Risk of Childhood Cancer and Socio-economic Disparities: Results of the French Nationwide Study Geocap 2002-2010.

BACKGROUND: Socio-economic status is related to many life style and environmental factors, some of which have been suggested to influence the risk of childhood cancer. Studies requiring subject participation are usually hampered by selection of more educated parents. To prevent such bias, we used unselected nationwide Geographical Information System (GIS)-based registry data, to investigate the influence of socio-economic disparities on the risk of childhood cancer.

METHODS: The Geocap study included all French residents diagnosed with cancer aged up to 15 years over the period 2002-2010 (15 111 cases) and 45 000 contemporaneous controls representative of the childhood population. Area socio-economic characteristics used to calculate the European Deprivation Index (EDI) were based on census data collected on the fine scale of the Merged Islet for Statistical Information (IRIS).

RESULTS: Overall, the risk of acute lymphoblastic leukaemia (ALL) was lower in the most deprived quintile than in the other quintiles of EDI (ORQ5vs<Q5 0.80 (95% confidence interval (CI) 0.73, 0.88)). The odds ratio for all the other cancers taken together was close to the null (ORQ5vs<Q5 0.99 (95% CI 0.94, 1.04)).

CONCLUSION: Living in the most deprived areas was inversely associated with the risk of ALL in childhood. There was no indication that the risk of childhood cancer of any site could be increased by deprivation. Life style or environmental factors potentially underlying the association need further investigation.