Circulating insulin-like growth factor-I and binding protein-3 and risk of prostate cancer

Abstract

Some recent epidemiologic studies have failed to confirm positive associations between insulin-like growth factor-I (IGF-I) and the risk of prostate cancer observed in earlier studies but have reported suggestive evidence for a positive association between IGF-binding protein-3 (IGFBP-3) and prostate cancer risk, a result contradicting the earlier assumption that high levels of IGFBP-3 would be protective against prostate cancer. We tested the association between IGF-I and IGFBP-3 and prostate cancer risk by measuring the two peptides in plasma samples collected at baseline in a prospective cohort study of 17,049 men. We used a case-cohort design, including 524 cases diagnosed during a mean ..