Socioeconomic aspects within childhood cancer

Background: Childhood cancer survivors are proposed to face survival and mortality disparities based on socioeconomic factors even in high-income countries. Race and ethnicity have also been shown to influence mortality and survival from childhood malignancies, but the effect of immigrant status has not been widely investigated. Furthermore, childhood cancer survivors face adverse socioeconomic consequences later in life. This thesis aimed to investigate the effect of parental socioeconomic status, family circumstances, and immigrant status on childhood cancer mortality and survival in Finland. Another aim was to assess whether survivors of childhood cancer are more likely to experience low income in adulthood than their peers in Finland, Denmark, and Sweden. Materials and methods: For the first two studies, 4,437 patients diagnosed with cancer under the age of 20 years in 1990–2009 were identified from the Finnish Cancer Registry. Parents and siblings of the patients were identified from the population registry. Information on demographic factors and death from primary cancer during five-year follow-up was obtained from Statistics Finland. Hazard ratios (HRs) for cancer deaths were estimated using Poisson regression modelling. The recursion tree method was used to identify key risk factors for mortality, and the life table method and the log rank test were used in survival analysis. For the third study, 17,392 childhood cancer survivors diagnosed at the age of 0 to 19 years in 1971–2009 with 83,221 population comparisons matched by age, sex, and country were identified from the national cancer registries and population registries in Finland, Denmark, and Sweden. Annual disposable income for 1990–2017 between 20 to 50 years of age was retrieved from national statistical offices and categorized into low income and middle/high income based on the risk-of-poverty-rate as defined by Eurostat. The prevalence of income status and the number of transitions between the two income categories were assessed using binomial regression analyses. Results: Childhood cancer mortality was lower when the parents were in the highest quartile of combined disposable income compared to the lowest quartile. In the most recent diagnostic period in 2000–2009, post-secondary education of either parent predicted lower mortality for the child compared to children of parents with primary or lower education. Mortality was higher if the patient or the parents were of foreign background and born abroad compared to those of Finnish background and born in Finland. If native language of the parents was other than Finnish or Swedish, childhood cancer mortality was higher compared to those with Finnish or Swedish as their native language. Childhood cancer survivors experienced higher prevalence of low income than population comparisons and were less likely to transition from low income to middle/high income and more likely to transition from middle/high income to low income during follow-up. Survivors were also more likely to permanently remain in the low income category. Conclusions: Regardless of the universal welfare societies with universal health care and social security, disparities in childhood cancer mortality and income situation of adult childhood cancer survivors exist. Probable explanations may rise from lower health literacy and financial strains limiting treatment adherence in children with less educated parents and parents with lower income. Immigrants in turn may face cultural barriers and linguistic obstacles that lead to difficulties in navigating the health care system. Higher risk for low income among childhood cancer survivors may constitute from educational hardships, unemployment, or early retirement. Families at risk need motivation and support, and cultural and linguistic aspects should be considered when treating immigrant children. Furthermore, the income disparities among adult survivors of childhood cancer might be reduced by continued career counselling and support in managing within the social security system.