IGF1 and breast cancer: In this study, taking advantage of a large prospective cohort study, we examined the associations of IGF1 as well as other biomarkers of insulin and the IGF axis including insulin, C-peptide, IGFBP3, and the IGF1/IGFBP3 ratio with all-cause mortality, breast cancer-specific mortality, and breast cancer recurrence in women with invasive breast cancer.