Abstract
Gastric cancer is the leading cause of cancer mortality among men and the second leading cause among women in Iran. Given the high incidence and mortality rates of this disease in the country, a deeper investigation into its effective causes is essential. One effective approach to uncovering the unknowns related to gastric cancer is the application of critical-deconstructive future-thinking tools, particularly Causal Layer Analysis (CLA). This qualitative study involved a review of theoretical foundations and meta-documents, along with interviews with a group of experts. By employing triangulation, the findings from the literature review were integrated with thematic analysis of the interviews through the CLA framework. At the litany layer, gastric cancer is identified as the second most prevalent and deadly cancer in Iran. The systemic layer explores the "social, technological, economic, environmental, and political" origins of gastric cancer, highlighting factors such as globalization, governance weaknesses, and cultural shifts. The third layer challenges the conceptualization of cancer as a metaphysical sin, advocating for a new narrative centered on Fundamental Prevention. Effective cancer control should focus on preventing the emergence and institutionalization of factors at the worldview and metaphorical levels that contribute to economic, political, social, and cultural attitudes, ultimately manifesting in high-risk behaviors and pathogenic processes. Designing complex social nudges is crucial for establishing this new narrative based on fundamental prevention. This study effectively combines a systematic literature review and semi-structured interviews to investigate the factors influencing gastric cancer in Iran through Causal Layer Analysis (CLA) and proposes a new layer to the conventional three-pronged prevention model called "fundamental level prevention." The findings suggest that interventions targeting worldviews and cultural beliefs can promote behavior change and enhance health outcomes, particularly among marginalized groups. Furthermore, prioritizing fundamental changes at these layers can lead to positive reductions in disease incidence. This research holds significant implications for international audiences, highlighting the complexities of gastric cancer and the necessity for cultural interventions and global collaboration to address this pressing health issue.