Socioeconomic inequalities in interval colorectal cancer are explained by differences in faecal haemoglobin concentration and age: a register-based cohort study

Abstract

ObjectiveTo estimate the risk of interval colorectal cancer (CRC) in faecal immunochemical test (FIT) negative screening participants according to socioeconomic status.DesignIn this register-based study, first round FIT negative (<20 µg hb/g faeces) screening participants (biennial FIT, citizens aged 50–74) were followed to estimate interval CRC risk. Multivariate Cox proportional hazard regression models estimated HRs based on socioeconomic status defined by educational level and income. Models were adjusted for age, sex and FIT concentration.ResultsWe identified 829 (0.7‰) interval CRC in 1 160 902 individuals. Interval CRC was more common in lower socioeconomic strata with 0.7‰ for medium-long higher education compared with 1.0‰ for elementary school and 0.4‰ in the highest income quartile compared with 1.2‰ in the lowest. These differences did not translate into significant differences in HR in the multivariate analysis, as they were explained by FIT concentration and age. HR for interval CRC was 7.09 (95% CI) for FIT concentrations 11.9–19.8 µg hb/g faeces, and 3.37 (95% CI) for FIT between 7.2 and 11.8 compared with those <7.2. The HR rose with increasing age ranging from 2.06 (95% CI 1.45 to 2.93) to 7.60 (95% CI 5.63 to 10.25) compared with those under 55 years.ConclusionInterval CRC risk increased with decreasing income, heavily influenced by lower income individuals more often being older and having increased FIT concentrations. Individualising screening interval based on age and FIT result, may decrease interval CRC rates, reduce the social gradient and thereby increase the screening efficiency.

Factors associated with negative colonoscopy in participants with a positive faecal immunochemical test from the Danish Colorectal Cancer Screening Program – a population‐based study

“…This could be one explanation of our results and needs to be further explored, possibly by looking at interval cancers after negative colonoscopy, since this would then be higher for women. This has been explored in a study in which the authors looked at interval cancers following a negative FIT, and found that men had a higher risk of the event [32]. More nuance is needed to better understand this pattern, but the results support the notion that women with a positive FIT and a negative colonoscopy could have other, nonneoplastic explanations for their GI bleeding or missed colonoscopic findings.…”

El cáncer de intervalo, un reto aún por resolver

“…Las neoplasias en forma de lesión plana representan un desafío bien definido tanto para el endoscopista como para el patólogo (7) . En nuestro medio, la sobrecarga de las agendas, las dificultades en la preparación (ver Aponte y colaboradores) (8) , la prisa del endoscopista y la ausencia de tecnología adecuada en diferentes lugares son algunos de los muchos factores determinantes de la calidad en endoscopia diagnóstica y de tamización (9,10) . ción estratificada por riesgo, el uso de tecnologías con la cromoendoscopia y la inteligencia artificial podrán impactar esta situación (7) .…”