Abstract 4938: Socioeconomic position and survival after lung cancer diagnosis: Comparisons in 4 continents
Authors: Justina Ucheojor Onwuka, Karine Alcala, Hilary A. Robbins, Mattias Johansson, The Lung Cancer Cohort Consortium
Journal: Cancer Research (2025)

Background: The incidence of lung cancer is lower among higher socioeconomic position (SEP) groups in most settings. It is important to assess whether this translates to disparities in survival by SEP after lung cancer diagnosis. We sought to describe the relationship between SEP and survival after lung cancer diagnosis across different countries. Methods: We analyzed data from the Lung Cancer Cohort Consortium (LC3) and included 18 prospective cohorts from 14 countries in North America, Europe, Asia, and Australia. The total sample size included 48,482 lung cancer cases with pre-diagnostic risk factor information, amongst whom 37,559 died during the follow-up (median, IQR= 10.8, 6.5-15.0 years). Information on education was harmonized using the International Standard Classification of Education and then modeled as an ordinal variable in 4 categories. We evaluated the relationship between educational level and survival after lung cancer diagnosis using Cox proportional hazards models. Models were adjusted for age at diagnosis, sex, and (where applicable) cohort, smoking duration, cigarettes per day, and time since cessation. Results: We observed a clear trend toward better survival in participants with higher educational level in lung cancer cases diagnosed in North America, Europe and Asia, but not in Australia. After accounting for detailed smoking history, the hazard ratios were partly attenuated (North America: hazard radio per 1-unit increase in educational level [HR]=0.94, 95%CI=0.93-0.96; Europe: HR=0.94, 95%CI: 0.92-0.95; Asia: HR=0.81, 95%CI=0.77-0.85), but not in Australia. When additionally adjusting for stage at diagnosis, the inverse relationship between educational level and survival was further attenuated in Asian lung cancer cases, but not in European or North American study participants. We estimated that differences in tobacco exposure mediated approximately 20% of the relationship between education and lung cancer survival, and that disease stage mediated an additional 14% of this relationship in Asian lung cancer cases. Conclusion: Higher educational attainment is consistently associated with better lung cancer survival in North America, Europe, and Asia. Differences in tobacco exposure may partly, but not entirely mediate this relationship, and differences in stage at diagnosis may be additionally important in mediating the survival differences seen in Asian lung cancer cases. This study highlights the importance of socioeconomic position in the continuum of lung cancer disparities. Citation Format: Justina Ucheojor Onwuka, Karine Alcala, Hilary A. Robbins, Mattias Johansson, The Lung Cancer Cohort Consortium. Socioeconomic position and survival after lung cancer diagnosis: Comparisons in 4 continents [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 4938.