Keep It Moving: Physical Activity in the Prevention of Obesity-Driven Pancreatic Cancer.

Despite the already dire impact of pancreatic cancer, a growing subset of patients with obesity exhibits an amplified risk of disease and worse outcomes. Mouse models have revealed that obesity is distinctly pathogenic, accelerating pancreatic ductal adenocarcinoma (PDAC) progression and inducing increased desmoplasia and myeloid cell infiltration in the tumor microenvironment. However, whether and how obesity-countering interventions, such as exercise, reverse the protumorigenic effects of obesity is incompletely understood. In this issue of Cancer Research, Pita-Grisanti and colleagues investigate the impact of physical activity (PA) in disrupting obesity-driven PDAC. Employing a variety of sophisticated models, including autochthonous genetically engineered mice, orthotopic syngeneic allografts, high-fat diet-induced obesity, and PA interventions in mice and humans, the authors found that PA impedes PDAC development in obese mice but does not impact the growth of advanced tumors. These antitumor effects correlated with reduced inflammation and fibrosis in the tumor microenvironment, a decline in high-fat diet-induced circulating inflammatory cytokines, and an increase in the IL15 signaling axis in white adipose tissue. Although adipose-targeted IL15 therapy was effective in suppressing advanced tumor growth in lean mice, obese mice were resistant to its therapeutic benefits. Together, the findings argue that PA delays obesity-driven early PDAC progression, implicating the preferential benefit of exercise as a preventative strategy. They further identify changes in obesity-associated local and systemic cytokine production as a possible mechanism for the antitumor effects of PA and help define context-specific determinants of response for emerging IL15-based immunotherapies. See related article by Pita-Grisanti et al., p. 3058.