Hyperresistinemia and metabolic dysregulation: a risky crosstalk in obese breast cancer

Breast cancer is the most common malignancy among women worldwide. There is extensive literature on the relationship between body weight and breast cancer risk but some doubts still remain about the role of adipokines per se, the role of insulin and glucose regardless of obesity, as well as the crosstalk between these players. Thus, in this study, we intend to determine the relation between body mass index (BMI), glycaemia, insulinemia, insulin-resistance, blood adipokine levels and tumour characteristics in a Portuguese group of pre- and postmenopausal overweight/obese women with breast cancer. We evaluated clinical and biochemical data in 154 participants, divided in 4 groups: (1) control with BMI <25 kg/m², n = 29 (CT); (2) control with BMI >25 kg/m², n = 48 (CTOb); (3) breast cancer with BMI <25 kg/m², n = 30 (BC); and (4) breast cancer with BMI >25 kg/m², n = 47 (BCOb). In women with breast cancer, we also performed tumour characterization. We found that BCOb present increased fasting blood glucose, insulin, resistin and monocyte chemoattractant protein 1, insulin resistance and more aggressive tumours. Notably, this profile is not correlated with BMI, proposing the involvement of other processes than adiposity. Altogether, our results suggest that glucose dysmetabolism, insulin resistance and changes in adipokine secretion, in particular resistin, may be involved in the development and progression of breast cancer in overweight/obese pre- and postmenopausal women.