Family Socioeconomic Position and Lung Cancer Risk: A Meta-analysis and a Mendelian Randomization Study

Abstract

BackgroundFamily socioeconomic position (SEP) in childhood is an important factor to predict some chronic diseases. However, the association between family SEP in childhood and the risk of lung cancer is not clear. MethodsA systematic search was performed to explore their relationship. We selected education level, socioeconomic positions of parents and childhood housing conditions to represent an individual family SEP. Hazard ratios (HRs) of lung cancer specific-mortality were synthesized using a random effects model. Two-sample Mendelian randomization (MR) was carried out with summary data from published genome-wide association studies of SEP to assess the possible causal relationship of SEP and risk of lung cancer. ResultsThrough meta-analysis of 13 studies, we observed that poorer SEP was associated with increased lung cancer risk (HR: 1.25, 95% CI: 1.10, 1.43). In addition, the dose-response analysis revealed a negative correlation between SEP in childhood and lung cancer in adulthood. Same conclusion was reached in MR [(education level) OR 0.50, 95% CI: 0.39, 0.63; P: <0.001]. ConclusionsThis study indicates that poor family SEP in childhood is a causal risk factor for lung cancer. We believe this population may receive greater benefit from lung cancer screening programs.Systematic review registrationProspero ID: 159082

Socio-Economic Inequalities in Lung Cancer Outcomes: An Overview of Systematic Reviews

“…For instance, SES-based differences in stage at diagnosis could emerge in areas with population screening programs if there are underlying SES-based differences in screening eligibility and utilization, something that would widen the gap in survival between people with high vs. low SES. [6,10,11,17,19,28,31,32] and stars denote additional reviews [9,12,14,16,18,34].…”

“…Regarding cancer mortality, one review associated lower SES during childhood with higher cancer mortality during adulthood [ 28 ]. This review was still in a pre-print stage and received a “low confidence” rating due to multiple flaws.…”

“… Summary of the available evidence about socio-economic inequality in lung cancer outcomes. Circles denote articles included in the overview of systematic reviews [ 6 , 10 , 11 , 17 , 19 , 28 , 31 , 32 ] and stars denote additional reviews [ 9 , 12 , 14 , 16 , 18 , 34 ]. …”

“…Finally, only one of the identified reviews (Wang et al on the effect of childhood SES on lung cancer mortality [ 28 ]) considered analysis stratified by sex, finding similar results for men and women. The rest of the reviews did not investigate to what extent the effect of SES varied among men and women, something that should be addressed in future research.…”

“…We did not locate any reviews that met the inclusion criteria regarding incidence. Wang et al [28] investigated if childhood SES, defined as the education level or socioeconomic position of parents, and/or childhood housing conditions, influenced lung cancer mortality (number of studies k = 13). Lower childhood SES was associated with higher lung cancer mortality, HR = 1.25 (95% CI, 1.10, 1.42), p = 0.04, I 2 = 49%, k = 10 (from adjusted analysis, for lowest vs. highest SES).…”