Socioeconomic Differences and Lung Cancer Survival—Systematic Review and Meta-Analysis

Abstract

Background: The impact of socioeconomic differences on cancer survival has been investigated for several cancer types showing lower cancer survival in patients from lower socioeconomic groups. However, little is known about the relation between the strength of association and the level of adjustment and level of aggregation of the socioeconomic status measure. Here, we conduct the first systematic review and meta-analysis on the association of individual and area-based measures of socioeconomic status with lung cancer survival.Methods: In accordance with PRISMA guidelines, we searched for studies on socioeconomic differences in lung cancer survival in four electronic databases. A study was included if it reported a measure of survival in relation to education, income, occupation, or composite measures (indices). If possible, meta-analyses were conducted for studies reporting on individual and area-based socioeconomic measures.Results: We included 94 studies in the review, of which 23 measured socioeconomic status on an individual level and 71 on an area-based level. Seventeen studies were eligible to be included in the meta-analyses. The meta-analyses revealed a poorer prognosis for patients with low individual income (pooled hazard ratio: 1.13, 95 % confidence interval: 1.08–1.19, reference: high income), but not for individual education. Group comparisons for hazard ratios of area-based studies indicated a poorer prognosis for lower socioeconomic groups, irrespective of the socioeconomic measure. In most studies, reported 1-, 3-, and 5-year survival rates across socioeconomic status groups showed decreasing rates with decreasing socioeconomic status for both individual and area-based measures. We cannot confirm a consistent relationship between level of aggregation and effect size, however, comparability across studies was hampered by heterogeneous reporting of socioeconomic status and survival measures. Only eight studies considered smoking status in the analysis.Conclusions: Our findings suggest a weak positive association between individual income and lung cancer survival. Studies reporting on socioeconomic differences in lung cancer survival should consider including smoking status of the patients in their analysis and to stratify by relevant prognostic factors to further explore the reasons for socioeconomic differences. A common definition for socioeconomic status measures is desirable to further enhance comparisons between nations and across different levels of aggregation.

Influence of timeliness and receipt of first treatment on geographic variation in non‐small cell lung cancer mortality

“…Two‐year all‐cause mortality of ever‐smokers was significantly higher than that of never‐smokers, consistent with this cohort study 46 . Studies reporting an association between reduced lung cancer survival and low individual income and area‐level SES in the meta‐analysis did not adjust for relevant prognostic factors like smoking 47,48 . Even after controlling for underlying prognostic factors, there was still some contextual effect of area‐level deprivation found in our study.…”

Assessment of the concordance between individual-level and area-level measures of socio-economic deprivation in a cancer patient cohort in England and Wales

“…For example, within oncology a small number of studies have examined the relative effects of individual-level and ecological-level deprivation on both cancer risk [14][15][16] and outcomes. [17][18][19] Generally, these studies have quantified independent effects of both individual and ecological deprivation, and for both, more deprived areas or individuals have higher risk and lower survival. 14 17-19 However, the strength and nature of these trends varies considerably across factors including sex, level of geographical aggregation and which type of deprivation metric is used.…”

“…14 17-19 However, the strength and nature of these trends varies considerably across factors including sex, level of geographical aggregation and which type of deprivation metric is used. 18 Furthermore, these associations are not well understood in a UK context, especially in terms of making use of recent data, and an improved understanding will be important in order to reduce inequalities as part of the National Health Service (NHS) long-term plan for 2020 to 2030. 20 The research on health inequalities on which the NHS long-term plan is based uses data aggregated to small area level, and so improving our understanding of how reliably this matches individual-level circumstances is important in terms of developing further policies which more specifically target individual-level variation in health outcomes.…”

Educational level, management and outcomes in small-cell lung cancer (SCLC): A population-based cohort study

“…The two-year overall survival rate is 20-40% in LD and 5 % for ED [4]. Several studies have described an association between socioeconomic status and the risks of developing Non-Small Cell Lung Cancer (NSCLC) [5,6]. A previous Swedish study based on a regional cohort of NSCLC patients found evidence of socioeconomic gradients in diagnostic intensity, choice of treatment and outcomes [7].…”