Background: Early detection and advancement in therapy have successfully achieved a steady decrease in colorectal cancer (CRC) mortality over the last two decades. On the other hand, studies investigating mortality trends in inflammatory bowel disease-associated CRC (IBD-CRC) are scarce and inconclusive. We conducted a retrospective analysis aiming to identify differences between inpatient mortality trends in IBD-CRC vs non-IBD-CRC and possible contributing factors.

Methods: The National Inpatient Sample (NIS) database from 2006-2014 was queried to identify all patients admitted with a diagnosis of CRC. The main outcome was the prevalence and trend of mortality among IBD-CRC and non-IBD-CRC. The secondary outcome was the evaluation of predictors of inpatient mortality.

Results: A total of 1,190,759 weighted cases with the admission diagnosis of CRC were included in the study. Of which 10,997 (0.9%) had a co-diagnosis of IBD. The population with non-IBD-CRC had a statistically significant downward temporal trend in mortality (p < 0.001), while patients with IBD-CRC did not have any statistically significant temporal trend in inpatient mortality (p = 0.067). After subgroup analysis, patients with Crohn's disease-CRC had an upward temporal trend in mortality (p = 0.183) compared to patients with ulcerative colitis-CRC with a downward trend in mortality (p = 0.001). Sepsis resulted to be a stronger predictor of mortality for CD-CRC, while VTE for UC-CRC.

Conclusion: Multiples strategies established to prevent morbidity and mortality in CRC have been fruitful in non-IBD-CRC population, but have not been enough for IBD-CRC population to cause the same effect. Further strategies are needed to achieve a reduction in IBD-CRC mortality trend.