IGFBP3 and cancer: Large−scale epidemiological studies have demonstrated a link between high concentrations of IGF−I and many of the common cancers of adulthood, such as carcinomas of prostate, lung, breast and colon.(33, 34, 35)Overall, available data suggest that high levels of IGF−I and low levels of IGF binding protein−3 (IGFBP−3) are predictive of an increased cancer risk.