IGF1 and cancer: The positive correlation between IGF-1 expression and cancer has been widely reviewed with one study that included 18 years of follow-up reporting a 1.82-fold risk of cancer mortality among men who had a baseline IGF-1 level above 100 ng/mL compared with men with lower levels, a risk that was increased to 2.61 for men who had a baseline IGF-1 level over 200 ng/mL [51].