IGFBP3 and breast cancer: Our finding of a lack of association between postmenopausal circulating levels of IGF-I and IGFBP-3 with subsequent breast cancer risk, albeit based on only 47 breast cancer cases, are also consistent with those reported by most other prospective studies, although the recent study of Grønbæk et al (2004) reported a positive association between IGFBP-3 and breast cancer risk.