Serum adiponectin in breast cancer A meta-analysis

Background: Accumulating data have found that adiponectin is involved in development of breast cancer (BC). However, these results were inconsistent. Method: A systematic search in PubMed, Embase, ISI Web of Science, and Chinese National Knowledge Infrastructure databases were conducted up to October 1, 2017. The standardized mean difference (SMD) with 95% confidence interval was applied to pool the effect size. Results: Finally, 31 eligible studies were included in this meta-analysis. The overall results indicated that serum adiponectin levels in BC cases were significantly lower than the controls (SMD= -0.33, P<0.0001). As for the subgroup analysis of menstrual status, serum adiponectin levels were significantly lower in pre- and postmenopausal BC cases. Moreover, the subgroup analysis by ethnicity in pre-and postmenopausal group indicated an inverse association between adiponectin levels and BC risk in Asian population, but not in Caucasian population. Conclusion: The present meta-analysis suggests that low serum adiponectin concentration may be associated with an increased BC risk in premenopausal and postmenopausal women, especially among Asians. Adiponectin may serve as a biomarker of BC risk and help to identify subjects at high risk for BC development.