Previous studies have implicated the growth hormone (GH)/IGF-I axis as an important mediator of cancer risk in humans and animals. Evidence supporting this notion is derived from animal studies, epidemiological observations, patients with acromegaly and from therapeutic manipulation of GH and IGF-I actions. Therefore, the use of GH therapy in patients with a history of malignancy raises hypothetical safety concerns. Reassuringly, GH therapy in childhood cancer survivors has not been confirmed to increase the cancer risk. Conversely, the risk of occurrence of a second neoplasm may be increased, with meningiomas being the most common tumor. In light of these findings, we propose considering GH therapy to be based on each individual's circumstance and commenced at least 2 years after cancer remission is achieved with close monitoring during therapy. More long-term data are needed on the safety of GH replacement therapy in GH-deficient adults with a history of malignancy.
Keywords: cancer; growth hormone; growth hormone deficiency; malignancy; review.