Suppressing Growth Hormone in Early Adulthood May Prevent Cancer
Human Growth Hormone and Cancer
A modest suppression of growth hormone and related compounds beginning in early adulthood may delay the onset or progression of several types of cancer, researchers from Wake Forest University School of Medicine and other centers reported today at ENDO 2005, the annual meeting of the Endocrine Society, in San Diego.
Suppression of growth hormone and insulin-like growth factor (IGF-1) also may decrease cancer risk in those individuals at high risk for disease, and perhaps could be a preventive measure, said William E. Sonntag. Ph.D., the lead investigator, who based his findings on research in rats. He said IGF-1 is an important blood-borne factor that increases cell growth and prevents cell death and has been proposed to be a factor in the initiation of cancer.
"Elevated IGF-1 levels in pre-menopausal women have been demonstrated to be a risk factor for breast cancer as well as numerous other cancers," said Sonntag, professor of physiology and pharmacology at the School of Medicine, a part of Wake Forest University Baptist Medical Center. IGF-1 in the blood also may act as a tumor promoter during the early development of cancer, he said.
Although additional research is needed, he said, drugs in the somatostatin class are currently available to suppress growth hormone and IGF-1 in people, so somatostatin analogs could be given as preventative measures to lower plasma IGF-1 before the onset of disease, especially in high-risk people.
In a previous study, rats with high levels of growth hormone (a circulating factor that increases IGF-1 levels) exhibit an increase in spontaneous mammary tumors. Dwarf animals with 50 percent lower IGF-1 levels do not develop tumors in response to a chemical carcinogen. But Sonntag said that if these dwarf rats are given growth hormone to increase IGF-1 in the blood, tumors develop at the same rate as in the normal animals.
Suppression of IGF-1 activity inhibits the proliferation of numerous cell types and cancers.