SOCIALE ASPECTEN
SOCIOECONOMIC POSITION, CANCER INCIDENCE AND STAGE AT DIAGNOSIS – A NATIONWIDE COHORT STUDY PROBLEEM- EN DOELSTELLING(EN) ONDERZOEKSPROJECT
Socioeconomic (SE) position is associated with cancer incidence, survival and mortality. However, the direction and magnitude of this relationship differs across cancer types, geographical regions and SE parameters. The aim of this study was to evaluate and characterize the associations between SE and sociodemographic (SD) indicators at individual level, and the risk of being diagnosed with different cancer types at the Belgian population level. Cancer stage being a major determinant for prognosis, a second aim was to explore the association between SE position and cancer stage availability and distribution.
ONDERZOEKSOPZET Individual level data of the 2001 census for persons aged 25 years or older, was linked to the nationwide Belgian Cancer Registry for diagnoses during 2004-2013. Three SE or SD parameters (education level, household composition and housing conditions) and six cancer types (lung cancer, colon cancer, rectum cancer, head and neck cancers, female breast cancer and malignant melanoma) were considered. Incidence rate ratios (IRR) were assessed through Poisson regression models and stage-specific analyses conducted through logistic regression models and reported as odds ratios (OR). Analyses included multivariable-adjusted models, incorporating age, region of residence and self-reported health at time of census and estimates were reported with 95% confidence interval [95%-CI].
RESULTATEN The study cohort encompassed almost seven million individuals. Deprived groups showed higher risks for lung and head and neck cancers, whereas an inverse relation was observed for female breast cancer and malignant melanoma (IRR for head and neck cancers in men for the lowest compared to the highest education was 1.31 [1.23-1.39] compared to 0.56 [0.51-0.61] for malignant melanoma). Typically, associations were more pronounced in men than in women (IRR for lung in men for the lowest compared to the highest education was 2.00 [1.93-2.06] compared to 1.63 [1.54-1.72] in women). Lower socioeconomic position was associated with reduced chances of being diagnosed with a known stage or early stage at diagnosis, with the strongest disparities in male lung cancer (OR for being diagnosed with unknown stage, low-comfort compared to high-comfort housing: 1.23[1.16-1.31]) and female breast cancer (OR for being diagnosed with advanced stage, low-comfort compared to high-comfort housing: 1.32[1.25-1.40]).
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