IGF is a growth factor in the body that is common in growing children, states the Harvard University Gazette. It stands for insulin-like growth factor. Studies at the Harvard School of Public Health found this factor has links to certain cancers.
In studies at the Harvard School of Public Health, IGF-1 increased the risk of colorectal, breast and prostate cancer, says the Harvard University Gazette.
The body makes growth hormones in the pituitary gland, explains WebMD. When the body releases these hormones, it also releases other substances that promote growth and increase metabolism, which doctors call factors. IGF-1 is one example of a growth hormone factor that correlates to high levels of growth hormones in the body. Doctors test the blood for IGF-1 levels to determine if a patient has high growth hormone levels.
One condition caused by an excess of IGF is acromegaly, states the Mayo Clinic. When the pituitary gland overproduces growth hormones, it causes the liver to produce IGF-1. This substance triggers the bones and tissues of the body to grow. In patients who have overactive pituitary glands, IGF-1 causes gigantism, in which the skeleton and soft tissues continue to grow abnormally. Most overproduction of this factor is caused by benign tumors in the gland. In rare cases, tumors outside of the gland produce growth hormones themselves, causing an increase in IGF-1.