Impact of socio-economic environment on incidence of primary liver cancer in France between 2006 and 2016.

BACKGROUND AND AIMS: To measure the impact of socio-economic environment on the incidence of hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). METHOD: The study used data from the French Network of Cancer Registries (FRANCIM) between 2006 and 2016. Classification of patients into HCC and iCCA was performed according to the topographical and morphological codes of the 3rd edition of the International Classification of Diseases for Oncology. Patient addresses were geolocalized and assigned to an IRIS, the smallest French geographic unit. Socio-economic environment was assessed by the European Deprivation Index (EDI). Sex- and age-standardized incidence rates with 95% confidence intervals (CI) were estimated per 100 000 inhabitants, by national quintiles, for each IRIS, sex and age group. Quintile 1 (Q1) characterized the most affluent areas. A Poisson regression was performed to model the impact of deprivation. RESULTS: We included 22 249 cases (79.64% HCC, 16.97% iCCA). Incidence rates were 11.46 and 2.39 per 100 000 person-years for HCC and iCCA, respectively. There was an over-incidence of HCC in quintiles 2, 3, 4 and 5 compared to quintile 1: Q1 10.28 [9.9-10.66] per 100 000 person-years, Q2 11.43 [10.48-12.47] (p < .0001), Q3 11.81 [10.82-12.89] (p < .0001), Q4 12.26 [11.25-13.37] (p < .001) and Q5 11.53 [10.57-12.57] (p < .0001). By contrast, there was no difference for iCCa. Deprivation was significantly associated with HCC in men (p = .0018) and women (p = .0009), but not with iCCA (p = .7407). CONCLUSION: The incidence of HCC is related to socio-economic environment, unlike iCCA. HCC and iCCA should be studied separately in epidemiological studies.

Cancer Survival and Travel Time to Nearest Reference Care Center for 10 Cancer Sites: An Analysis of 21 French Cancer Registries.

BACKGROUND: The impact of several non-clinical factors on cancer survival is poorly understood. The aim of this study was to investigate the influence of travel time to the nearest referral center on survival of patients with cancer. PATIENTS AND METHODS: The study used data from the French Network of Cancer Registries that combines all the French population-based cancer registries. For this study, we included the 10 most common solid invasive cancer sites in France between 1 January 2013 and 31 December 2015, representing 160,634 cases. Net survival was measured and estimated using flexible parametric survival models. Flexible excess mortality modelling was performed to investigate the association between travel time to the nearest referral center and patient survival. To allow the most flexible effects, restricted cubic splines were used to investigate the influence of travel times to the nearest cancer center on excess hazard ratio. RESULTS: Among the 1-year and 5-year net survival results, lower survival was observed for patients residing farthest from the referral center for half of the included cancer types. The remoteness gap in survival was estimated to be up to 10% at 5 years for skin melanoma in men and 7% for lung cancer in women. The pattern of the effect of travel time was highly different according to tumor type, being either linear, reverse U-shape, non-significant, or better for more remote patients. For some sites restricted cubic splines of the effect of travel time on excess mortality were observed with a higher excess risk ratio as travel time increased. CONCLUSIONS: For numerous cancer sites, our results reveal geographical inequalities, with remote patients experiencing a worse prognosis, aside from the notable exception of prostate cancer. Future studies should evaluate the remoteness gap in more detail with more explanatory factors.

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

OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

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

BACKGROUND: 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.

Socioeconomic environment and disparities in cancer survival for 19 solid tumor sites: An analysis of the French Network of Cancer Registries (FRANCIM) data.

Social inequalities are concerning along the cancer continuum. In France, social gradient in health is particularly marked but little is known about social gradient in cancer survival. We aimed to investigate the influence of socioeconomic environment on cancer survival, for all cancers reported in the French Network of Cancer Registries. We analyzed 189,657 solid tumors diagnosed between 2006 and 2009, recorded in 18 registries. The European Deprivation Index (EDI), an ecological index measuring relative poverty in small geographic areas, assessed social environment. The EDI was categorized into quintiles of the national distribution. One- and five-year age-standardized net survival (ASNS) were estimated for each solid tumor site and deprivation quintile, among men and among women. We found that 5-year ASNS was lower among patients living in the most deprived areas compared to those living in the least deprived ones for 14/16 cancers among men and 16/18 cancers among women. The extent of cancer survival disparities according to deprivation varied substantially across the cancer sites. The reduction in ASNS between the least and the most deprived quintile reached 34% for liver cancer among men and 59% for bile duct cancer among women. For pancreas, stomach and esophagus cancer (among men), and ovary and stomach cancer (among women), deprivation gaps were larger at 1-year than 5-year survival. In conclusion, survival was worse in the most deprived areas for almost all cancers. Our results from population-based cancer registries data highlight the need for implementing actions to reduce social inequalities in cancer survival in France.

