Adverse Oncologic Outcomes of Adenocarcinoma of the Anal Canal in Patients With Crohn’s Disease

BACKGROUND Anal lesions in cases of Crohn's disease can give rise to adenocarcinoma of the anal canal; however, the oncologic outcomes in these patients have not yet been thoroughly investigated. OBJECTIVE This study aimed to clarify the influence of Crohn's disease on the oncologic outcomes in patients with adenocarcinoma of the anal canal. DESIGN This was a retrospective observational study from a prospectively collected database. SETTINGS The study was conducted at a single institution. PATIENTS This study included 102 patients with adenocarcinoma of the anal canal, including 34 (33.3%) with Crohn's disease-associated lesions and 68 (66.7%) with non-Crohn's disease-associated lesions. MAIN OUTCOME MEASURES Prognostic factors were detected using a Cox regression analysis, and the oncologic outcomes were calculated using the Kaplan-Meier method. RESULTS Crohn's disease-associated patients were significantly younger (45 vs 62 y; p < 0.001), had a high incidence of external/anal gland-type disease (61.8% vs 5.9%, p < 0.001) and had large tumors (7.1 ± 3.0 vs 4.7 ± 2.3 cm; p = 0.03) in comparison with non-Crohn's disease-associated patients. A Cox regression analysis showed that an advanced clinical T stage (T3 or T4; tumor size ≥5 cm) was an independent risk factor for 5-year local recurrence-free survival (HR = 3.49; p = 0.04), disease-free survival (HR = 2.82; p = 0.008), and overall survival (HR = 2.92; p = 0.006), and Crohn's disease association was an independent prognostic factor for local recurrence-free survival (HR = 2.29; p = 0.04) and overall survival (HR = 2.86; p = 0.04). The oncologic outcomes of patients who had the 2 abovementioned negative factors (cT3,4 Crohn's disease-associated patients) were significantly poorer than those of T3,4 non-Crohn's disease-associated patients (5-year local recurrence-free survival: 32.5% vs 70.4%, p = 0.001; disease-free survival: 15.9% vs 40.7%, p = 0.04; overall survival: 25.8% vs 71.0%, p = 0.007). LIMITATIONS This was a single-arm, retrospective study. CONCLUSIONS Significantly poorer oncologic outcomes were confirmed in Crohn's disease-associated patients with large tumors. Thus, it is important to perform careful surveillance of anal lesions in patients with Crohn's disease while taking these facts into consideration. See Video Abstract at http://links.lww.com/DCR/B449. RESULTADOS ONCOLGICOS ADVERSOS DEL ADENOCARCINOMA DEL CANAL ANAL EN PACIENTES CON ENFERMEDAD DE CROHN ANTECEDENTES:Las lesiones anales en casos de enfermedad de Crohn pueden dar lugar a un adenocarcinoma del canal anal; sin embargo, los resultados oncologicos en estos pacientes aun no se han investigado a fondo.OBJETIVOS:Este estudio tuvo como objetivo aclarar la influencia de la enfermedad de Crohn en los resultados oncologicos en pacientes con adenocarcinoma del canal anal.DISENO:Estudio observacional retrospectivo de una base de datos recopilada prospectivamente.ENTORNO CLINICO:El estudio se realizo en una sola institucion.PACIENTES:Este estudio incluyo 102 pacientes con adenocarcinoma del canal anal, incluidos 34 (33,3%) con lesiones asociadas a la enfermedad de Crohn y 68 (66,7%) con lesiones no asociadas a la enfermedad de Crohn.PRINCIPALES MEDIDAS DE VOLARACION:Los factores pronosticos se detectaron mediante un analisis de regresion de Cox y los resultados oncologicos se calcularon utilizando el metodo de Kaplan-Meier.RESULTADOS:Los pacientes asociados a la enfermedad de Crohn eran significativamente mas jovenes (45 versus a 62 anos, p