Background: Data on clinical characteristics of patients with inflammatory bowel disease (IBD)-related colorectal cancer (CRC) are scarce and mainly originate from tertiary referral centres. We studied patient and disease characteristics of IBD-related CRC in a nationwide IBD cohort in general hospitals. Main outcome parameters were time to develop CRC, and factors associated with early CRC development.
Methods: All IBD patients diagnosed with CRC between 1 January 1990 and 1 July 2006 were identified using a nationwide automated pathology database (PALGA). Patient charts were assessed to confirm diagnosis and collect clinical data. Early CRC was defined as CRC diagnosed less than 8 years after IBD diagnosis. Statistical analysis was performed using descriptive statistics, independent t tests, binary logistic regression and Cox-regression analysis.
Results: Diagnosis of IBD-related CRC was confirmed in 251 patients (171 ulcerative colitis, 77 Crohn's disease, 3 unclassified colitis), 161 males (64 %). Median time from IBD diagnosis to CRC diagnosis was 12 years (IQR 4-20); 89 patients (35 %) developed early CRC. Type of IBD, gender, concomitant PSC, pseudopolyps, extent of inflammation, and medication use were not related to early CRC (p > 0.05). IBD diagnosis at older age (HR for 10 years older age 2.25; 95 % CI 1.92-2.63) was related to early CRC. Twenty-three patients (12 %) had been included in a surveillance programme prior to CRC diagnosis. Patients in the surveillance group had a significantly better tumor stage (p = 0.004).
Conclusions: We emphasize the problem of a high proportion of IBD-associated CRCs developing before the recommended start of surveillance. Therefore, we suggest that older age at IBD onset could be an additional factor to start surveillance in IBD patients.