Risk of Anorectal Cancer Associated with Benign Anal Inflammatory Diseases: A Retrospective Matched Cohort Study

Abstract

Purpose: The purpose of our study was to evaluate the relationship between benign anal inflammatory diseases and anorectal cancer and assess its risk factors. Methods: A retrospective matched cohort study was conducted that included data from 2002 to 2013. The National Health Insurance Service National Sample Cohort data from 2002 to 2013 was used for the study. Of a total study population of 143,884 individuals, 28,110 individuals with anal fissures were assigned to the case group, while 115,774 individuals without anal fissures were assigned to the control group based on the 1:4 propensity score matching age, sex, and year (case: diagnosed year, control: health service received year). Results: The risk of anorectal cancer was higher in the case group (hazard ratio [HR]: 1.95, 95% confidence interval [CI]: 1.51–2.53) compared to the control group. After grouping anorectal cancers into anal cancer and rectal cancer, the risk remained higher in the case group (anal cancer HR: 2.79, 95% CI: 1.48–5.27; rectal cancer HR: 1.82, 95% CI; 1.37–2.42). The case group was further categorized into patients with fissures and patients with fistulas; patients with fissures showed a higher risk of developing anorectal cancer than patients with fistulas (HR: 2.05, 95% CI: 1.53–2.73 vs. HR: 1.73, 95% CI: 1.13–2.66). Study participants in their 30s and 40s had a 4.19- and 7.39-times higher risk of anorectal cancer compared to those in the higher age groups (0.64–1.84), while patients who did not have inflammatory bowel disease (IBD) had a higher risk of developing anorectal cancer (HR: 2.09, 95% CI: 1.56–2.80). Conclusions and Relevance: Patients with anal fistulas or fissures have an increased risk of being diagnosed with anorectal cancer, especially at a young age and even without IBD.

Analysis of definitive chemo-radiation outcomes in anal cancer: insights from a tertiary cancer center in the MENA Region

“…Another trial had explored the risk of anal squamous cell cancer in patients with anal fistulas and fissures. They demonstrated increased risk of cancer in those patients even without presence of irritable bowel disease ( 21 ). However, these series did not explore the influence of non-oncologic resection on disease outcomes.…”

Secondary anal fissures: a pain in the a**

“…Additional risk factors include smoking, genital warts and a history of receptive anal sexual intercourse (26,64,65). Multiple studies report that benign anorectal conditions such as anal fissures or fistulas are associated with an increased risk of anal cancer as well (65)(66)(67). HPV vaccination is expected to be the long-term solution to prevention of SCCA, but the impact will not be seen for decades (64).…”