Initial Treatment Failure as a Predictor of Proximal Extension in Patients with Newly Diagnosed Limited Ulcerative...

Patients with ulcerative colitis (UC) frequently experience proximal extension during their disease course.

We examined whether initial treatment failure affects proximal extension in limited UC.

This retrospective cohort study comprised patients who were newly diagnosed with limited UC between April 2006 and March 2015. Initial treatment failure was defined as either no remission within 3 months of onset (no remission group) or remission followed by relapse within 3 months (early relapse group). Patients who maintained remission for > 3 months were included in the initial treatment success group. The primary outcome was the incidence of proximal extension. Secondary outcomes included colectomy, hospitalization, and refractoriness to medication. Propensity score matching (PSM) was performed to adjust for baseline differences.

Of 229 eligible patients (median follow-up, 9.6 years), 68 (29.7%) developed proximal extension. Before PSM, initial treatment failure was significantly associated with proximal extension, and this association remained after PSM. In the overall cohort, multivariable Cox analysis confirmed initial treatment failure as an independent risk factor for proximal extension (adjusted hazard ratio 3.2; 95% confidence interval 1.9-5.3). The hospitalization rate was significantly higher in the initial treatment failure group than in the initial treatment success group after PSM.

Initial treatment failure is an independent prognostic factor for proximal extension in patients with limited UC and is associated with worse long-term outcomes. Careful monitoring and early therapeutic strategies may be warranted for patients with initial treatment failure.