Levels of Key Protein Linked to Pancreatic Cancer Risk

People with lower blood levels of a protein called insulin-like growth factor-binding protein (1IGFBP-1) are more likely to develop pancreatic cancer than those with higher levels.

The risk may be elevated because higher amounts of IGFBP-1 are able to soak up more IGF, leaving less available to spur pancreatic cancer cell growth, or because IGFBP-1 has some cancer-blocking properties of its own. Another possibility is that other molecules may be involved, for which IGFBP-1 acts as an intermediary. Further work is required to determine whether 1IGFBP-1 is a reliable indicator of pancreatic cancer risk.

In a large study, investigators measured circulating IGFBP-1 levels in a select group of participants in four large, ongoing health studies: the Health Professionals Follow-up Study, the Nurses' Health Study, the Physicians' Health Study, and the Women's Health Initiative. They collected blood samples from 573 participants and, four or more years later, checked IGFBP-1 levels in the samples of 144 people who developed pancreatic cancer and 429 who did not.

They found that the quarter of the group whose IGFBP-1 levels were lowest had twice the risk of developing pancreatic cancer of those in the top three-quarters. The connection became even stronger over time--among cases diagnosed at least eight years after blood collection, those in the bottom quarter of IGFBP-1 levels had nearly three-and-a-half times the pancreatic cancer risk of those in the upper quarter. A report of the study appeared in the August 15, 2007, issue of the journal Cancer Research.

The levels of insulin and another circulating hormone, insulin-like growth factor or IGF, are modified by obesity and sedentary lifestyle, and there is evidence that these hormones may stimulate the growth of pancreatic cancer cells, said the study's lead author, Brian Wolpin, M.D, from Dana-Farber Cancer Institute (Boston, MA, USA). When IGF binds to proteins like IGFBP-1, there may be less IGF available to bind to pancreatic cancer cells and promote their growth. We wanted to determine whether IGFBP-1 levels in the blood were associated with pancreatic cancer risk.


Related Links:
Dana-Farber Institute