Socioeconomic Status Affects Long Term Childhood Leukemia Survival

Professor Eleni Petridou Preventive Medicine & Epidemiology, Department of Hygiene Epidemiology and Medical Statistics, Athens University Medical School Athens Interview with:
Professor Eleni Petridou

Preventive Medicine & Epidemiology, Department of Hygiene
Epidemiology and Medical Statistics,
Athens University Medical School Athens Greece

Medical Research: What is the background for this study? What are the main findings?

Prof. Petridou: Impressive gains in survival from childhood leukemia have been achieved during the last decades mainly on account of advancements in treatment of the disease. Yet, these big improvements do not seem to be equally shared by all sick children. Disparities in the survival of children suffering leukemia who live in high versus low-income countries, as well as among different racial groups pointed to socio-economic status (SES) of the family as a factor that might adversely affect the outcome. SES, however, is a multifaceted variable comprising economic, social and professional components, which cannot be easily assessed. Therefore, an array of area of residence- and individual family- based proxy indices have been used in order to investigate the association between SES and overall or event-free survival from childhood leukemia. We have intensively searched for published articles around the globe and also analyzed primary data kindly provided by the US National Cancer Institute Surveillance, Epidemiology and End Results Program (SEER) for the period 1973-2010 as well as the Nationwide Registry for Childhood Hematological Malignancies (NARECHEM) in Greece for the period 1996-2011. This study is the first meta-analysis summing up the findings of 29 individual studies and quantifying the adverse effect in the survival due to SES differentials among 60 000 afflicted children. According to the findings, lower socio-economic status children suffering, at least, the more common Acute Lymphoblastic Leukemia (ALL) type have nearly two fold higher death rates compared to those of high socio-economic status. Of note, the SEER data show that the survival gap was wider in the USA with increased risk of death from ALL in the lower SES children (by 20-82%) and widening during the last 40 years time period.

Medical Research: What should clinicians and patients take away from your report?

Prof. Petridou: Various mechanisms may underlie the observed disparities in prognosis of children suffering Acute Lymphoblastic Leukemia due their SES ranging from delays in the diagnosis to inadequate health insurance, restricted access to quality health care and participation in ongoing clinical trials along with gaps in the understanding of guardians, especially those of low educational level or ethnic minorities of how they are instructed to provide nowadays pertinent out-hospital treatment, which under contemporary protocols is a high proportion of the treatment schedule. In this context, low socio-economic status seems to be linked with poorer adherence or even abandonment of treatment.

Consequently, health policy makers should provision adequate structures and means allowing treating personnel to ensure proper discharge plans after screening families at risk and to envision close follow-up of the child through home visits, as needed. It is worthwhile mentioning that in the Greek context it has been also found that single parenthood is a more critical factor for childhood leukemia prognosis compared to parental education per se or remoteness of residence from the treating center. To this end, Australia has already introduced special assistance schemes for relatives of lonely patients with cancer as to remove this type of barriers. Moreover, in case of delays in undertaking action on the part of the responsible authorities, parental interest groups avail now the quantified argumentation to lobby for the minimal changes needed in the legislation that would improve disease outcomes and quality of family life of young age leukemic patients and reduce health inequalities even in these early stages of life. Thus, we hope that our findings will stimulate further interest for removal of obstacles, which do not allow children born in less privileged environments to benefit from the most recent therapeutic advancements in childhood leukemia and related diseases, following the examples of a few countries, which have achieved to minimize these inequalities.

Medical Research: What recommendations do you have for future research as a result of this study?

Prof. Petridou: Reducing socioeconomic health differentials, in general and childhood leukemia, in particular is not an easy task. Moreover, this type of research is not eye-catching for potential sponsors. Yet, the paradigms of the few studies showing that these inequalities can be minimized, present the gold standards against which the rest of the societies should be benchmarked regarding respect for the minors and social sensitivity issues. Once we know that the target is achievable, it depends on the treating physicians and the parental groups to raise social awareness and advocate on the need for further research to explore how to tailor these results to their home countries.

In particular, (1) the role of specific components of socio-economic status and (2) the health care system delivery differentials along with the effectiveness of specific health policy measures conducive to the reduction of these inequalities should be explored.

We found a paucity of studies deriving from the underprivileged areas of Africa and Asia, whereas the tentative role of race as a genetic factor in comparison to that as a socio-economic status has to be disentangled. To this end, current research efforts also address the complexity of the SES in an attempt to come up with a composite more robust SES index.


Citation: Petridou ET, Sergentanis TN, Perlepe C, Papathoma P, Tsilimidos G, Kontogeorgi E, et al. Socio-economic disparities in survival from childhood leukemia in the U.S.A. and globally: a meta-analysis. Ann Oncol. 2014.
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