Timing of Thiopurine or Anti-TNF Initiation Is Associated with the Risk of Major Abdominal Surgery in Crohn's Disease: A Retrospective Cohort Study.

INTRODUCTION Early stages of Crohn's disease [CD] are predominantly inflammatory and early treatment could be useful to change the natural history of CD. We aimed to evaluate the impact of early treatment in our cohort of CD patients. METHODS We retrospectively reviewed clinical records of all CD patients at our centre who have received immunomodulators. Time from diagnosis to first CD-related major abdominal surgery or end of follow-up was considered. Dates of diagnosis, of starting immunomodulators (thiopurines / anti-tumour necrosis factor [TNF]), and of the first CD-related surgery when appropriate were collected. RESULTS Of 422 patients who received thiopurines, 189 operated patients started thiopurines after a median of 117 months (interquartile range [IQR] 44-196) since diagnosis; non-operated patients, after a median of 30 months [IQR 6-128], p < 0,005. Odds ratio [OR] for surgery was 1.006 (95% confidence interval [CI]1.004-1008) for each month of delay in starting thiopurines. Among 272 patients who received anti-TNFs, 137 operated patients started anti-TNFs after a median of 166 months [IQR 90-233] since diagnosis; non-operated patients after a median of 59 months [IQR 14-162]; p < 0,005. OR for surgery was 1.008 [95% CI 1.005-1.010] for each month of delay in starting anti-TNFs. Among 467 patients who received thiopurines and/or anti-TNF, 210 operated patients started any immunomodulator after a median of 120 months [IQR 48-197] since diagnosis and non-operated patients after a median of 30 months [IQR 6-126], p < 0,005. OR for surgery was 1.008 [95% CI 1.005-1.010] for each month of delay in starting immunomodulators. CONCLUSIONS In our experience, time between diagnosis and thiopurine or anti-TNF initiation was associated with the risk of major abdominal surgery in Crohn's disease.