P0287 Mild Crohn´s Disease is associated with a low, but not negligible, rate of progression, over a 5-year follow-up period

Background

Currently, most studies aim to identify predictive factors for complicated phenotype in Crohn’s disease (CD). However, it is equally important to identify factors associated with a mild disease course, thereby avoiding unnecessary exposure of patients to the potential risks of medication.

Methods

This was a retrospective cohort study of incident CD cases between February 2015 and August 2023. Mild CD was defined as: 1) absence or minimal symptoms at diagnosis, 2) absence of deep ulcers on colonoscopy, 3) absence of complications (strictures, fistula, perianal disease), and/or 4) no need for surgery within three months of diagnosis. A composite outcome was defined by the need of steroids, therapeutic escalation, surgery, progression to fistulizing/penetrating disease, or perianal disease. Survival analysis was performed.

Results

We included 40 patients (55% male; median age of 44 years, IQR [34-56]), with a median follow-up of 63 months, IQR [35–111]. According to Montreal classification the majority were A2 (55%) with terminal ileum involvement (L1 72.5%, of which 80% had <10 cm of ileal involvement, L2 20%, L3 7.5%). At diagnosis, 55% started on 5-ASA, 35% oral budesonide, and 10% did not receive any treatment. The composite outcome occurred in 22.5% of cases (9/40), with a median time until the event of 30 months IQR [6.5-70]: perianal disease in 0.03% (1/40), development of stricturing phenotype in 0.03% (1/40), need for steroids in 17.5% (7/40) and need to escalate therapy also in 17.5% (7/40) patients.

Characteristics at baseline were not different between those who developed the composite outcome. Shorter ideal disease showed a trend toward a lower rate of disease progression (16%vs 23%, p=0.09) (table 1). In a multivariate cox regression, none of these variables were independent predictors of the need of corticotherapy, escalation of therapy or the development of the composite outcome.

Conclusion

Only a minority of patients with mild CD had disease progression, which was generally indolent. No factors associated with worse outcomes were identified in our cohort. Mild CD appears to represent a distinct phenotype that warrants further investigation to better characterize its disease course.