Quote Originally Posted by New England Journal of Medicine
The second consideration is the effect of long-term administration of growth hormone. It is not known whether long-term administration of growth hormone in the elderly is potentially harmful — particularly with regard to the risk of cancer, given that older age is associated with an increased incidence of cancer. In 152 healthy men, the relative risk of the subsequent development of prostate cancer was increased by a factor of 4.3 among men who had serum concentrations of insulin-like growth factor I in the highest quartile, as compared with those whose concentrations were in the lowest quartile.6 This finding does not demonstrate causality by growth hormone or insulin-like growth factor I, but it does raise concern about giving older men growth hormone, which increases serum concentrations of insulin-like growth factor I.