Isaac Tranter-Entwistle is a current SHO based at Christchurch Hospital. He has a keen interest in general surgery and surgical education. Previous research projects include evaluating vestibular function in people with vestibular schwannoma, optimising surgical ward round performance, and G.Adiacens infective endocarditis outcomes. When not at work he enjoys getting out and running the port hills.
Colorectal Cancer in the Canterbury Ulcerative Colitis Population: Implications for Screening
Aim Ulcerative colitis (UC) has long been established as a risk factor for developing colorectal cancer (CRC). Surveillance programs aim to identify pre-malignant lesions to facilitate improved treatment outcomes. Recent studies suggest that the risk of CRC in UC is lower than initially suggested. This study aims to characterise the risk of CRC in UC in a population-based cohort.
Methods A retrospective review of all UC patients in the Canterbury Inflammatory Bowel Disease Study was conducted. Demographic data and risk factors for dysplasia and CRC were recorded. Statistical analysis was undertaken using R, and standardized incidence ratios generated after comparison with the New Zealand population.
Results Five hundred and eighteen UC cases were analysed (46.3% female). Median follow up was 17.4 years. Colorectal neoplasia developed in 42 (8.1%) patients, 15 (2.9%) of whom had CRC. The mean age at CRC diagnosis was 64.4 years, and mean duration with UC before CRC 17.5 years (0-36.75 years). The total incidence rate was 1.44/1000 person years duration (CI 95% 0.81 – 2.39). When compared with the New Zealand population, the overall age adjusted standardised incidence ratio (SIR) was 1.86 (95% CI 1.12-3.08). Risk factors for any dysplasia included disease extent and male gender.
Conclusions This study of a well characterised population based cohort confirms the risk of CRC is higher in UC than the general population and is modified by a number of risk factors. While the magnitude of this risk appears less than historical estimates, colonoscopic surveillance in the UC population remains justified but should be tailored to the individual patient risk.