Socioeconomic status and site-specific cancer incidence, a Bayesian approach in a French Cancer Registries Network study

International audienceThe aim of this study was to identify and compare cancer sites whose incidence is influenced by social deprivation. The study population comprised 189 144 cases of cancer diagnosed between 2006 and 2009, recorded in member registries of the French Network of Cancer Registries. Social environment was assessed at an aggregate level using the European Deprivation Index. The association between incidence and socioeconomic status was assessed by a geographical Bayesian Poisson model enabling a reduction of the overall variability and smoothing of the relative risks by sharing information provided by multiple geographic units. For cancers of the stomach, liver, lips-mouth-pharynx, and lung, a higher incidence in deprived populations was found for both sexes as well as for cancers of the larynx, esophagus, pancreas, and bladder in men and cervical cancer in women. For melanoma, prostate, testis, ovarian, and breast cancer, a higher incidence was observed in affluent populations. The highest relative risks of the lowest social class compared with the highest social class were found for larynx [relative risk (RR) = 1.67 (1.43-1.95)], lips-mouth-pharynx [RR = 1.89 (1.72-2.07)], and lung cancer [RR = 1.59 (1.50-1.68)] in men and for cervix [RR = 1.62 (1.40-1.88)] and lips-mouth-pharynx [RR = 1.56 (1.30-1.86)] cancer in women. By estimating the burden of social deprivation on cancer incidence throughout France, this study enables us to measure the gains that could be achieved by implementing targeted prevention efforts

The respective parts of incidence and lethality in socioeconomic differences in cancer mortality. An analysis of the French network Cancer registries (FRANCIM) data

International audienceBACKGROUND:To determine relevant public health actions and to guide intervention priorities, it is of great importance to assess the relative contribution of incidence and lethality to social inequalities in cancer mortality.METHODS:The study population comprised 185,518 cases of cancer diagnosed between 2006 and 2009 recorded in the French registries. Survival was known for each patient (endpoint: 30/06/2013). Deprivation was assessed using the European Deprivation Index. We studied the influence of deprivation on mortality, incidence and lethality rates and quantified the respective proportions of incidence and lethality in social inequalities in mortality by calculating attributable deaths.RESULTS:For cancers with social inequalities both in incidence and lethality, excess mortality in deprived was mainly caused by social inequalities in incidence (e.g. men lung cancer: 87% of excess deaths in the deprived caused by inequalities in incidence). Proportions were more balanced for some cancer sites (e.g. cervical cancer: 56% incidence, 44% lethality). For cancer sites with a higher incidence in the least deprived (e.g. breast cancer), the excess-lethality in deprived leads entirely the higher mortality among the deprived.CONCLUSIONS:Most of the excess mortality in deprived is due to the excess incidence of tobacco-dependent cancers and the excess lethality of screenable cancers

Assessment of the ecological bias of seven aggregate social deprivation indices

International audienceAbstractBackgroundIn aggregate studies, ecological indices are used to study the influence of socioeconomic status on health. Their main limitation is ecological bias. This study assesses the misclassification of individual socioeconomic status in seven ecological indices.MethodsIndividual socioeconomic data for a random sample of 10,000 persons came from periodic health examinations conducted in 2006 in 11 French departments. Geographical data came from the 2007 census at the lowest geographical level available in France. The Receiver Operating Characteristics (ROC) curves, the areas under the curves (AUC) for each individual variable, and the distribution of deprived and non-deprived persons in quintiles of each aggregate score were analyzed.ResultsThe aggregate indices studied are quite good “proxies” for individual deprivation (AUC close to 0.7), and they have similar performance. The indices are more efficient at measuring individual income than education or occupational category and are suitable for measuring of deprivation but not affluence.ConclusionsThe study inventoried the aggregate indices available in France and evaluated their assessment of individual SES

Socioeconomic environment and cancer incidence: a French population-based study in Normandy.

International audienceBACKGROUND: The struggle against social inequalities is a priority for many international organizations. The objective of the study was to quantify the cancer burden related to social deprivation by identifying the cancer sites linked to socioeconomic status and measuring the proportion of cases associated with social deprivation. METHODS: The study population comprised 68 967 cases of cancer diagnosed between 1997 and 2009 in Normandy and collected by the local registries. The social environment was assessed at an aggregated level using the European Deprivation Index (EDI). The association between incidence and socioeconomic status was assessed by a Bayesian Poisson model and the excess of cases was calculated with the Population Attributable Fraction (PAF). RESULTS: For lung, lips-mouth-pharynx and unknown primary sites, a higher incidence in deprived was observed for both sexes. The same trend was observed in males for bladder, liver, esophagus, larynx, central nervous system and gall-bladder and in females for cervix uteri. The largest part of the incidence associated with deprivation was found for cancer of gall-bladder (30.1%), lips-mouth-pharynx (26.0%), larynx (23.2%) and esophagus (19.6%) in males and for unknown primary sites (18.0%) and lips-mouth-pharynx (12.7%) in females. For prostate cancer and melanoma in males, the sites where incidence increased with affluence, the part associated with affluence was respectively 9.6% and 14.0%. CONCLUSIONS: Beyond identifying cancer sites the most associated with social deprivation, this kind of study points to health care policies that could be undertaken to reduce social inequalities