Resistin and omentin in breast cancer: A systematic review and meta-analysis

: Breast cancer (BC) is the most frequently diagnosed cancer and a leading cause of cancer-related mortality among women globally. Resistin, omentin and ghrelin, adipokines involved in inflammation and metabolic regulation, have been implicated in cancer development, yet their associations with BC remain unclear. This systematic review and meta-analysis aimed to elucidate the relationships between resistin, omentin, and ghrelin concentrations and BC, while exploring potential moderators such as body mass index (BMI) and menopausal status. A comprehensive search of electronic databases up to 13 May 2024 identified studies comparing resistin and omentin, but not ghrelin, concentrations in BC patients and healthy controls. Standardized mean differences (SMDs) were calculated using random-effects models, and meta-regression and subgroup analyses were performed to investigate sources of heterogeneity. Analysis of 11 studies showed that BC patients exhibited significantly higher resistin concentrations compared to controls, with a pooled SMD of 2.05 (95 % CI 1.24 to 2.86, p < 0.001). Meta-regression indicated that BMI significantly moderated the resistin-BC association (p = 0.003). In contrast, omentin concentrations presented a complex picture, with a pooled SMD of -0.27 (95 % CI -1.39 to 0.84, I^2 = 96.2 %, p < 0.001), indicating substantial heterogeneity and inconclusive results, whereas only one study investigated ghrelin. Our findings support a significant association between elevated resistin concentrations and BC, suggesting a potential role of resistin in BC pathophysiology. The data on omentin and ghrelin remain inconclusive, warranting further investigation. Future research should focus on large, longitudinal studies with standardized methodologies to validate these findings and clarify the role of adipokines in BC.