Thiopurine Therapy Reduces the Incidence of Colorectal Neoplasia in Patients with Ulcerative Colitis. Data from the ENEIDA Registry

Background and Aims: Patients with ulcerative colitis (UC) are at increased risk of developing colorectal cancer (CRC), but recent studies suggest a lower risk than previously reported. The aim was to evaluate the incidence of dysplasia, CRC and related risk factors in UC patients from a Spanish nationwide database. Methods: All UC patients were identified and retrospectively reviewed. Clinical–epidemiological data and the finding of dysplasia and/or CRC were collected. Results: A total of 831 UC patients were included. Twenty-six cases of CRC in 26 patients and 29 cases of high-grade dysplasia (HGD) in 24 patients were found, accounting for 55 diagnoses of advanced neoplasia (AN = CRC and/or HGD) in 45 patients (33% of them within the first 8 years after UC diagnosis). The cumulative risk of AN was 2, 5.3 and 14.7% at 10, 20 and 30 years, respectively. Concomitant primary sclerosing cholangitis (odds ratio [OR] 10.90; 95% confidence interval [CI] 3.75–31.76, p < 0.001), extensive UC (OR 2.10, 95% CI 1.01–4.38, p = 0.048), UC diagnosis at an older age (OR 2.23, 95% CI 1.03–4.83, p = 0.043) and appendectomy prior to UC diagnosis (OR 2.66, 95% CI 1.06–6.71, p = 0.038) were independent risk factors for AN. Use of thiopurines (OR 0.21, 95% CI 0.06–0.74, p = 0.015) and being in a surveillance colonoscopy programme (OR 0.33; 95% CI 0.16–0.67; p = 0.002) were independent protective factors for AN. Conclusions: The risk of AN among UC patients is lower than previously reported but steadily increases from the time of UC diagnosis. The widespread use of thiopurines may have influenced this reduced incidence of UC-related neoplasias.