Rural-urban inequalities in detection rates of colorectal tumours in the population

Abstract

Background: Because few data are available on this topic, we investigated the influence of geographical determinants on colorectal adenoma detection and cancer incidence rates.

Methods: Between 1990 and 1999, 6220 Côte d'Or inhabitants (France) were first-diagnosed with a colorectal adenoma, and 2389 with an invasive adenocarcinoma. The impact of the rural-urban place of residence and of a physician location in municipalities on adenoma and cancer detection rates was studied using Poisson regression.

Results: World-standardized adenoma detection rate was significantly higher in urban areas (102 [95% CI: 97-107]) than in rural areas (78 [95% CI: 72-84]). The impact of the absence of physicians in municipalities was only found in rural areas. The detection rate ratio associated with the absence of a primary care physician was 0.70 [95% CI: 0.61-0.81], and the detection rate ratio associated with the absence of a gastroenterologist was 0.75 [95% CI: 0.64-0.89]. Colorectal cancer incidence rates were similar in urban and rural areas with only marginal variations related to physician location.

Conclusions: These results suggested a differential impact of geographical variables on the detection rates of colorectal adenomas and cancers in the population. Further studies are needed to examine socio-economic factors likely to be involved in these disparities.