IGF1 and Familial prostate cancer: The role of IGF1 in prostate cancer was also examined in a retrospective study comparing a cohort of men with acromegaly (N=2495) with a reference cohort (N= 4.3 million), revealing an increased risk of prostate cancer diagnosis (HR 1.33, [95%CI 1.09–1.63], p = 0.005) (23).