Characteristics of Interval Colorectal Cancer: A Canadian Retrospective Population-Level Analysis from Newfoundland and Labrador

Abstract

Interval colorectal cancers (I-CRCs) arise during the interval time period between scheduled colonoscopies. Predicting which patients are at risk of I-CRCs remains an elusive undertaking, but evidence would suggest that most I-CRCs arise from lesions missed on index endoscopy. The procedural factors that lead to missed lesions are numerous and lack consensus in the literature. In Canada, the province of Newfoundland and Labrador has the highest incidence of CRCs. In this study our aim was to examine I-CRCs (3–60 months after last colonoscopy) in NL through a population-level analysis covering 67% of the province from 2001–2018. We estimated the I-CRC rate to be up to 9.3%. Median age of I-CRC diagnosis was 67.1 years with an interval time of 2.9 years. About 57% of these tumors occurred proximal to the splenic flexure, with 53% presenting as local disease. No temporal differences were observed in interval time or tumor distribution. On univariate and multivariable logistical regression, risk of right-sided I-CRC did not correlate to the index colonoscopy indication, bowel preparation quality, size of largest polyp removed, colonoscopy completion rate, or stage at presentation. Improvements in synoptic reporting utilization and national registries are needed to identity risk factors and reduce I-CRC frequency.

El cáncer de intervalo, un reto aún por resolver

“…Por ello, el Grupo de Trabajo de Expertos en cáncer colorrectal de intervalo del Comité de Detección de Cáncer Colorrectal de la Organización Mundial de Endoscopia (OME) (1,2) la ha definido como el cáncer después de un examen o prueba de detección colorrectal en el que no se detecta cáncer y antes de la fecha del siguiente examen recomendado, y actualmente se usa indiscriminadamente para describir cánceres del tracto gastrointestinal que se diagnostican durante el intervalo entre un estudio endoscópico informado como normal y el posterior examen fijado como de seguimiento. La proporción de cáncer de intervalo para cáncer gástrico es del 9,4% (intervalo de confianza [IC] del 95%: 5,7-13,1%) (3) , con una tasa ideal menor del 5% según la OME; la tasa de incidencia del cáncer de intervalo para el cáncer colorrectal es controvertida: varía entre 5,25% y 9,3% (4,5) . Su importancia tiene implicaciones diagnósticas, terapéuticas, éticas, legales y de salud pública, dada la carga de la enfermedad que representan las 2 neoplasias digestivas de mayor incidencia en nuestro medio.…”