Serum resistin is inversely related to breast cancer risk in premenopausal women.

BACKGROUND: Adipokines have been suggested as potential mediators linking obesity and breast cancer. Resistin is the least-studied adipokine with diverse findings regarding its association with disease development and progression. The present study aimed to determine resistin serum levels in breast cancer in relation to the histological type of disease and to investigate their association with breast cancer risk. METHODS: The study included 216 women, of which 163 were diagnosed with breast cancer (58 with IDC, 52 with DCIS and 53 with LN) and 53 were healthy. Serum levels of resistin, leptin and adiponectin were quantitatively determined in duplicates by ELISA. Differences in resistin levels among patient groups were evaluated with Kruskal-Wallis and Mann-Whitney tests. The association of resistin with breast cancer risk was evaluated by multiple logistic regression analysis. RESULTS: Resistin levels varied between histological types of breast cancer (p = 0.044). Significant differences in serum resistin were observed in IDC patients compared to those with DCIS and to controls (p < 0.014 and p < 0.03, respectively). Decreased levels of resistin, adiponectin and leptin were observed in premenopausal patients. Resistin was associated with a reduced risk for ductal carcinoma only in premenopausal women (OR: 0.364, 95% CI: 0.154-0.862, p < 0.022). CONCLUSION: Our findings indicate that resistin levels were inversely related to breast cancer risk in premenopausal women, supporting a protective role of resistin for these patients. Further advances in adipokine research may lead to tangible benefits for overweight/obese women at an increased risk for breast cancer.

Serum irisin levels are lower in patients with breast cancer: association with disease diagnosis and tumor characteristics.

BACKGROUND: Irisin is a recently discovered myokine, involved in the browning of white adipose tissue. To date, its function has been mainly associated with energy homeostasis and metabolism, and it has been proposed as a promising therapeutic target for obesity and metabolic diseases. This is the first study investigating the role of irisin in human breast cancer. METHODS: Participants included one hundred and one (101) female patients with invasive ductal breast cancer and fifty one (51) healthy women. Serum levels of irisin, leptin, adiponectin and resistin were quantified in duplicates by ELISA. Serum levels of CEA, CA 15-3 and Her-2/neu were measured on an immunology analyzer. The association between irisin and breast cancer was examined by logistic regression analysis. The feasibility of serum irisin in discriminating breast cancer patients was assessed by ROC curve analysis. Potential correlations with demographic, anthropometric and clinical parameters, with markers of adiposity and with breast tumor characteristics were also investigated. RESULTS: Serum levels of irisin were significantly lower in breast cancer patients compared to controls (2.47 ± 0.57 and 3.24 ± 0.66 µg/ml, respectively, p < 0.001). A significant independent association between irisin and breast cancer was observed by univariate and multivariate analysis (p < 0.001). It was estimated that a 1 unit increase in irisin levels leads to a reduction in the probability of breast cancer by almost 90%. Irisin could effectively discriminate breast cancer patients at a cut-off point of 3.21 µg/ml, with 62.7% sensitivity and 91.1% specificity. A positive association with tumor stage and marginal associations with tumor size and lymph node metastasis were observed (p < 0.05, p < 0.01, p < 0.01, respectively). CONCLUSIONS: Our novel findings implicate irisin in breast cancer and suggest its potential application as a new diagnostic indicator of the presence of disease.