Cumulative Histologic Inflammation Predicts Colorectal Neoplasia in Ulcerative Colitis: A Validation Study.

Background: Chronic inflammation in ulcerative colitis (UC) is associated with the development of colorectal neoplasia (CRN). A group at St. Mark's Hospital reported a novel cumulative inflammatory index that predicted the development of CRN in UC patients that we validated with an independent, well-described, matched, case-controlled cohort from the University of Chicago.

Methods: Cumulative inflammatory burden (CIB) was calculated by summing each histological inflammatory activity (HIA) score and multiplying it by the length of the surveillance interval. Persistency was defined by the number of surveillance episodes (with a severity score >2) divided by the total number of surveillance procedures. T tests compared the mean and maximum HIA scores, assessing mean and maximum severity, CIB, and persistency.

Results: Sixty-two UC patients (26 patients with CRN, 36 control patients without CRN) were analyzed. Fifty-five percent were men, mean disease duration was 20.6 years, and mean age at CRN diagnosis was 43.9. Of the CRN patients, 6 (23%) had colorectal cancer, 16 (62%) had low-grade dysplasia, and 4 (15%) had indefinite dysplasia. Using mean HIA scores, we found CIB to be statistically greater in CRN patients (P = 0.04). Using maximum HIA scores, we found CIB (P = 0.02), mean severity (P = 0.03), and persistency (P = 0.01) to be significantly greater in CRN patients. Maximum severity was numerically greater for mean and maximum HIA scores but did not reach significance.

Conclusion: Cumulative histologic inflammation is significantly associated with the development of CRN in UC patients. This suggests a management strategy of controlling inflammation to reduce the risk of CRN and may influence the selection of surveillance intervals.