IGFBP3 and breast cancer: With regard to the association between the biomarkers of IGF system and the prognosis of breast cancer, studies are limited and have revealed controversial findings suggesting a positive association (10), an inverse association (11), or no clear association of IGF1 or IGFBP3 with adverse outcomes after breast cancer including all-cause or breast cancer-specific mortality and breast cancer recurrence (12, 13).