Survival after inflammatory bowel disease-associated colorectal cancer in the Colon Cancer Family Registry

AIM: To investigate the survival of individuals with colorectal cancer (CRC) with inflammatory bowel disease (IBD-associated CRC) compared to that of individuals without IBD diagnosed with CRC. METHODS: Epidemiologic, clinical, and follow-up data were obtained from the Colon Cancer Family Registry (Colon CFR). IBD-associated cases were identified from self-report of physician diagnosis. For a subset of participants, medical records were examined to confirm self-report of IBD. Cox proportional hazards regression was applied to estimate adjusted hazard ratios (aHR) and 95%CI of mortality, comparing IBD-associated to non-IBD-associated CRC, adjusted for age at CRC diagnosis, sex, Colon CFR phase, and number of prior endoscopies. Following imputation to complete CRC stage information, adjustment for CRC stage was examined. RESULTS: A total of 7202 CRC cases, including 250 cases of IBD-associated CRC, were analyzed. Over a twelve year follow-up period following CRC diagnosis, 2013 and 74 deaths occurred among non-IBD associated CRC and IBD-associated CRC patients, respectively. The difference in survival between IBD-associated and non-IBD CRC cases was not statistically significant (aHR = 1.08; 95%CI: 0.85-1.36). However, the assumption of proportional hazards necessary for valid inference from Cox regression was not met over the entire follow-up period, and we therefore limited analyses to within five years after CRC diagnosis when the assumption of proportional hazards was met. Over this period, there was evidence of worse prognosis for IBD-associated CRC (aHR = 1.36; 95%CI: 1.05-1.76). Results were similar when adjusted for CRC stage, or restricted to IBD confirmed in medical records. CONCLUSION: These results support the hypothesis that IBD-associated CRC has a worse prognosis than non-IBD-associated CRC.

Development and validation of a registry-based definition of eosinophilic esophagitis in Denmark

AIM:To develop and validate a case definition of eosinophilic esophagitis(EoE) in the linked Danish health registries.METHODS:For case definition development,we queried the Danish medical registries from 2006-2007 to identify candidate cases of EoE in Northern Denmark.All International Classification of Diseases-10(ICD-10) and prescription codes were obtained,and archived pathology slides were obtained and re-reviewed to determine case status.We used an iterative process to select inclusion/exclusion codes,refine the case definition,and optimize sensitivity and specificity.We then re-queried the registries from 2008-2009 to yield a validation set.The case definition algorithm was applied,and sensitivity and specificity were calculated.RESULTS:Of the 51 and 49 candidate cases identified in both the development and validation sets,21 and 24 had EoE,respectively.Characteristics of EoE cases in the development set [mean age 35 years;76% male;86% dysphagia;103 eosinophils per high-power field(eos/hpf)] were similar to those in the validation set(mean age 42 years;83% male;67% dysphagia;77 eos/hpf).Re-review of archived slides confirmed that the pathology coding for esophageal eosinophilia was correct in greater than 90% of cases.Two registrybased case algorithms based on pathology,ICD-10,and pharmacy codes were successfully generated in the development set,one that was sensitive(90%) and one that was specific(97%).When these algorithms were applied to the validation set,they remained sensitive(88%) and specific(96%).CONCLUSION:Two registry-based definitions,one highly sensitive and one highly specific,were developed and validated for the linked Danish national health databases,making future population-based studies feasible.