A suspicion of excess cases of pediatric cancers between 2013 and 2019 in children residing in Lyon was reported in January 2020 to the Auvergne-Rhône-Alpes Regional Health Agency (ARA) and to Public Health France ARA by the Center Léon Bérard (CLB). A joint investigation with the CLB was launched by Public Health France ARA based on the agency’s methodological guide. Two descriptive epidemiological studies, one based on data from the national register of childhood cancers (RNCE) and the other based on computerized files of children who were treated at the Institute of Hematology and pediatric oncology (IHOPe/CLB) in Lyon were carried out. The main objective of these two studies was to determine the possible existence of an excess incidence of certain pediatric cancers in the 1st and 4th arrondissements of Lyon. These two descriptive epidemiological studies concluded that there is a statistically significant excess incidence of cancers (all cancers combined) in children aged 0 to 14 years living in the 1st and 4th arrondissements of Lyon compared to the rest of Lyon. and in Caluire-et-Cuire (between 2010 and 2019 for the study on RNCE data, 2015-2019 for that of the CLB). The standardized incidence ratio (SIR) for all locations was 1.66 (confidence interval [IC] at 95%: 1.05 to 2.49) for the Public Health France study according to the RNCE and 1.58 (95% CI: 1.10 to 2.10) according to the study of the CLB. No excess incidence for a particular type of pediatric cancer was found. Over the period 2015-2019, there is also a slight excess incidence of pediatric cancers in Lyon compared to France (SIR=1.39; 95% CI: 1.20 to 1.59; CLB study). The analysis of existing environmental data on the study area did not make it possible to identify environmental exposures in the 1st and 4th arrondissements of Lyon different from those in the rest of the Lyon metropolitan area, and likely to be associated with pediatric cancers. Air pollution levels are relatively high but not higher than those in the rest of the metropolis. In addition, the types of cancer linked to air pollution (leukemia in particular) do not appear in excess in the 1st and 4th arrondissements. Subsequently, a descriptive survey was carried out among 10 families who requested the CLB, in order to look for a potential environmental exposure common to the cases which would not have been identified until then. This survey was carried out during the first quarter of 2022, in collaboration with oncologists and epidemiologists from CLB and IHOPe in Lyon. The study did not identify an exposure factor common to the cases identified, nor did it find a place regularly frequented by more than four children out of the nine respondents. The places frequented by three or four children were a school group, a municipal swimming pool and a public park. Within each of these three places visited, the children concerned had cancers of different clinical locations. In total, despite the moderate excess incidence of pediatric cancers in all locations combined, the absence of excess incidence for a particular type of cancer, the variety of anatomo-clinical forms of pediatric cancers occurring in the expected age groups, the absence of exposure to proven or plausible environmental risk factors common to all or the majority of cases present in the 1st and 4th arrondissements of Lyon and not in the rest of the metropolis, are all elements in favor of a probable random fluctuation of the pathology. These elements therefore argue against a spatio-temporal aggregate of pediatric cancers characterized in Lyon during the period 2010-2019, in the Croix-Rousse sector. The investigation was subject to regular monitoring with the group of parents concerned by this situation and health professionals. A three-stage restitution (administrations, caregivers, parents) was carried out in order to present the results, collect proposals and questions from stakeholders and outline avenues for the future. At the end of these restitutions, it was decided to carry out, three years after the publication of the report, an update of the incidence study of pediatric cancers in Lyon.
Author : Bénet Thomas, Fervers Béatrice, Praud Delphine, Pépin Philippe, Ndocko Kate-Mary, Saura Christine
Year of publication: 2024
Pages: 63 p.
Collection : Studies and surveys
