Tumor growth factor expression in obesity and changes in expression with weight loss: another cause of increased virulence and incidence of cancer in obesity

Abstract Background Obesity is associated with increased tumerogenesis. Previously, we demonstrated that inflammation in obesity caused cancer fighting cells to display greater surface receptor levels, predisposing them to early cell death. We measured the inflammatory tumor growth factor levels to determine whether inflammation in obesity increases expression of these factors, potentially predisposing these patients to greater rates of neoplasia. Methods A total of 24 patients undergoing weight loss surgery had samples collected preoperatively and at 6 and 12 months after surgery. The growth factors analyzed included tumor necrosis factor (TNF)-α, granulocyte-macrophage colony-stimulating factor, interferon-γ, interleukin (IL)-1b, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, vascular endothelial growth factor, hepatocyte growth factor, TNF-receptor I (TNF-RI), TNF-RII, death receptor 5, leptin, and adiponectin. Control samples were obtained from 10 healthy, normal weight volunteers. Results The tumor growth factors TNF-α, TNF-RI, TNF-RII, vascular endothelial growth factor, hepatocyte growth factor, interferon-γ, IL-2, IL-5, and IL-6 all decreased significantly ( P Conclusion Many inflammatory tumor growth factors are present in greater concentrations in obese individuals. This could explain the greater prevalence of neoplasia in the morbidly obese population.