The GH-IGF-I axis and breast cancer

Abstract

Breast cancer remains one of the most common causes of death amongst women today. Worldwide approximately 1.3 million women are diagnosed as having breast cancer every year. Much research has been done in trying to unravel the cause and behaviour of breast cancer and hormonal influences are known to play a role. In particular, two hormones known as growth hormone (GH) and insulin-like growth factor (IGF-1) have been found to play an important role in breast cancer growth and development. It has been found that women with breast cancer have higher levels of IGF-1 in their blood compared with women without breast cancer. Further studies have shown that if IGF-1 is added to breast cancer cells in laboratory conditions they grow rapidly. This evidence points to a strong link between IGF-1 and breast cancer. The majority of circulating IGF-1 is made by the liver in response to growth hormone, but as IGF-1 is also found in most cells in the human body, it is uncertain whether its possible effects on breast cancer may be due to local production of IGF-1 by breast cancer cells or to IGF-1 circulating in the blood. This research aims to study the link between IGF-1, GH and breast cancer. In order to do this, small specimens of breast tissue will be taken from women who are undergoing surgery for treatment of their breast cancer. Most cells removed will be cancer cells, but a rim of normal cells will surround them. I will then look at the different levels of IGF-1, growth hormone and other related hormones produced by the cancer or normal cells. During further research, I will aim to keep these cells alive for a few hours and see how they respond when various hormones are added to them. This research will give us more information about the hormonal control of breast cancer growth and may lead to novel treatments for breast cancer in the future.