Metabolic Dysfunction–Associated Carcinogenesis: Molecular Mechanisms and the Preventive Roles of Phytochemicals Part I: Pathophysiological Mechanisms Linking Metabolic Dysfunction to Cancer

The global cancer burden is projected to escalate to 27 million new cases annually by 2040, a trajectory that parallels the rising prevalence of obesity, metabolic dysfunction, and related metabolic disorders. While genetic and environmental factors are well-recognized, the systemic metabolic environment is increasingly identified as a critical determinant of tumorigenesis. This review (Part I) systematically delineates the molecular and cellular framework through which metabolic dysfunction orchestrates a tumor-permissive landscape. We evaluate six primary pathophysiological axes: (1) chronic low-grade inflammation that fuels a protumorigenic milieu, (2) oxidative stress and redox imbalance leading to genomic instability, (3) insulin resistance and insulin-like growth factor axis activation which stimulate mitogenic pathways, (4) aberrant lipid metabolism and lipotoxicity-driven cell transformation, (5) gut microbiota dysbiosis and its modulation of the tumor microenvironment, and (6) metabolism-associated epigenetic remodeling that sustains oncogenic gene expression. Unlike previous literature that has focused on isolated pathways, this synthesis emphasizes the synergistic crosstalk among these mechanisms, illustrating how they collectively reinforce cancer initiation and progression. Furthermore, this mechanistic framework provides a biological rationale for targeting metabolism-associated carcinogenesis through dietary phytochemicals and bioactive compounds, which will be comprehensively discussed in Part II. By providing an integrated overview of the metabolic dysfunction–cancer axis, this work establishes a mechanistic foundation for the preventive potential of phytochemicals. These insights are crucial for developing multitarget dietary strategies against metabolism-associated malignancies.