Background: Expression of estrogen-regulated genes has been considered as potential predictive markers for endocrine therapy. We focused on two insulin-like growth factor binding proteins (IGFBPs): IGF BP-4, which is an early-responsive estrogen-induced gene, and IGF BP-5, which is an estrogen-repressed gene. Investigation of IGF BP-4 and IGF BP-5 expression would provide important information for predicting prognosis and endocrine responsiveness. Methods: The levels of IGF BP-4 and IGF BP-5 mRNA expression in 162 human breast cancer tissues were analyzed using quantitative real-time reverse transcriptase-PCR. The association between IGF BP-4 and IGF BP-5 expression and clinicopathological factors was then analyzed. Results The levels of IGF BP-4 and IGF BP-5 mRNA expression were positively correlated with estrogen receptor (ER) and progesterone receptor (PgR) status and were negatively correlated with HER2 overexpression. Patients with a high level of IGF BP-4 mRNA expression had better disease-free and overall survival than those with a low expression. Multivariate analysis showed that IGF BP-4 mRNA expression is an independent prognostic factor for disease-free survival. When analyzed in 116 patients with ER-positive breast cancer, patients whose tumor expressed higher levels of IGF BP-4 mRNA or lower levels of IGF BP-5 mRNA had better disease-free survival. Conclusion: IGF BP-4 mRNA expression was an independent prognostic factor in breast cancer, and patients with ER-positive breast cancer whose tumor expressed higher levels of IGF BP-4 and lower levels of IGF BP-5 had a better prognosis than those without such findings.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cancer Research