P200 Risk of progression of preclinical ulcerative colitis

Abstract

Abstract Background The diagnosis of ulcerative colitis (UC) is usually established after the development of symptoms, but preclinical disease may be present even years before the final diagnosis. Around 25% of UC patients may show a proximal extension of the disease. The primary aim of the study was to define the main characteristics and the risk of progression of preclinical UC. Methods We performed a multicentric, retrospective study of all patients included in the colorectal cancer screening programme in 11 centres between 2009–2014. All subjects were initially assessed with a faecal occult blood test (OC-Sensor, Eiken Chemical Co., Tokyo, Japan) and, if this test was positive (cut-off 20 μg Hgb/g), a colonoscopy was performed. All patients were asymptomatic and had an incidental diagnosis of UC confirmed by histology during a screening colonoscopy. The main outcomes were the risk of developing symptomatic disease and proximal disease extension. A chi-square test was performed in order to assess the risk factors of proximal extension and symptomatic disease. Results During this period we performed 31 005 colonoscopies after 498 227 FIT. We included 79 patients with a new diagnosis of UC (age 58 years [IQR, 52–63], 37% non-smokers]). At baseline, disease extension was E1 in 32%, E2 in 33% and E3 in 35%. After a median follow-up of 29 months (IQR, 17–41), 76% received some treatment, and no patient showed proximal disease extension. In 45% (33% E3 and 12% E2) we observed a reduction of the disease extension. Among those subjects who were asymptomatic at diagnosis, 32% developed symptomatic disease after a median of 7.5 months (IQR, 1–14). Disease extent at diagnosis did not influence the risk of symptomatic disease during follow-up (p = 0.85). Those patients with left-sided or extensive UC were more frequently treated with mesalazine, systemic steroids or thiopurines, compared with those with proctitis (p = 0.001, 0.023 and 0.047, respectively). Conclusion Approximately one-third of patients with preclinical UC develop symptomatic disease, but there is no risk of proximal disease extension after 2 years of follow-up.