Long-term follow-up with patients with acromegaly, characterized by chronic elevation of circulating GH and IGF-1, have reported an association with certain cancers, but this remains controversial, as confounding factors such as age, comorbidities, and genetic predispositions may be causative, rather than increased GH and IGF-1 [5,121,122]. This evidence concerns the gene IGF1 and acromegaly.