Rates of anal cancer are higher in patients with ulcerative colitis (UC) and Crohn disease (CD) compared with the general population, according to study results published in the Journal of Crohn’s and Colitis.
Researchers searched publication databases through November 2022 for studies evaluating the prevalence of anal cancer in inflammatory bowel disease (IBD).
A total of 6 studies comprising 78,711 patients and 518,969 person-years (py) of follow-up were included in the analysis of UC, and 6 studies comprising 56,845 patients and 671,899 py of follow-up were included in the CD analysis.
The incidence rates (IRs) of anal cancer were 10.2 (95% CI, 4.3-23.7) per 100,000 py (I2=66.6%) for UC and 7.7 (95% CI, 3.5-17.1) per 100,000 py (I2=73.3%) for CD.
For anal squamous cell carcinoma, rates differed significantly between patients with CD and UC, in which rates were high in the setting of UC (IR, 12.7; 95% CI, 3.9-41.6 per 100,000 py; I2=75.9%) and less so for CD (IR, 3.2; 95% CI, 1.3-7.8 per 100,000 py; I2=45.69%). However, the anal cancer rates were also elevated among the subset of patients with perianal CD (IR, 19.6; 95% CI, 12.2-31.6; I2=0.0%).
For high-risk human papillomavirus (HPV) and HPV16 infections, researchers did not perform a pooled analysis. In individual studies, the prevalence of HPV was reported as 25.7%-84.8%, and HPV16 was 10.9%-65% among patients with IBD. In a CD-specific study the rates of HPV and HPV16 were reported as 17.5% and 7.9%, respectively.
Similarly, no pooled analysis was performed for the outcome of abnormal anal histology and a wide range of rates were reported (range, 4%-72.9%).
This analysis may have been limited as little data about immunosuppression use was reported, making it infeasible to incorporate into the analyses.
“Patients with IBD seem to have a higher incidence of anal cancer than described in the general population,” the study authors noted. “The global incidence of anal cancer is higher in patients with UC than in CD, with the exception of perianal CD.”
“Patients with UC and perianal CD have inflammation in the rectum and/or anus as part of their disease and given this, are substantially different from other high-risk groups for anal cancer,” they added.
Albuquerque A, Cappello C, Stirrup O, Selinger CP. Anal high-risk human papillomavirus infection, squamous intraepithelial lesions and anal cancer in patients with inflammatory bowel disease: a systematic review and meta-analysis. J Crohns Colitis. Published online March 17, 2023. doi:10.1093/ecco-jcc/jjad045
This article originally appeared on Gastroenterology Advisor