Presence of Colonic Dysplasia prior to Colorectal Cancer Diagnosis is Associated with Early Stage Cancer among Patients with Inflammatory Bowel Disease: A National Cohort Study

Panara AJ, Zhang HC, Waljee AK, Gaidos J, Feagins LA, Thrift AP, El-Serag HB, Hou J. Presence of Colonic Dysplasia prior to Colorectal Cancer Diagnosis is Associated with Early Stage Cancer among Patients with Inflammatory Bowel Disease: A National Cohort Study. Poster session presented at: Digestive Disease Week Annual Conference; 2016 May 22; San Diego, CA.

Related HSR&D Project(s)

• CDA 11-217 – Risk Stratification and Targeted Therapy for HELP Diseases in Veterans

Patients with inflammatory bowel disease (IBD) are at an increased risk of colorectal cancer (CRC). Patients with significant colonic involvement are recommended to undergo surveillance colonoscopy to detect pre-cancerous dysplasia, however the association of CRC outcomes among patients with a prior diagnosis of dysplasia are unknown. The aim of this study was to evaluate the association of colonic dysplasia prior to CRC diagnosis on the stage of CRC. Methods: A national cohort of veterans from 1998-2012 with IBD and CRC were identified using ICD-9 codes, and validated by manual chart review for confirmation of both CRC and IBD. Data regarding IBD type, extent, duration, CRC stage and outcomes, and prior diagnoses of dysplasia were extracted by chart review. Early stage CRC was defined as stage 0 or 1 at diagnosis. The association of variables with early stage at diagnosis was evaluated. Characteristics were compared using the chi-square test for categorical variables. Results: From a cohort of 63,210 patients with IBD, x,xxx had codes for CRC. After chart review, 661 were confirmed to have both IBD and CRC and included in analyses. Our cohort was 98.5% male, xx% Caucasian, xx% African American, and xx other races. The distribution of IBD type was xx % ulcerative colitis, xx% Crohn's disease, and xx% IBD unclassified. Of patients with confirmed CRC at diagnosis, 22.9% had dysplasia detected prior to CRC diagnosis. Among patients with a known pre-CRC dysplasia, 38.5% had early stage CRC at diagnosis, and 61.5% had advanced stage (stages 2-4) at diagnosis. In contrast, among patients without a prior history of dysplasia, xx% had early stage CRC at diagnosis (p = 0.xxx). The mean time from first detected dysplasia to CRC was 3.33 years for early disease (range xx-xx years) and 4.64 years for late disease, (range xx-xx years) (p = 0.16). The indication for the colonoscopy diagnosing the CRC was surveillance in 46.4% patients with dysplasia. What was the % of surveillance among the patients without prior dysplasia? Conclusion: In our cohort of veterans, IBD patients with recognized pre-CRC dysplasia were more likely to have early stage CRC compared to patients without recognized dysplasia. We observed a mean of 3.33 years from dysplasia detection to CRC, which may guide surveillance intervals among IBD patients with dysplasia.