Patients with ulcerative colitis have an increased risk of developing colorectal cancer.
However, the magnitude of this effect is open to debate.
Dr Castaño-Milla and colleagues from Spain assessed the risk of colorectal cancer in ulcerative colitis patients by systematic review and meta-analysis.
A systematic literature search was performed up to November 2013.
The research team selected studies describing the incidence and prevalence of colorectal cancer in patients with ulcerative colitis.
Articles were assessed for quality using the Newcastle-Ottawa Scale.
|The incidence rate of colorectal cancer in patients with ulcerative colitis was 1.6 per 1000 patient-years|
|Alimentary Pharmacology & Therapeutics|
Cumulative incidence and incidence rates of colorectal cancer were combined and analyzed using the generic inverse variance method.
The researchers performed sub-analyses to identify factors associated with an increased risk of developing colorectal cancer.
The team noted that a total of 81 studies met the inclusion criteria.
The incidence rate of colorectal cancer in patients with ulcerative colitis was 1.6 per 1000 patient-years.
The team found that the incidence rate was 4 per 1000 patient years in studies that only included patients with extensive colitis, and 1.2 per 1000 patients years in population-based studies.
The incidence rate was 0.9 per 1000 patient years in the first decade of disease, 4 per 1000 patients years in the second, and 4.6 per 1000 patient years in the third.
The research team found that the incidence rate decreased from 4.3 per 1000 patient years in the studies published in the 1950s to 1.2 per 1000 patient years in studies published in the last decade.
Dr Castaño-Milla's team concludes, "The risk of patients with ulcerative colitis developing colorectal cancer has decreased steadily over the last 6 decades, but the extent and duration of the disease increase this risk."