Increased Igf-I/Igfbp-3 Ratios in Postmenopausal Taiwanese with Breast Cancer, Irrespective of Er and Pr Statuses and Her2 Expression in a Case-Control Study

Background In most research, there were positive associations between the insulin‐like growth factor I (IGF‐I) status, including IGF‐I, insulin‐like growth factor binding protein‐3 (IGFBP‐3), and ratio of IGF‐I/IGFBP‐3, and risks of breast cancer (BC), which was influenced by many factors, including hormone statuses and ethnicity. Therefore, the alterations of the IGF‐I status in Taiwanese women with BC by menopausal statuses and hormone receptors were investigated. Methods The levels of IGF‐I and IGFBP‐3 were determined by the enzyme‐labeled chemiluminescent immunometric assay, and the protein expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor 2 (HER2) on paraffin‐embedded sections of tissues with BC were analyzed by the immunohistochemical method. Results The ratios of IGF‐I/IGFBP‐3 were significantly higher in the women with BC than those in the controls, but not of the levels of IGF‐I and IGFBP‐3; furthermore, the significantly higher ratios were found only in the postmenopausal status. In addition, there was no significant difference between the IGF‐I status and ER and PR statuses, and HER2 expression, respectively, in the women with BC. Conclusions The ratios of IGF‐I/IGFBP‐3 were increased in postmenopausal Taiwanese women with BC, irrespective of their ages, ER and PR statuses, and HER2 expression.