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

The 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.