Back to 2025 Posters
COMPARATIVE OUTCOMES OF FISTULA-ASSOCIATED AND NON-FISTULA ASSOCIATED ANORECTAL CANCERS IN CROHN'S DISEASE:
Imran Khan
*, Jessica Stockheim, Olga Lavryk, Benjamin L. Cohen, Stefan D. Holubar
Cleveland Clinic, Cleveland, OH
Introduction: Perianal fistulizing Crohn’s disease (PFCD)-associated anorectal and fistula cancers are rare but devastating complications of long-standing disease. The TOPClass consortium recently categorized them into PFCD-associated fistula cancers (directly involving fistulas) and non-fistula-associated anorectal cancers.
Methods: We retrospectively queried our prospectively maintained registry for Crohn’s disease patients with ICD codes for rectal or anal carcinomas and fistulas. Charts were manually reviewed, and patients were classified as fistula-associated if operative reports, MRI, or pathology confirmed cancer origin or communication with fistulas. All others were classified as non-fistula-associated. Data on Crohn’s disease, cancer, and treatment outcomes were collected. We hypothesized worse outcomes for fistula-associated cancers compared to those arising from native anorectal mucosa.
Results: A total of 63 patients were included. Stratification by histology was performed for meaningful comparison. We found 23 patients with PFCD-associated adenocarcinoma and 28 with non-fistula-associated adenocarcinoma. Median age at Crohn’s diagnosis was 25 years (IQR 19–36.5) in the fistula group vs. 28 years (IQR 19–36.5) in the non-fistula group (p=0.79). Complex fistulas were more common in the fistula group (75% vs. 0%, p=0.09). Persistent perineal sepsis and Crohn’s flare were more frequent in the fistula-associated group (p=0.04), while surveillance led to most diagnoses in the non-fistula group. High-risk histologic features (mucinous/signet cells) were more prevalent in the fistula group (73.9% vs. 32.1%, p=0.004). No differences were observed in biologic use (p=0.42) or neoadjuvant treatment (p=0.71). Pelvic exenteration was more common in the fistula group (13.6% vs. 0%, p=0.08), and positive margins were more frequent (47.6% vs. 25%, p=0.17). Postoperative complications and readmission rates were similar.
Table 1 Five-year overall survival (OS; hazard ratio [HR] 1.58, 95% confidence interval [CI] 0.82–5.96, p=0.11) and recurrence-free survival (RFS; HR 1.37, 95% CI 0.11–1.46, p=0.17) were comparable.
Figure 1 and 2.For squamous cell carcinoma (SCC), 8 patients had fistula-associated SCC, and 4 had non-fistula SCC.
Table 2 More advanced tumors (T3–T4) occurred in the fistula-associated group, but 5-year OS (HR 0.72, CI 0.10–2.79, p=0.47) and RFS (HR 0.18, CI 0.04–12.39, p=0.86) were similar.
Figure 3 and 4 All fistula-associated cases required multidisciplinary teams (colorectal, urology, plastics).
Conclusion: Our experience shows comparable outcomes for fistula-associated and non-fistula-associated anorectal cancers in Crohn’s disease regarding postoperative complications, OS, and RFS. Multidisciplinary management is crucial for optimal outcomes.
Back to 2025 Posters