Tobacco-attributable burden of cancer according to socioeconomic position in France.

Smoking is a major preventable cause of cancers and is increasingly concentrated among the most deprived individuals leading to increasing socioeconomic inequalities in the incidence of cancers linked to smoking. We aimed to estimate the tobacco-attributable cancer burden according to socioeconomic position in France. The analysis was restricted to cancer sites for which tobacco smoking was recognized as a risk factor. Cancer cases by sex, age group and European Deprivation Index (EDI) among people aged 30-74 between 2006 and 2009 were obtained from cancer registries covering ∼20% of the French population. The tobacco-attributable burden of cancer according to EDI was estimated applying the population attributable fraction (PAF) computed with the Peto-Lopez method. The PAF increased from 56% in the least deprived EDI quintile to 70% in the most deprived EDI quintile among men and from 26% to 38% among women. In total, 28% of the excess cancer cases in the four most deprived EDI quintiles in men and 43% in women could be prevented if smoking in these 4 EDI quintiles was similar to that of the least deprived EDI quintile. A substantial smoking-attributable burden of cancer by socioeconomic position was observed in France. The results highlight the need for policies reducing tobacco consumption. More comprehensive interventions integrating the various dimensions of health determinants and proportionate according to socioeconomic position may essentially contribute to the reduction of socioeconomic inequalities in cancer.

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.

Neighborhood deprivation and risk of head and neck cancer: A multilevel analysis from France.

BACKGROUND: While it is known that cancer risk is related to area-level socioeconomic status, the extent to which these inequalities are explained by contextual effects is poorly documented especially for head and neck cancer. METHODS: A case-control study, ICARE, included 2415 head and neck cancer cases and 3555 controls recruited between 2001 and 2007 from 10 French regions retrieved from a general cancer registry. Individual socioeconomic status was assessed using marital status, highest educational level and occupational social class. Area-level socioeconomic status was assessed using the French version of the European Deprivation Index (EDI). The relationship between both individual and area-based socioeconomic level and the risk of head and neck cancer was assessed by multilevel analyses. RESULTS: A higher risk for head and neck cancer was found in divorced compared with married individuals (OR=2.14, 95% CI=1.78-2.57), for individuals with a basic school-leaving qualification compared with those with higher education (OR=4.55 95% CI=3.72-5.57), for manual workers compared with managers (OR=4.91, 95% CI=3.92-6.15) and for individuals living in the most deprived areas compared with those living in the most affluent ones (OR=1.98, 95% CI=1.64-2.41). The influence of area-level socioeconomic status measured by EDI remained after controlling for individual socioeconomic characteristics (OR=1.51; 95% confidence interval: 1.23-1.85, p-value=0.0003). CONCLUSIONS: The role of individual socioeconomic status in the risk of head and neck cancer is undeniable, although contextual effects of deprived areas also increase the susceptibility of individuals developing the disease.

Correction of misclassification bias induced by the residential mobility in studies examining the link between socioeconomic environment and cancer incidence.

BACKGROUND: Many international ecological studies that examine the link between social environment and cancer incidence use a deprivation index based on the subjects' address at the time of diagnosis to evaluate socioeconomic status. Thus, social past details are ignored, which leads to misclassification bias in the estimations. The objectives of this study were to include the latency delay in such estimations and to observe the effects. METHODS: We adapted a previous methodology to correct estimates of the influence of socioeconomic environment on cancer incidence considering the latency delay in measuring socioeconomic status. We implemented this method using French data. We evaluated the misclassification due to social mobility with census data and corrected the relative risks. RESULTS: Inclusion of misclassification affected the values of relative risks, and the corrected values showed a greater departure from the value 1 than the uncorrected ones. For cancer of lung, colon-rectum, lips-mouth-pharynx, kidney and esophagus in men, the over incidence in the deprived categories was augmented by the correction. CONCLUSIONS: By not taking into account the latency period in measuring socioeconomic status, the burden of cancer associated with social inequality may be underestimated.

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

BACKGROUND: 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.