Declining Risk of Colorectal Cancer in Ulcerative Colitis
Declining Risk of Colorectal Cancer in Ulcerative Colitis
Background Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer (CRC); however, the magnitude of this effect is open to debate.
Aim To assess the risk of CRC in UC patients by systematic review and meta-analysis.
Methods A systematic literature search was performed up to November 2013. We selected studies describing the incidence and prevalence of CRC in patients with UC. Articles were assessed for quality using the Newcastle-Ottawa Scale. Cumulative incidence and incidence rates of CRC were combined and analysed using the generic inverse variance method. Sub-analyses were performed to identify factors associated with an increased risk of developing CRC.
Results A total of 81 studies (181 923 patients) met the inclusion criteria. The incidence rate of CRC in patients with UC was 1.58 per 1000 patient-years (py) [95% confidence interval (CI), 1.39–1.76]. Results were heterogeneous (I=81–89%). The incidence rate was 4.02/1000 py (95%CI = 2.74–5.31) in studies that only included patients with extensive colitis, and 1.24/1000 py (95%CI = 1.01–1.47) in population-based studies. The incidence rate was 0.91/1000 py (95%CI = 0.61–1.2) in the first decade of disease, 4.07/1000 py (95%CI = 2.58–5.56) in the second, and 4.55/1000 py (95%CI = 2.64–6.46) in the third. The incidence rate decreased from 4.29/1000 py in the studies published in the 1950s to 1.21/1000 py in studies published in the last decade.
Conclusions The risk of patients with ulcerative colitis developing colorectal cancer has decreased steadily over the last six decades, but the extent and duration of the disease increase this risk.
The inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease have been associated with an increased risk of developing colorectal cancer (CRC), probably caused by long-standing chronic inflammation. However, the magnitude of this effect remains open to debate. In, Eaden et al. published a landmark meta-analysis, reporting that the cumulative risk of CRC in patients with UC was 2% at 10 years, 8% at 20 years and 18% at 30 years. This meta-analysis and other studies showed that the risk of developing CRC in UC patients is increased by specific factors, such as disease duration, extensive mucosal involvement, concomitant primary sclerosing cholangitis, a family history of CRC and early onset of UC. These results were the basis for the current guidelines on endoscopic surveillance of CRC in UC patients.
However, recent studies have reported the incidence of CRC to be considerably lower. The aim of the present systematic review and meta-analysis was to update the estimation of the incidence of CRC in patients with UC.
Abstract and Introduction
Abstract
Background Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer (CRC); however, the magnitude of this effect is open to debate.
Aim To assess the risk of CRC in UC patients by systematic review and meta-analysis.
Methods A systematic literature search was performed up to November 2013. We selected studies describing the incidence and prevalence of CRC in patients with UC. Articles were assessed for quality using the Newcastle-Ottawa Scale. Cumulative incidence and incidence rates of CRC were combined and analysed using the generic inverse variance method. Sub-analyses were performed to identify factors associated with an increased risk of developing CRC.
Results A total of 81 studies (181 923 patients) met the inclusion criteria. The incidence rate of CRC in patients with UC was 1.58 per 1000 patient-years (py) [95% confidence interval (CI), 1.39–1.76]. Results were heterogeneous (I=81–89%). The incidence rate was 4.02/1000 py (95%CI = 2.74–5.31) in studies that only included patients with extensive colitis, and 1.24/1000 py (95%CI = 1.01–1.47) in population-based studies. The incidence rate was 0.91/1000 py (95%CI = 0.61–1.2) in the first decade of disease, 4.07/1000 py (95%CI = 2.58–5.56) in the second, and 4.55/1000 py (95%CI = 2.64–6.46) in the third. The incidence rate decreased from 4.29/1000 py in the studies published in the 1950s to 1.21/1000 py in studies published in the last decade.
Conclusions The risk of patients with ulcerative colitis developing colorectal cancer has decreased steadily over the last six decades, but the extent and duration of the disease increase this risk.
Introduction
The inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease have been associated with an increased risk of developing colorectal cancer (CRC), probably caused by long-standing chronic inflammation. However, the magnitude of this effect remains open to debate. In, Eaden et al. published a landmark meta-analysis, reporting that the cumulative risk of CRC in patients with UC was 2% at 10 years, 8% at 20 years and 18% at 30 years. This meta-analysis and other studies showed that the risk of developing CRC in UC patients is increased by specific factors, such as disease duration, extensive mucosal involvement, concomitant primary sclerosing cholangitis, a family history of CRC and early onset of UC. These results were the basis for the current guidelines on endoscopic surveillance of CRC in UC patients.
However, recent studies have reported the incidence of CRC to be considerably lower. The aim of the present systematic review and meta-analysis was to update the estimation of the incidence of CRC in patients with UC.