'Socioeconomic position and survival after cervical cancer: influence of cancer stage, comorbidity and smoking among Danish women diagnosed between 2005 and 2010

Background: In an attempt to decrease social disparities in cancer survival, it is important to consider the mechanisms by which socioeconomic position influences cancer prognosis. We aimed to investigate whether any associations between socioeconomic factors and survival after cervical cancer could be explained by socioeconomic differences in cancer stage, comorbidity, lifestyle factors or treatment. Methods: We identified 1961 cases of cervical cancer diagnosed between 2005 and 2010 in the Danish Gynaecological Cancer database, with information on prognostic factors, treatment and lifestyle. Age, vital status, comorbidity and socioeconomic data were obtained from nationwide administrative registers. Associations between socioeconomic indicators (education, income and cohabitation status) and mortality by all causes were analysed in Cox regression models with inclusion of possible mediators. Median follow-up time was 3.0 years (0.01-7.0). Results: All cause mortality was higher in women with shorter rather than longer education (hazard ratio (HR), 1.46; 1.20-1.77), among those with lower rather than higher income (HR, 1.32; 1.07-1.63) and among women aged <60 years without a partner rather than those who cohabited (HR, 1.60; 1.29-1.98). Socioeconomic differences in survival were partly explained by cancer stage and less by comorbidity or smoking (stage-and comorbidty-adjusted HRs being 1.07; 0.96-1.19 for education and 1.15; 0.86-1.52 for income). Conclusion: Socioeconomic disparities in survival after cervical cancer were partly explained by socioeconomic differences in cancer stage. The results point to the importance of further investigations into reducing diagnosis delay among disadvantaged groups.