Stage at Diagnosis and Survival of Colorectal Cancer With or Without Underlying Inflammatory Bowel Disease: A Population-based Study

Inflammatory bowel disease [IBD] is a risk factor for colorectal cancer [CRC]. The aim of this study is to determine whether stage at diagnosis and survival differ between sporadic, ulcerative colitis [UC]- and Crohn's disease [CD]-related CRC.The English National Cancer Registry [NCIN], Hospital Episode Statistics [HES] and Office for National Statistics [ONS] datasets between 2000 and 2010 were linked, providing data on comorbidities, stage and date of death. A logistic regression model determined whether IBD was associated with an early [I/II] or late [III/IV] cancer. Cox regression analysis was used to examine survival differences between sporadic, UC- and CD-related cancers.A total of 234 009 patients with CRC were included, of whom 985 [0.4%] and 1922 [0.8%] had CD and UC, respectively. UC, but not CD, was associated with an earlier stage compared with sporadic cancers (odds ratio [OR] 0.88, 95% confidence interval [CI] 0.79 to 0.98, p = 0.02). CD had a significantly worse survival compared with sporadic patients for stage II [HR = 1.71, CI 1.26 to 2.31 p <0.005] and III [1.53, CI 1.20 to 1.96, p <0.005] cancer. UC patients were associated with worse survival compared with the sporadic group for both stage III [1.38, CI 1.17 to 1.63, p <0.0005] and IV [1.13, CI 1.01 to 1.28, p = 0.04] cancer. After excluding sporadic patients, UC was associated with improved survival compared with CD [0.62, CI 0.43 to 0.90, p = 0.01] for stage II cancer.Patients with IBD are diagnosed at an earlier stage but tend to have a worse survival compared with sporadic cases of CRC, in particular for nodal disease [stage III].Specifically, patients with CD-related CRC appear to fare worst in terms of survival compared with both the sporadic and UC groups.