Evolution of socioeconomic inequalities in cancer incidence between 2006 and 2016 in France: a population-based study.

Abstract

The existence of socioeconomic inequalities in cancer incidence is now well established and their reduction is a priority in many countries. This study aimed to measure the evolution of socioeconomic inequalities in the incidence of the most common cancers in France, over an 11-year period. The study focused on 19 cancer entities (16 solid tumors and 3 hematological malignancies). Data are obtained from the French Network of Cancer Registries, representing 604 205 cancer cases. Each patient address was geolocalized and assigned to an IRIS, the smallest geographic unit in France. The French version of the European Deprivation Index was used to measure the level of deprivation in each IRIS. A generalized linear mixed model was used to account for the longitudinal nature of the data and to assess the evolution of socioeconomic inequalities. A significant evolution of the social gradient of incidence over time was highlighted for five cancer entities and all entities combined. For lung cancer for both sexes and bladder cancer in men, more frequent in deprived areas, the social gradient in incidence tended to decrease over time. For breast cancer in women and lymphocytic leukemia in men, more frequent in affluent areas, the gap continues to widen. Cancer entities with large disparities continued to present social inequalities in incidence without exacerbation with time. The few temporal evolutions observed do not show a worsening of the social gradient of incidence to the disadvantage of the most deprived areas, but rather an increase in incidence that is greater in the most affluent areas.