Abstract
Skeletal muscle is increasingly recognized as an endocrine organ, and contraction-induced myokines are viewed as key mediators of the systemic benefits of exercise. This review synthesizes evidence on the roles and molecular mechanisms of major myokines-including IL-6, irisin, SPARC, oncostatin M (OSM), and decorin-in exercise-associated modulation of cancer-related inflammation and tumor progression. We propose two principal routes: direct effects on tumor cells (e.g., reduced proliferation and metastatic potential) and indirect effects mediated by remodeling of the tumor immune microenvironment. Nevertheless, the literature remains heterogeneous, and reported effects are strongly context dependent, contributing to ongoing debate. Personalized exercise prescriptions, together with deeper mechanistic studies, may accelerate the clinical translation of myokines as biomarkers and potential therapeutic targets.