A Novel Automated Immunoassay Platform to Evaluate the Association of Adiponectin and Leptin Levels with Breast Cancer Risk

SIMPLE SUMMARY: Adiponectin and leptin are adipokines secreted by the adipose tissue that have been associated with several chronic diseases including cancer. We compared two methods for their measurement and investigated their association with breast cancer. We measured adiponectin and leptin with the automated ELLA platform and a manual commercially available enzyme-linked immunosorbent assay (ELISA) kit on serum samples of women enrolled in two international breast cancer prevention trials. We found a good concordance between the two methods and our results support the association of low adiponectin levels with breast cancer, irrespective of the method used. The take-home message is that ELLA is a very robust platform that represents a step forward for the future use of adipokines, along with other biomarkers, in clinical cancer risk assessment and prevention. Its use should be taken into account whenever biomarkers should be measured in a large cohort of patients for clinical validation or cancer association studies. ABSTRACT: Adiponectin and leptin are adipokines secreted by the adipose tissue that are associated with several chronic diseases including cancer. We aimed to compare the immunoassay platform ELLA with an enzyme-linked immunosorbent assay (ELISA) kit and to assess whether the results of the association analyses with breast cancer risk were dependent on the assay used. We measured adiponectin and leptin with ELLA and ELISA on baseline serum samples of 116 Italian postmenopausal women enrolled in two international breast cancer prevention trials. Results were compared with Deming, Passing–Bablok regression and Bland–Altman plots. Disease-free survival was analyzed with the Cox model. There was a good correlation between the methods for adiponectin and leptin (r > 0.96). We found an increased breast cancer risk for very low adiponectin levels (HR for ELLA = 3.75; 95% CI: 1.37;10.25, p = 0.01), whereas no significant association was found for leptin levels. The disease-free survival curves were almost identical for values obtained with the two methods, for both biomarkers. The ELLA platform showed a good concordance with ELISA for adiponectin and leptin measurements. Our results support the association of very low adiponectin levels with postmenopausal breast cancer risk, irrespective of the method used. The ELLA platform is a time-saving system with high reproducibility, therefore we recommend its use for biomarker assessment.