RESUMO
PURPOSE: Adiponectin is secreted from adipose tissue and is characterized by hyperinsulinemia which is related with obesity. Although serum adiponectin levels in patients with breast cancer have been studied previously, adiponectin levels in the serum, tumor and normal tissue of the same patients have not been simultaneously investigated. The aim of this study was thus to evaluate the relationship among serum, tumor and normal tissue adiponectin levels in patients with breast cancer. METHODS: Fifty-three patients with breast cancer who were operated at the Dr. Lutfi Kirdar Kartal Education and Research Hospital, Department of Surgery, between February 2008 and June 2008, were analyzed. Their serum adiponectin levels, tumor tissue and normal breast tissue adiponectin levels were compared. The correlation between postoperative histopathological parameters, insulin resistance parameters and adiponectin levels was also examined. RESULTS: The mean adiponectin levels in tumor tissue, normal breast tissue and serum were 56 ± 9.6 ng/ml, 56 ± 10 ng/ml and 43.5 ± 3.1 ng/ml, respectively. The serum adiponectin levels were inversely correlated with tumor tissue adiponectin levels (p=0.001, r=-0.43). When tumor tissue adiponectin levels were increased, serum adiponectin levels were decreased. O n the other hand, there was a positive correlation between normal breast tissue adiponectin levels and tumor tissue adiponectin levels (p=0.0001, r= 0.850). The tumor tissue adiponectin level was inversely correlated with tumor stage (p=0.037 , r= -0.29). Moreover, in early-stage and low grade tumors, both tumor tissue and normal tissue adiponectin levels were high compared with those of advanced stage or high grade tumors (p=0.027, r= -0.32 and p=0.004, r= -0.408, respectively). In the subgroup analyses, no significant relationship was found between insulin resistance parameters and adiponectin levels (p>0.05). CONCLUSION: Our results indicate that serum adiponectin levels were inversely correlated with tumor tissue adiponectin levels, but no relationship between normal breast tissue and tumor tissue adiponectin levels was demonstrated. Adiponectin levels in breast tumor tissue increase while serum adiponectin levels decrease. Adiponectin might play an important role in the prevention of tumor progression by decreasing tissue neovascularization.
