Does IBD Portend Worse Outcomes in Patients with Rectal Cancer? A Case-Matched Analysis
Authors: Alsughayer Ahmad , Grass Fabian , McKenna Nicholas P. , Petersen Molly , Mathis Kellie L. , Lightner Amy L. 
Published: August 2020

BACKGROUND:
Patients with IBD are at increased risk for developing colorectal cancer. However, overall survival and disease-free survival for rectal cancer alone in patients with IBD has not been reported.

OBJECTIVE:
This study aimed to determine overall survival and disease-free survival for patients with rectal cancer in IBD versus non-IBD cohorts.

DESIGN:
This is a retrospective cohort study.

SETTING:
This study was conducted at an IBD referral center.

PATIENTS:
All consecutive adult patients with IBD diagnosed with rectal cancer and at least 1 year of postsurgery follow-up were included and matched in a 1:2 fashion (age, sex, preoperative stage) with patients with rectal cancer who did not have IBD.

MAIN OUTCOMES MEASURES:
Five-year overall survival and disease-free survival, 30-day postoperative complication, readmission, reoperation, and mortality rates were measured.

METHODS:
Survival rates were calculated using Kaplan-Meier estimates. The association of risk factors and long-term outcomes was assessed using Cox proportion hazard models.

RESULTS:
A total of 107 study patients with IBD who had rectal cancer were matched to 215 control patients; preoperative stages were as follows: 31% with stage I, 19% with stage II, 40% with stage III, and 10% with stage IV. Differences were observed (IBD vs non-IBD) in neoadjuvant chemotherapy (33.6% vs 52.6%, p = 0.001) and preoperative radiotherapy (35.5% vs 53.5%, p = 0.003). Postoperative complication rates were similar. On surgical pathology, patients with IBD had more lymphovascular invasion (12.9% vs 5.6%, p = 0.04) and positive circumferential resection margins (5.4% vs 0.9%, p = 0.03). On multivariable analysis, the diagnosis of IBD did not significantly impact long-term mortality (HR, 0.91; 95% CI, 0.53–1.57; p = 0.73) or disease-free survival (HR, 1.36; 95% CI, 0.84–2.21; p = 0.22).

LIMITATIONS:
This study was limited by its retrospective design and the use of single-center data.

CONCLUSIONS:
Patients have rectal cancer with IBD and without IBD have similar long-term and disease-free survival, despite lower rates of neoadjuvant treatment and higher margin positivity in patients with IBD. See Video Abstract at http://links.lww.com/DCR/B271.

¿LA ENFERMEDAD INFLAMATORIA INTESTINAL ACARREA PEORES RESULTADOS EN PACIENTES CON CÁNCER RECTAL? UN ANÁLISIS DE CASOS-COINCIDENTES

ANTECEDENTES:

Los pacientes con enfermedad inflamatoria intestinal (EII) tienen un mayor riesgo de desarrollar cáncer colorrectal. Sin embargo, no se ha informado la supervivencia general y la supervivencia libre de enfermedad para el cáncer rectal solo en pacientes con EII.

OBJETIVO:

Determinar la supervivencia general y la supervivencia libre de enfermedad para pacientes con cáncer rectal en cohortes con EII versus sin EII.

DISEÑO:

Estudio de cohorte retrospectivo.

MARCO:

Centro de referencia para enfermedad inflamatoria intestinal.

PACIENTES:

todos los pacientes adultos con EII diagnosticados con cáncer rectal, consecutives, y al menos un año de seguimiento postoperatorio se incluyeron y se emparejaron de manera 1: 2 (edad, sexo, etapa preoperatoria) con pacientes con cáncer rectal sin EII.

MEDIDAS DE RESULTADO PRINCIPALES:

Se midieron la supervivencia general a cinco años y la supervivencia libre de enfermedad, complicaciones postoperatorias a los 30 días, reingreso, reoperación y tasas de mortalidad.

MÉTODOS:

Las tasas de supervivencia se calcularon utilizando estimaciones de Kaplan-Meier. La asociación de factores de riesgo y resultados a largo plazo se evaluó mediante modelos de riesgo de proporción de Cox.

RESULTADOS:

Un total de 107 pacientes con EII y cáncer rectal se compararon con 215 pacientes de control; las etapas preoperatorias fueron las siguientes: 31% de Etapa I, 19% de Etapa II, 40% de Etapa III y 10% de Etapa IV. Se observaron diferencias (EII versus no EII) en quimioterapia neoadyuvante (33.6% frente a 52.6%, p = 0.001) y radioterapia preoperatoria (35.5% frente a 53.5%, p = 0.003). Las tasas de complicaciones postoperatorias fueron similares. En la patología quirúrgica, los pacientes con EII tuvieron más invasión linfovascular (12.9% frente a 5.6%, p = 0.04) y márgenes de resección circunferencial positivos (5.4% frente a 0.9%, p = 0.03). En el análisis multivariable, el diagnóstico de EII no tuvo un impacto significativo en la mortalidad a largo plazo (HR 0.91; IC del 95%: 0.53-1.57, p = 0.73) o la supervivencia libre de enfermedad (HR 1.36; IC del 95%: 0.84-2.21, p = 0.22)

LIMITACIONES:

Diseño retrospectivo, centro único de datos.

CONCLUSIONES:

Los pacientes con EII y sin EII con cáncer rectal tienen una supervivencia similar a largo plazo y libre de enfermedad, a pesar de las tasas más bajas de tratamiento sneoadyuvante y un mayor margen positivo en pacientes con EII. Consulte Video Resumen en
http://links.lww.com/DCR/B271.