Null association between insulin-like growth factors, insulin-like growth factor-binding proteins, and prostate cancer in a prospective study.

Introduction IGF-1 regulates normal and neoplastic growth in the prostate (1), and higher serum IGF-1 levels (2) appear to increase prostate cancer risk in epidemiological studies. Other aspects of the IGF axis, such as IGFBP-3 (3), inconsistently affect risk. Retrospective studies dominate the literature on this topic, and we, therefore, investigated IGF-I and IGFBP-3 in a pilot study from the Clue I population, a prospective cohort study based on the Washington County Serum Bank in Maryland. We hypothesized that higher serum IGF-1 and lower serum IGFBP-3 are associated with an increased risk of developing prostate cancer.