high rate of adenomatous polyp formation was found with 43 (49%) on the initial examination and 49 (56%) of patients having polyps on any colonoscopy. Polyps with advanced pathology were found in 20 (23%) of patients. Colorectal cancer was discovered in 3 (3%) of patients. Multivariate analysis demonstrated a statistically significant association between colon polyp formation and patients who had either CF related diabetesor who were delta F508 homozygotes. Patients who were male or who were status post lung transplantation had a statistically higher risk of developing either multiple or histologically advanced colon polyps.
Discussion:It is increasingly important to recognize that CF is also a colon cancer syndrome, which deserves special considerations for screening and surveillance. This study demonstrateda very high rate of advanced adenomas and colon cancers in patients aged 40 and above comparable to that of nonagenarians in the general population. Given this, general colon cancer screening guidelines are not likely to be adequate in this patient population.
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