Risk of Early Colorectal Cancers Needs to Be Considered in Inflammatory Bowel Disease Care

Background: Current guidelines recommend starting colorectal cancer (CRC) surveillance 8-10 years after inflammatory bowel disease (IBD) onset. Recent studies report that the incidence of CRC within 8-10 years of IBD onset (i.e., early CRC) ranges from 12 to 42%.

Aims: To describe the current prevalence of early CRC in a tertiary care center IBD cohort with CRC and to identify associated risk factors.

Methods: We performed a single-center observational study of IBD patients diagnosed with CRC from 2005 to 2015. We compared characteristics of patients with early CRC (diagnosis of CRC within 8 years of initial IBD onset) to those with CRC diagnosed later in their IBD course.

Results: Ninety-three patients met inclusion criteria. Eleven (11.8%) patients developed CRC within 8 years of initial IBD onset. On multivariable logistic regression, age greater than 28 at IBD onset (adjusted OR 12.0; 95% CI 2.30, 62.75) and tobacco use (adjusted OR 8.52; 95% CI 1.38, 52.82) were significant predictors of early CRC. A validation cohort confirmed calibration and discrimination of the model.

Conclusions: One out of every eight IBD patients with CRC developed their malignancy prior to the currently recommended timeframe for the initiation of surveillance colonoscopy. IBD onset at 28 years or older and tobacco use were identified as predictors of early CRC. Early CRC should be considered in discussions of cancer surveillance in this population. Prospective cohort studies are necessary to further analyze the impact of early CRC in IBD.