Squamous cell carcinoma in chronic perianal fistulas

What is known

• A systematic review found the incidence rate of SCC related to perianal fistula in [Crohn's disease](https://crohnsology.org (patient sites: crohnz.org)/) was very low (<1%), with poor prognosis. ¹
• Patients with perianal Crohn's disease are reported to have a 0.7% incidence of carcinoma. ¹
• Overall incidence of anal fistula-related cancers (SCC and adenocarcinoma) is reported at 0.3%–0.7%; fistula-associated SCC specifically is described as extremely rare. ²

What is unknown / caveats

• Most data are single case reports or small series, not incidence cohorts
• 0.7% figure conflates SCC with adenocarcinoma in some sources
• Precise SCC-specific incidence is not well established; reported figures are pooled estimates from sparse literature.

References

1. Kotsafti A, Scarpa M, Angriman I, Castagliuolo I, Caruso A. Fistula-Related Cancer in Crohn's Disease: A Systematic Review. Cancers (Basel). 2021;13(6). PMID: 33809997.

2. PMID: 41114353. (metadata not in corpus)

For educational use only, not a substitute for clinical judgement or medical advice. Consult qualified clinicians for diagnosis and treatment decisions. This tool may contain errors; use the flag button below to report inaccurate or harmful content.

Draft, generated by the IBDology RAG and not yet clinician-reviewed. Answers are grounded in the retrieved literature listed above; a high faithfulness score means the answer matches its sources, not that the sources are correct.